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Risk Dialogue Series

Genomic medicine

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Swiss Re Risk Dialogue Series: Genomic medicine 1

Editorial

Recent decades have seen massive advancements in genomic medicine. This has resulted in establishing a wealth of disease associations with genetic variances in the genome. At the same time, the extensive use of genome analysis tools has resulted in a massive decrease in the cost of genome sequencing. Today, genetic testing companies are offering full genome sequencing for below USD 1000.

The growing availability and utility of genetic information is becoming an increasingly important aspect of modern personalised medicine, due to the ability to deliver patient-tailored health care based on an individual’s genetic makeup. The emerging field of epigenetics, studying dynamically evolving changes in gene expression in response to environmental stresses, has added an additional layer of complexity to our understanding of the genome. As with genomic studies, current epigenetic research is rapidly evolving into potential clinical applications.

The latest advances in genetic science will improve disease diagnosis and aid in guiding and applying personalised treatment and prevention plans. These advances include liquid biopsy, which identifies cancer cells or DNA in bodily fluids, requiring minimally invasive extraction; and the development of CRISPR technology, which allows precise and efficient gene editing in any organism.

These new tools and techniques, combined with the growing availability of genomic information and new predictive methodologies, are entering clinical practice. They will challenge how we as insurers define disease; how we structure and price our policies; and how we sustainably provide our products and services to our customers.

We wish you an enjoyable read.

Edouard Schmid Christoph Nabholz Group Chief Underwriting Officer Head R&D Life & Health Swiss Re Swiss Re


Contents

Preface 1Edouard Schmid, Group Chief Underwriting Officer, Swiss ReChristoph Nabholz, Head R&D Life & Health, Swiss Re

Introduction 5Christoph Nabholz, Head R&D Life & Health, Swiss ReFlorian Rechfeld, Senior Research Analyst L&H, Swiss Re

Genomic medicine in clinical practice 9Vincent Mooser, Professor of Medicine and head of the Lab Department at Lausanne, CHUV University HospitalJacques Fellay, Head of the Precision Medicine Unit at the CHUV University Hospital in Lausanne

Transgenerational epigenetic inheritance: A paradigm shift in biology and medicine 21Johannes Bohacek, Group leader in the Mansuy lab at the Brain Research Institute of the University of ZurichIsabelle M Mansuy, Professor in Neuroepigenetics at the Medical Faculty of the University of Zurich

Liquid biopsy in oncology 31Nicola Aceto, Professor of Oncology and Group Leader of the Cancer Metastasis laboratory at the University of Basel

Liquid biopsy – a new blood test for cancer challenges the insurance industry 41Giselle Abangma, Health Research Analyst, Swiss Re Christoph Nabholz, Head R&D Life & Health, Swiss Re Florian Rechfeld, Senior Research Analyst L&H, Swiss Re John Schoonbee, Global Chief Medical Officer, Swiss Re

Future clinical applications of gene editing in humans 49Thomas Wildhaber, Analyst, Swiss ReChristoph Nabholz, Head R&D Life & Health, Swiss ReSéverine Rion Logean, Head Life & Health R&D Europe, Swiss Re


Introduction

Genomic medicine is an emerging branch of medicine that involves an individual’s unique genetic makeup to customise medical care. The present form of genomic medicine is a direct result of the human genome sequencing project which started in 1990 aiming to identify and map all of the human genes. Thirteen years and USD 3 billion later, the project had successfully sequenced the human genome. The year 2007 marked another turning point with the application of next generation-sequencing (NGS) technology to uncover the roles of rare individual genetic variances in common diseases. The cost of genome sequencing subsequently plummeted and currently stands at around USD 1000 (Figure 1). These technological advances have led to a major leap forward in the scope of genomics and its growing role in the delivery of healthcare.

Figure 1: Cost per genome

Genomic medicine in clinical practice

In the first article of this collection, Vincent Mooser, Professor of Medicine and Jaques Fellay, Head of the Precision Medicine Unit, both located at Lausanne CHUV University Hospital, explore genomic medicine in clinical practice. The authors conclude that the use of individual genetic information plays a key role in modern medicine and will fundamentally change the way we predict, prevent, diagnose and treat diseases in the near future.

Genetic testing will become a cornerstone of cancer diagnosis, allowing physicians to identify and classify tumours based on their genetic signatures in addition to their location in the body. Furthermore, results from genetic testing can be useful to evaluate the prognosis of an individual’s cancer and to cross-reference the results to known treatment options for a patient’s particular mutations.

Expectations are high that genetic testing will accurately predict the risk for various diseases and eventually lead to preventive and therapeutic interventions that are targeted to at-risk individuals based on their genetic profiles.

Latest research has led to the development of Genetic Risk Scores (GRS) combining individual genetic variants associated with a specific disease. Such risk scores enable stratification of individuals into low- and high-risk groups for common disorders such as heart disease, diabetes and most cancers.

$ 10M

$ 1M

$ 100K

$ 10K

Moore’s Law

$ 100M

$ 1K

200

2

2001

200

3

200

4

200

5

200

6

2007

200

8

200

9

2010

2011

2012

2013

2014

2015

Source: National Human Genome Research Institutehttps://www.genome.gov/sequencingcostsdata/

Individual genetic information will play an increasingly important role in healthcare.

Genetic tests will become particularly important in identifying and treating cancer and other serious diseases.

Creating Genetic Risk scores could aid insurance underwriting …

6 Swiss Re Risk Dialogue Series: Genomic medicine

In terms of insurance, GRS for breast cancer, for example, have been shown to have a better risk prediction than a score based on non-genetic risk factors (BMI, smoking status, alcohol, and family history of breast cancer) routinely assessed in insurance underwriting. Even better predictions can, however, be achieved using a combination of genetic and non-genetic factors. Along with traditional risk factors used in insurance underwriting, reliable GRS may become an additional or alternative technique for risk stratification of insurance applicants.

Insurers are supportive of the many advantages clinically relevant genetic testing has to offer in the prediction, prevention, diagnosis and treatment of disease, thereby increasing life expectancy or decreasing morbidity. It is currently common insurance best practice that applicants are not requested to undertake any genetic tests as part of the application procedure.

However, insurers are also concerned that individuals may not share existing reliable and risk-relevant genetic information from predictive genetic testing with them, thereby increasing insurers’ exposure to adverse-selection. The effects of adverse-selection are accentuated by ongoing legislative and regulatory processes in a number of countries restricting the request and use of genetic tests for underwriting purposes. Recent studies have shown that the financial impact of non-disclosure and/or restriction in access and use of existing predictive genetic information could be substantial to insurers. As a consequence, insurers may re-consider their underwriting, product design and pricing practices. Preserving the symmetry of information between insurers and applicants will be vital for the efficient operation of insurance markets.

Transgenerational epigenetic inheritance: A paradigm shift in biology and medicine

The contribution of Professor Isabelle Mansuy and Dr. Johannes Bohacek from the University of Zurich discusses the topic of epigenetics – the study of heritable changes in gene expression, which serve as an additional layer on top of genetics. Different epigenetic mechanisms have been shown to regulate the temporal and spatial control of genes, without changing the underlying genetic code. Such epigenetics changes can be inherited by future generations, although the detailed molecular mechanism of this inheritance are not fully understood. Notably, these mechanisms are responsive to environmental factors and play a fundamental role in the development and in health and disease. Geneticists believe that epigenetic alterations are as important as genetic mutations for the initiation and progression of progressive diseases such as cancer or diabetes. The increased understanding of epigenetic imprint mechanisms in disease manifestation holds great promise for developing prevention, detection, and therapy approaches.

Furthermore, epigenetic modifications have been used to develop an “epigenetic clock” to estimate the biological age of a cell, tissue or organ and holds the promise to predict “biological” age and life expectancy. This opens up the possibility of using epigenetic markers as a proxy for lifestyle or health status in medical and health risk assessment. Interestingly, GWG Life, a US based leader in the life insurance secondary market, recently announced that it is collecting and analysing epigenetic samples from life insurance policy owners, making it the first insurtech company to apply epigenetic technology to life insurance underwriting.

Liquid biopsy in oncology and implications for insurers

The articles from Professor Nicola Acteo, Professor of Oncology at University of Basel, and Christoph Nabholz, Head of Life & Health R&D and co-authors, provide us with insights into the emerging role of liquid biopsy in clinical practice and its potential implications for the insurance industry, respectively.

… however, insurers are restricted in their use of genetic tests.

Insurers are in turn wary of information asymmetries based on genetic tests.

Epigenetics may prove as significant to health as the underlying genetic fingerprint.

Epigenetics are further a good proxy for general health status, and are being used in insurance.

Introduction


Liquid biopsy is a minimally invasive technique that can identify molecular biomarkers in blood and other body fluids. Mainly used for cancer, liquid biopsies allow for detection and analysis of circulating tumour material (cells or DNA) shed into the blood from the primary tumour and from metastatic sites. Current clinical applications of liquid biopsy include patient stratification and therapy selection, monitoring treatment response and drug resistance, disease prognosis and detection of disease recurrence.

In addition, liquid biopsy is under current evaluation as a method to screen healthy individuals to detect cancer early, which is prior to clinical manifestation. Early detection is key to survival of most cancers, but more research is needed to establish the value of liquid biopsy as diagnostic screening test.

While liquid biopsy could ultimately benefit cancer patients and improve survival outcomes, it also creates new risks and exposures for life and health insurers. Widespread clinical acceptance and the premature use of liquid biopsy as a diagnostic screening tool enhances the risk of over-diagnosis – identifying a ‘disease’ that would never have caused symptoms or premature death. From experience, life insurers know that this can lead to controversial claims affecting multiple lines of business, especially critical illness products that do not have strong definitions and/or those that pay for earlier stage cancers. In addition, non-disclosure of relevant information from liquid biopsy tests could increase anti-selection risk for new critical illness, life, disability and medical reimbursement business. Hence, insurers will have to monitor closely the progress of liquid biopsy and developments in the field of early cancer detection, to manage these risks and to ensure their products remain sustainable and available to those who need them the most.

CRISPR – Hacking the biological hard drive

In the last article featured in this publication, Thomas Wildhaber, analyst at Swiss Re, and co-authors addresses the topic of gene editing. The term genetic engineering has been around for decades, but only in the past few years, researchers have developed the tools that allow them to edit the genome with the precision that they had originally envisaged. The discovery of CRISPR technology enables geneticists to edit parts of the genome by removing, adding or altering sections of the DNA sequence. The majority of proposed applications involve editing the genomes of somatic cells, where the effects of edits are limited to the tissue of an individual; but there is growing interest in and ethical debate about the potential to edit germline cells, where changes could be inherited by future generations.

The tool has a wide range of potential applications and in the future, may make it possible to correct mutations at precise locations in the human genome in order to prevent or treat genetic causes of disease. The recent FDA approval of Kymriah, the first gene therapy available in the United States to treat a form of childhood leukaemia, may mark the beginning of a new era using therapeutic genome editing for a range of diseases.

Alongside the risks and benefits of genome editing in healthcare, there are potential impacts to the re-/insurance industry as well. Uncontrolled release of gene-manipulated organisms into the environment or side effects from CRISPR based gene therapies, could lead to liability claims for suppliers of CRISPR tools and to the pharmaceutical industry, respectively. Widespread clinical adoption of the technology may create unexpected costs for the healthcare system. Finally, improving mortality and morbidity outcomes through CRISPR modified human stem cells, could significantly affect life, disability and longevity portfolios of insurance companies.

AuthorsDr. Florian Rechfeld, Senior Research Analyst L&H, Swiss ReDr Christoph Nabholz, Head R&D Life & Health, Swiss Re

Liquid biopsies detect cancerous cells or DNA in the blood …

… which can be used in disease screening …

… but carry the risk of over-diagnosis and adverse effects on insurers.

CRISR technology allows for accurate gene editing

… which is already being used to treat one type of cancer …

... although there is risk of side effects, particularly with the use of CRISPR at a population level.


Genomic medicine in clinical practiceVincent Mooser, Jacques Fellay

A major transformation in the way medicine will be practiced and health care provided is at our doorstep. Change will be driven by technological breakthroughs in information and nucleic acid sequencing technologies, and catalysed by massive investments around the globe. More specifically, it is anticipated that sequencing of our individual genomes will open up unprecedented opportunities to predict, prevent, diagnose and treat diseases. This will happen by integrating into medical practice the information pertaining to our innermost individual characteristics inherited from our parents. These account for most rare diseases and explain approximately half of the occurrence of common conditions. Major challenges need to be addressed for genomic medicine to deliver its full potential. Time will tell whether genomic medicine becomes a remarkable evolution, or a real revolution in health care.

Introduction

Breakthroughs in information and sequencing technologies make it now possible to sequence the 3.2 billion base pairs of an individual human genome for about USD 10001. This represents a decline in costs by five orders of magnitude since the sequence of the first human genome was published in 2001. The genetic makeup of individuals accounts for the occurrence of a large fraction of rare human diseases (defined in Europe as affecting less than one individual per 2000). It is estimated that there are more than 6000 rare diseases, that the majority of them (up to 80%) are due to single gene mutations and that, collectively, they affect up to one person in 10 in the population. Moreover, variation in our genome explains between 30 and 70% of common conditions (the remaining 70% to 30% being due to the environment) such as coronary artery disease, depression, or asthma. Accordingly, even if the question still remains open as to what will be the impact of genomic data on public health2, it is anticipated that access to genomic information will have a major impact on the way diseases are prevented, diagnosed and treated. Moreover, elucidating at the molecular level the roots of certain diseases should uncover new drug targets, which eventually will lead to innovative therapeutics. Some of these promises have already been fulfilled.

The major goals of this article are to review the current and upcoming applications of genomic medicine, to illustrate the challenges that need to be overcome to realise its full potential, and to describe some initiatives presently underway to capture the opportunities associated with these technological breakthroughs. For the sake of simplicity, genomic medicine will be defined here as the integration of genomic information into the practice of medicine. Genomic medicine is part of so-called precision, or personalised medicine. This article will focus on germline, that is inherited genomics, with limited references to somatic, cancer genomics.

Fifteen years after completion of the first human genome sequence, individual genome sequencing has become a commodity.

The information captured in an individual genome can be used to better predict, prevent, diagnose, and treat diseases.

Genomic medicine is defined here as the integration of individual genomic information into the practice of medicine.



Genomic medicine: Key facts

Number of letters (nucleotides) in the human genome

4 (A, C, T, G)

Size of the human genome 3.2 billion letters, corresponding to the size of 1000 bibles

Size of the coding portion of the human genome (exome)

40 million base pairs / 1.5% of the size of the genome

Portion of individual genome shared with reference genome

99.9%

Number of variants in individual genomes (compared to a reference genome)

4 million

Cumulative number of variants identified in 10000 genomes sequenced3

150 million

Costs of sequencing 1 human genome between 1990 and 2001

USD 2.5 B

Costs of sequencing 1 human genome in 2016 USD 1000

Number of PubMed hits while querying for – “Precision medicine” – “Personalized medicine” – “Genomic medicine” – “Pharmacogenomic”

Query on Jan 5th, 2017 (number of hits for years 2014–2016) – 11 230 (5 835) – 8 343 (4 604) – 5 941 (3 688) – 15 773 (3 469)

Number of genes in the human genome 20 000

Number of rare diseases due to a single gene defect 5000

Cumulative prevalence of patients affected by rare diseases in the population

10%

Number of highly penetrant clinically actionable genes4

59

Cumulative prevalence of carriers of highly penetrant clinically actionable mutations5

3.5%

Risk increase for coronary artery disease among quintile of the population with highest genetic score based on common variants, compared to lowest quintile6

1.9 (90% increase)

Number of drugs with pharmacogenetic/genomic in FDA label*

170

Number of pharmacogenomic applications with proven clinical utility (outside oncology)⁷

2

* http://www.fda.gov/drugs/scienceresearch/researchareas/pharmacogenetics/ucm083378.htm


The basics of genomic medicine

The human genome consists of DNA and is contained within chromosomes, which are located within the cell nucleus. The building blocks of DNA are nucleotides, of which there are four (A, C, T and G). These four letters represent the alphabet of the human genome. Half of our genetic material comes from our mother, half from our father. Only a small fraction of the human genome codes for protein (1.5% of the genome, corresponding to 40 million base pairs distributed in 20,000 genes); the remaining 98.5% is called non-coding DNA. The precise sequence of A, C, T and Gs along the chromosomes determines the quality, abundance, the timely and local expression of gene products, ie proteins.

Tens of thousands of human genomes have been sequenced so far3. Comparison of individual genomes indicates that 99.9% of our genome is shared with other individuals. The remaining 0.1% difference is mostly accounted for by the presence of single nucleotide polymorphisms (SNPs, like a T substituted for an A in a certain position) spread over the entire genome, by duplications or deletions of small portions of the genome, or by rare structural abnormalities. This 0.1% difference, which totals approximately 4 million variants (including 3.5 million SNPs), ensures our uniqueness. It also explains in part our individual susceptibility to diseases and the way we respond to particular environmental agents, including drugs and pathogens. Variants can be characterised by their chromosomal position, their location within coding or non-coding regions of the genome, their frequency (from very rare to common in the population) and their functional impact on the gene product. The vast majority of variants are rare or very rare (present in less than 1 in 1000 individuals), and a fraction of these tend to be functional. In contrast, common SNPs tend to be in non-coding regions of the genome and are less likely to have any functional impact3,8.

To illustrate the former case, SNPs within the gene encoding of an ion channel called CFTR may destroy the function of this protein. If both the paternal and maternal copies of this gene are non-functional, absence of CFTR leads to cystic fibrosis. Until recently, detection of these SNPs was performed using a technology called Sanger sequencing, which made it possible to analyse a limited set of genes in a restricted number of individuals. The development of next generation sequencing (NGS) technologies makes it now possible to sequence large portions of the genome (like the exome, corresponding to the coding genome) or the entire genome in a cost-effective manner.

The human genome contains 3.2 billion base pairs, each base pair corresponding to one letter of a 4-letter alphabet.

Individual genomes only differ by 0.1%. This 0.1% difference explains in part our individual specificities, our susceptibility to diseases and response to therapies.

Single nucleotide polymorphisms (SPNs) represent the major source of inter-individual variation in the human genome. Compared to a reference genome, each genome contains approximately 3.5 million SNPs



The applications of genomic medicine

There is no doubt that, in the long run, genomic medicine will have a broad impact on the healthcare system. The key questions today are: Which areas of medicine will benefit first? What are the challenges overcome for individuals to benefit from these advances? How can individuals be protected from potential risks associated with genomic information? Which investments will most effectively contribute to our knowledge and which will serve as the foundation on which genomic medicine will be built?

In a nutshell, the elucidation of our germline and inherited genome should improve our ability to diagnose mostly rare and some common diseases, improve prediction and prevention of rare and common diseases, anticipate drug response and tailor therapies to the individual characteristics of patients. This latter point is particularly relevant to oncology, where sequencing of the tumor genome is already part of clinical practice.

Improvement in diagnosisDiagnosis of diseases can turn into a major challenge, and this may be particularly true for certain rare conditions, which have a variety of clinical expressions (this is referred to as clinical pleiotropy or heterogeneity). Similarly, the same clinical condition may be due to mutations within different genes (this is referred to as genetic heterogeneity). The possibility to molecularly define the cause of a particular disease through DNA sequencing can lead to optimisation of medical care, better counseling and, at term, targeted gene therapy using novel gene-editing technologies like CRISPR. This is especially relevant for rare pediatric diseases, where patients and their parents sometimes go through a lengthy and painful ‘therapeutic odyssey’ until a proper diagnosis is set. Today, exome and genome sequencing are making their way into routine diagnosis for rare monogenic conditions9, including complex metabolic disorders associated with mental retardation10.

In the same vein, sequencing panels of genes known to predispose carriers of pathogenic mutations to certain diseases may be of great help for the patients and their relatives. An example to illustrate this point is sudden cardiac death. A substantial fraction of sudden cardiac death is accounted for by mutations within genes known to be involved in heart rhythm11. These mutations may go unnoticed until the carrier puts the heart under sudden pressure, or is exposed to drugs, which are known to alter the heart electrical system. Carriers may then experience cardiac arrest and death. Identification of susceptible individuals before this happens may help prevent sudden death. Sequencing may be used to elucidate, post-mortem, the molecular cause of sudden death, in an attempt to protect relatives that may carry the same pathogenic mutations. A proof-of-concept for this type of molecular autopsy has recently been published12.

In the long-run, genomic information will impact all fields of medicine

Genomic medicine will mostly initially impact, rare diseases, pharmacogenetics and cancer.

New sequencing technologies will accelerate the journey to diagnosis for rare, complex diseases and reduce time wasting, pain and unnecessary therapeutic treatments.

Sequencing may elucidate, post-mortem, the cause of sudden death. This type of molecular autopsy can be used to alert relatives of preventative measures.


Predictive and preventive medicineSequencing of the genome (or interrogation of numerous SNPs by genotyping) makes it now possible to better anticipate the risk of certain diseases and, for those that are clinically actionable, to take appropriate preventative measures.

The risk of developing a disease due to genetic variants within a single gene (ie monogenic conditions like cystic fibrosis or familial forms of breast cancer) or multiple genes (for polygenic, complex diseases like Type 2 diabetes or coronary artery disease) is called penetrance. The population-attributable risk is determined by the frequency of the variants and their penetrance. As an illustration, mutations within the BRCA1 gene are associated with a 50%–70% risk of developing breast cancer, but are only present in 0.5% of the general population, thus accounting for only a small fraction of all cases of breast cancer. For coronary artery disease, genetic scores have been constructed, based on the presence or absence of multiple predisposing variants throughout the genome. Recently, it was shown, based on more than 56,000 individuals followed prospectively, that individuals within the top quintile score (ie 20% of the population with the highest genetic score) have, compared to the ones in the lowest quartile, a 91% increased risk of coronary artery disease, which is similar in amplitude to the impact of poor lifestyle6.

Tailored therapyPharmacogenetics is a particular application of genomic medicine, where specific variants within genes encoding for proteins implicated in drug absorption, distribution, metabolism or elimination or in the occurrence of particular adverse side-effects13 are analysed before a drug is administered14. Genetic information has been shown to be helpful (but utility has not been necessarily proven7) for more than one hundred drugs. Analysis of a set of pharmacogenetic markers is now part of routine care in certain hospitals.

Genome-guided adaptation of treatment is of particular interest in the field of oncology. Sequencing of the tumour genome, which is now part of the therapeutic armamentarium, allows the molecular definition of the tumour DNA and dictates which treatment should be prescribed to which patient. This molecular analysis can be performed on biopsies, on material resected during surgery, but also on free circulating small fragments of DNA released by the tumour into the blood stream (ie liquid biopsies).

New drugsIt is anticipated that elucidation at the molecular level of the roots of diseases should lead to new drug targets and, consequently, innovative therapeutics. A paradigmatic example to illustrate the power of genomics in drug target identification is PCSK9 inhibitors15. PCSK9 was identified as a gene associated with low cholesterol levels. Loss of function in this gene was also associated with a lesser risk of heart attack, but no other phenotypes. These observations provided sufficient information for pharmaceutical industry to develop PCSK9 inhibitors, with the prospect that such drugs would reduce the risk of heart disease and, in absence of off-target effect, would be safe. This prediction happened to be true, and PCSK9 inhibitors have recently been approved by the FDA and other regulatory agencies for treatment of elevated plasma levels of LDL-cholesterol and for prevention of heart attacks. Today, genetic information is highly valued, or even requested, for target validation in pharma16.

Genomic analyses can reveal a particular susceptibility to familial diseases like breast cancer, or common conditions like coronary artery disease.

Pharmacogenetics uses individual genetic markers to minimize the risk of adverse effects and to optimise the response to therapies.

Analysis of tumour genome points to optimal treatment.

Genomics can be used to identify novel drug targets.



The challenges associated with genomic medicine

The road to a genomic medicine application is complex and numerous challenges need to be addressed before genomic medicine realises its full potential. These challenges pertain to biology, medicine, bioinformatics and computer sciences, but also to ethics, law and economics.

A particular, frequently underestimated, challenge is the demonstration of clinical utility of a genomic medicine application. With advances in, and commoditisation of, sequencing technologies, generating huge amounts of genomic data has become cheap and easy. It is relatively simple and inexpensive to identify an association between a particular genetic marker and a medical condition. To transform this data into knowledge, and then into clinical utility, requires massive investments to cross what some people call ‘death valley’. The example of abacavir, an anti-HIV drug, illustrates this point. Abacavir causes a hypersensitivity reaction in about 3% of exposed HIV patients. It took only a couple of years to show that this adverse reaction was genetically associated with an immunity marker located in the HLA region on chromosome6. However, a large, randomised, prospective, double-blind trial involving almost 2000 patients was then required to show that, from a medical perspective, it makes sense to analyse this marker before the drug is prescribed so as to exclude carriers from exposure. The trial demonstrated that the number-needed-to-test to prevent one event was 3717. This made it a very acceptable proposition and FDA has incorporated this pharmacogenetic test into the drug label. The massive hurdles necessary to demonstrate clinical utility will require some significant changes in regulatory practices and innovative approaches beyond clinical trials.

Another particular challenge pertains to variants of unknown significance. As mentioned above, each of us carries, compared to a reference genome, millions of variants. Whether they are clinically relevant is not known for the vast majority of rare variants. The annotation of specific variants requires, beyond a dedicated bioinformatics infrastructure, access to very large databases and cohorts with high-quality clinical data. This allows a sufficiently large number of carriers to be analysed together, for example in phenome-wide association studies18, and to derive meaningful conclusions. This is the pre-requisite for a proper interpretation of genomic data and the implementation of appropriate measures.

A particular aspect of genomic medicine pertains to data and privacy protection 19. In contrast to most other medical information contained in medical records, leakage of genomic information is irreversible. It may provide some important clues about future events, and not only impacts an individual, but also his or her relatives, who share part of their genome with him/her (50% for first-degree relatives, ie siblings or children). Accordingly, significant effort needs to be dedicated to protect this type of data. Modern, state-of-the-art methods, in particular homomorphic encryption, are being developed to address this issue 20, but a solid legal framework is also required to avoid abuses and discrimination based on genomic information.

Many hurdles need to be overcome to deliver a clinically useful genomic medicine application.

Demonstration of clinical utility for a genomic medicine application frequently requires massive investments and proper clinical trials.

Demonstration of the clinical effect of most SNPs, and proper interpretation of genomic information, require access to very large cohorts and/or databases.

New technologies are being developed to protect genomic information.


These biomedical and data protection questions do not underestimate the ethical, legal and societal issues related to genomic medicine, as well as the health economics aspects.

As an example, once the clinical utility of a particular genomic medicine application has been demonstrated, returning the genomic information to individuals raises per se a series of questions, which need to be addressed carefully. Little progress has been made in establishing best practice for the return this type of information. The American College of Medical Genetics has established a list of 59 genes, mostly involving genes implicated in inherited cancer and cardiovascular diseases, which deserve to be communicated in case of incidental findings4,21. Recently, exome sequencing of more than 50,000 people has shown that 3.5% of these individuals are carriers of such actionable mutations 5, and the benefits of detecting highly penetrant disease predisposing mutations could be particularly important for a condition called familial hypercholesterolemia 22.

Finally, a large push is needed in terms of education in genomic medicine and its peculiarities, in particular its probabilistic nature. This should not only target health care providers, but also the general population and specific groups of stakeholders (lawyers, politicians, etc.).

To successfully develop genomic medicine, and have the population benefit from it, requires a series of ingredients, which can be illustrated in the virtuous cycle on the opposite page. Critical for any publicity drive in genomic medicine is the engagement of the population, volunteers and citizens. These individuals must properly consent for the use of their biomedical data (or other related data which can be derived from ‘quantified self’ instruments) and biological samples (in particular those used for extraction and analysis of germline DNA, but also any other samples which can benefit from other genomic or personalised analyses), which need to be stored in appropriate conditions. This type of bioresource constitutes the foundation of any research in genomic medicine. Access to high-quality sequencing laboratory, to strong bioinformatics capabilities, robust IT infrastructures and a clinical research centre for detailed clinical characterisation of cohort participants are essential ingredients for the second quadrant. Once a genomic medicine application has been demonstrated to be clinically useful, a dedicated, multidisciplinary genomic medicine clinic needs to be put in place, to serve the patients, cohort participants and their relatives. Finally, for the population to benefit from these investments and to close this virtuous cycle requires a strong societal engagement, well-delineated governance, a robust legal and ethical framework, and proper training of healthcare professionals.

Several public and private initiatives have been launched in various countries to capture the opportunities associated with genomic medicine. The Precision Medicine Initiative (PMI) in the US is particularly illustrative of the scale of necessary investments for genomic / precision medicine to be delivered. This USD 213 million programme will invest more than USD 100 million to develop a 1-million volunteer cohort followed prospectively, with a specific interest on oncology and rare diseases 23.

Genomic medicine raises major ethical, legal and societal issues, which need to be addressed holistically.

The optimal way to return genomic information and incidental findings needs to be defined.

There is a major need to educate healthcare professionals and the society at large about the benefits and risks of genomic medicine.

The ingredients necessary for the population to benefit from genomic medicine are illustrated in a virtuous cycle.

Massive investments are being made around the globe to capture the opportunities associated with genomic medicine.



Individual | Population

Governance, citizen sciences

Genomic medicine clinic

Clinical research

Bio-resource

Pre-analytical lab

Bioinformatic and sequencing

Biobanks

Consent

Clinical dataGovernance and ethics

Societal engagement

Next generation of health care

professionals

Competencies and training

Relatives and family

Multidisciplinary approach

Councelling

Clinical utility

Research projects

Clinical research

center

Figure 1: The virtuous cycle of genomic/precision medicine. Described here are the ingredients and the sequence of events necessary for a genomic/precision medicine application to benefit the patients or the population. Strong engagement from the population, patients or volunteers (at the top of the circle) is critical for the construction of an appropriate bio-resource (dark blue quadrant), which will “feed” the technology platforms (IT, sequencing, *omic) and the research projects to identify new applications, test them and demonstrate their clinical utility (red quadrant). For the cycle to be closed, i.e. the population or patients to benefit from these investments requires a dedicated clinic (light blue quadrant), with the whole process embedded within a strong governance, regulatory environment and appropriate citizen sciences and training of healthcare professionals and the society (green quadrant).

In the UK, the Genomics England 100,000 Genomes Project is underway 24, while China also is investing massively in precision medicine 25. In Switzerland, the Swiss Personalized Health Network (SPHN) has been put in place to position the country as a key player in precision medicine. A particular initiative in Western Switzerland, which parallels and completes a population-based cohort of 6000 extensively phenotyped, genome-wide genotyped individuals called CoLaus 26, is the Lausanne Institutional Biobank, specifically designed to participate in the construction of the knowledge needed for precision medicine, and for its implementation locally 27, 28.


In parallel, substantial investments by the pharmaceutical industry, insurance companies and direct-to-consumer genetic companies are being made. Those organisations will have access to large bodies of clinical and associated genomic data, which will give them a competitive edge in genomic medicine. They could, for example, charge significant amounts of money for proper interpretation of genomic data, or use genomic information on large cohorts to perform early-phase, proof-of-concept clinical trials in a restricted number of highly selected individuals who have the highest chance to respond to an investigational drug.

Summary and conclusions

Commoditisation of individual genome sequencing will lead to major changes in the way medicine is practiced and health care provided. Whether this will be a major evolution or a revolution, remains to be seen. Major investments are needed to realise the full potential of genomic medicine, and a variety of risks need to be addressed in a holistic manner. It is not unrealistic to anticipate that, within a decade, the genome sequence will be part of everyone’s medical record, allowing for a more precise and more personal practice of medicine.

Private pharma, insurance or IT companies are investing to become key players in the field.

Time will tell whether genomic medicine is an evolution or a revolution in healthcare.



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AuthorsVincent Mooser MD is professor of Medicine and head of the Lab Department at Lausanne, Switzerland, CHUV University Hospital. Before taking this position in 2011, he was vice-president in charge of applied genetics at GlaxoSmithKline, based in Philadelphia. He was the co-principal investigator of the Lausanne-based CoLaus cohort, and is the principal investigator of the Lausanne Institutional Biobank. He chairs the executive board of the Swiss Biobanking Platform and is a committee member of the Swiss Academy of Medical Sciences.

Jacques Fellay MD PhD is head of the Precision Medicine Unit at the CHUV University Hospital in Lausanne, Switzerland. He is also an assistant professor of Human Genetics at the EPFL School of Life Sciences and a group leader at the Swiss Institute of Bioinformatics.

The authors thank their colleagues in the CHUV/UNIL Genomic Medicine Working Group for constructive discussions and for their engagement: Murielle Bochud, Jacques Cornuz, Idriss Guessous, Zoltan Kutalik, Anièle Lecoq, Nicolas Rosat and Gérard Waeber.


Transgenerational epigenetic inheritance: A paradigm shift in biology and medicineJohannes Bohacek, Isabelle M Mansuy

One of the most remarkable breakthroughs of the 20th century was the discovery of genetics and DNA. Building on the ground-breaking work of Charles Darwin and Gregor Mendel, the discovery of DNA unfolded in several steps starting with the first description of nucleic acid by Friedrich Miescher and of the DNA double helix by Rosalind Franklin, James Watson and Francis Crick. Since then, genetics has dominated biology, and the advent of DNA sequencing in the 1990s further revolutionised the field. Genetics culminated in the human genome project, one of the largest research projects of the last 100 years, which revealed the first human genome sequence and dramatically moved biology and medicine forward.

Decrypting the DNA sequence was expected to reveal the secrets of life and help understand the mechanisms of complex diseases. It was hoped to lead to the identification of genes responsible for diseases that run in families and thus presumed to have a strong genetic basis, and ultimately the treatment of diseases. However, in the 15 years after the first human sequence was determined, no clear genetic basis has been found for most heritable diseases. This was despite enormous improvements in sequencing technology and significant research investments to examine disease genetics (Manolio et al., 2009; Petronis, 2010). Researchers were further dumbstruck by new mysteries revealed by genetic sequencing: Why do only a few percent of genes for proteins code, while the rest is non-coding? And why do the relatively small number of protein coding genes identified – around 20–25,000 and with remarkable homogeneity across the animal kingdom – provide so little information about the structure, function and fate of cells, even less so for complex multicellular organisms?

The (re)emergence of epigenetics

Naturalists, biologists and clinicians have over the past two centuries observed that the environment strongly influences individuals and cells. However, this was formally put into a biological framework only in the 1940s by the British biologist Conrad Waddington who, inspired by the seminal work of the French naturalist Jean-Baptiste de Lamarck in the 18th century, introduced the notion of an epigenetic landscape. This concept illustrated how different cellular fates can be determined depending on choices driven by the environment. These choices guide development by modulating the way genes are regulated and expressed, and idea that is now captured by the burgeoning field of epigenetics (Allis and Jenuwein, 2016).

Today, we understand epigenetics as a discipline that relates to the study of the way the genome is regulated in a potentially heritable manner. Epigenetic mechanisms are processes that activate or silence gene expression by remodeling chromatin. Chromatin comprises the DNA helix which wraps around octamers of histone proteins to form nucleosomes. It can be structurally remodelled by covalent modification of the DNA and histone proteins, in particular DNA methylation (DNAme), and histone posttranslational modifications (HPTMs). The ensemble of these modifications constitutes an epigenetic code that alters the activity of the genome without changing the DNA sequence itself (Allis and Jenuwein, 2016). In mammals, DNAme is a biochemical process that involves the covalent addition of a methyl group (CH3) to cytosines in DNA, preferentially onto CpG (cytosine-guanine) dinucleotides. HPTMs are also covalent modifications that occur on protein histones in specific combinations and include, amongst others, acetylation, phosphorylation, methylation and many others. The ensemble of modifications composed of DNAme and HPTMs establishes an epigenetic profile that is dynamically regulated at each individual genomic sequence. These marks modify the local electrochemical properties of chromatin, altering its conformation and thereby regulating the accessibility of genes to the transcriptional machinery. Ultimately, this modifies gene transcription in a spatially- and temporally-regulated manner in response to specific internal and external cues (Allis and Jenuwein, 2016). Further to DNAme and HPTMs, increasing evidence has pointed to the importance of non-coding RNAs (ncRNAs) as an additional means of gene regulation. NcRNAs exist in a diverse range

Genetics has long dominated biology, but it is now clear that the genetic code is not the end of the story, but just the beginning.

Genes represent only a small portion of the genome and whole genome sequencing has raised many unexpected questions.

Epigenetics is a novel discipline that capitalises on historical observations and which has gained major importance in the post-genomic era.

Epigenetics is an ensemble of complex mechanisms that control the genome and its activity in individual cells in organisms.



of size, and unlike messenger RNA (mRNA), are not translated into proteins (although some can be) but act to regulate gene expression. They can induce mRNA degradation and interfere with protein translation, or they can act as guides, directing components of the epigenetic machinery to specific DNA sequences.

Genetics and epigenetics are so closely linked, that a popular computer view compares genes to the hardware of a computer, and epigenetics to the software, which instructs the hardware on how to execute complex tasks. Epigenetic mechanisms are at the interface between environment and the genetic makeup of an organism, and play a fundamental role in development, health and disease. Environmental influences can induce changes, so called epimodifications, in the epigenetic code, which can impact cellular functions. Intriguingly, epigenetic mechanisms operate in all somatic cells, but also in germ cells (oocytes and sperm cells, Figure 1), the very cells which give rise to the next generation (Bohacek and Mansuy, 2015). This opens the possibility that environmental factors that induce epimodifications in germ cells can lead to heritable changes that can be passed from parent to offspring.

Genetics can no longer be considered without epigenetics.

Figure 1: Major epigenetic marks in mammalian germ cells. Mature sperm cells and oocytes carry multiple epigenetic marks including DNA methylation, post-translational modifications on histones and protamines and non-coding RNAs. Environmentally-induced changes of these epigenetic marks (epimodifications) are implicated in transgenerational transmission of acquired traits. © Nature Genetics Reviews (Bohacek and Mansuy, 2015).


Indeed, evidence has accumulated in humans and animal models, suggesting that the environment can also impact epigenetic mechanisms in the germline, and affect the transmission of acquired changes from parent to offspring. In a mouse model, diet was shown to influence coat colour across generations. A diet rich in methyl administered during gestation was observed to alter the activity of an agouti allele and shift coat colour from yellow to agouti in the offspring, and this persisted across multiple generations (Morgan et al., 1999). Further in a rat model, a chemical was shown to have transgenerational effects. In gestating females, injection of the fungicide vinclozolin, a compound that acts as an endocrine disruptor, altered reproductive functions and induced tumours and kidney diseases across multiple generations (Anway et al., 2005). The most striking property of these effects was that they affected all the progeny and did not segregate in a Mendelian way as expected by classical genetics. Thus, it is now believed that epigenetic inheritance, the transmission of acquired epigenetic information from parent to offspring, can contribute to the inheritance of disease and explain, why some disorders run in families, without a clear genetic cause (Bohacek and Mansuy, 2015).

Epigenetic inheritance and the brain: Pioneering research for psychiatry

Psychiatric conditions are among the most complex diseases in humans. Many psychiatric diseases including, personality disorders, major depression or bipolar disorder, have a strong heritable component. These diseases have also been known to be related to the exposure to detrimental environmental conditions for a long time. Traumatic experiences and chronic stress are recognised as major risk factors for emotional, cognitive and mood disorders across families in humans, particularly if the adversity is experienced early in life. Despite numerous genome-association studies, the genes underlying these diseases could not be identified until now (Eichler et al., 2010; Manolio et al., 2009), and the suspicion that epigenetic factors could be involved had started to emerge. In the early 2000, when our lab became interested in the question of whether environmental exposure and personal experiences such as early life trauma could indeed become transgenerational risk factors for disease, there was virtually no scientific data available to support this idea.

Inspired by clinical observations of the long-lasting negative impact of traumatic experiences early in life, we developed a mouse model of early trauma that displays heritable symptoms across generations. This animal model mimics childhood maltreatment and disrupted social relationships in early postnatal life by exposing new-born mouse pups to chronic and unpredictable maternal separation combined with unpredictable maternal stress (MSUS). Mice subjected to such trauma display behaviours reminiscent of human depression, antisocial behaviours, higher risk-taking, cognitive impairment, and also have altered metabolism (Bohacek et al., 2015; Franklin et al., 2010, 2011, Gapp et al., 2014a, 2014b; Weiss et al., 2011). These symptoms are similar to those often observed in psychiatric patients with a history of childhood trauma.

Epigenetics can explain how environmental exposures and lifetime experiences can be inherited, and offers a radically new view on heredity. This view is a paradigm shift in biology that questions genetics, one of its major cornerstones.

Psychiatry is one of the branches of medicine that can benefit the most from epigenetics. It is envisioned to be transformed by epigenetics.

To study if epigenetic factors are responsible for the expression and the transmission of the impact of traumatic experiences in early life, an experimental mouse model was developed in the laboratory. Today, this unique model of early trauma is the most valid and robust in the field.



Further, these behavioural symptoms are transmitted across several generations by both female and male parents, and are associated with neurochemical alterations that are often seen in psychiatric patients (Franklin et al., 2011; Razoux et al., 2016; Weiss et al., 2011). We have used several strategies such as breeding through males, in vitro fertilisation and cross-fostering to confirm that transmission depends on the germline and is independent of maternal care. With this confirmation, the resulting mouse model is one the most solid models of transgenerational inheritance in mice, and the first developed to mimic human psychiatric diseases. The notion that environmentally-acquired traits (and their associated epigenetic marks) can become risk factors for disease that can be passed transgenerationally from parent to offspring and grand offspring is summarised in Figure 2, panel C. At the same time, this figure also shows that not all environmental exposures induce heritable changes in germ cells (Figure 2, panel A), and that some changes can be passed from parent to offspring, but do not impact the grand offspring and subsequent generations (Figure 2, panel B).

After it was clear that transmission of behavioural and physiological alterations induced by trauma indeed occurs through the germline in mice, we asked which epigenetic mechanisms are involved in this form of inheritance. Initially, we looked at DNAme in the brain and germ cells, and found that some genes are hypomethylated, while others are hypermethylated across generations in adult animals subjected to trauma during early postnatal life (Bohacek et al., 2015; Franklin et al., 2010; Gapp et al., 2016). We also showed that HPTMs are affected in the brain of traumatised animals and their offspring (Gapp et al., 2014a). Ultimately, we discovered a key role for ncRNAs, novel genome regulators, in transgenerational epigenetic inheritance. Several microRNAs and piwiRNAs were found to be dysregulated in sperm cells, and some were also affected in the brain and blood serum (Gapp et al., 2014a). We then went even further and tested whether sperm RNAs are causally linked to epigenetic inheritance. A key experiment was conducted that consisted in extracting RNAs from the sperm of control and traumatised males, injecting these RNAs into fertilized eggs then transplanting the injected eggs into recipient mothers. The animals resulting from sperm RNAs-injected eggs were then tested when adult, and the males were further bred to control females to generate an offspring. Strikingly, these animals and their offspring had pathological behaviours that were similar to those expressed by animals directly exposed to trauma. They had almost identical behavioural alterations as naturally conceived offspring of stressed males, and also had a similarly altered metabolism (Gapp et al., 2014a). These results were the first to provide direct causal proof for the implication of sperm RNAs in the inheritance of symptoms induced by trauma.

The mouse model reproduces the heredity of symptoms observed in humans.

The transmission of symptoms induced by early traumatic experiences involves germ cells and epigenetic mechanisms in these cells.


One of the difficult challenges in this field is to select specific tissues for molecular analyses in parent and offspring, because inherited epigenetic changes can potentially manifest themselves in any tissue, and the mechanisms guiding tissue specificity are unknown. Further, it remains unclear in which reproductive cells epigenetic changes can be installed, particularly in males where continuously renewing germ cells generate new sperm cells throughout life (Bohacek and Mansuy, 2015). In Figure 3, we provide an overview of the male reproductive system to show that environmental factors like stress, diet, exercise or pollution could impact germ cells at many stages of development. Our model of early life traumatic stress (MSUS) induces lifelong changes in the germline that can be transmitted to the offspring, thus suggesting that early stem cell populations that give rise to sperm cells throughout life (spermatogonial stem cells) are likely targeted by the traumatic event. However, permanent alterations in blood, fat or in the testicular tissue surrounding the developing sperm cells could also explain the lifelong impact.

Identifying all the mechanisms responsible for transmission to the progeny is a large and challenging endeavour, and one of the most important research goals in the field.

Figure 2: Exposure to environmental factors (eg traumatic life events) can induce different types of epigenetic changes in germ cells. These changes may or may not be transferred to the offspring or the grand offspring. (A) Germline epigenetic marks, in particular when involving DNAme, histone variants and histone modifications, may not be transferred because of correction/erasure by epigenetic reprogramming before or after fertilisation (Feng et al., 2010; Seisenberger et al., 2012). (B) Germline epimodifications may escape or resist reprogramming, and exert an effect on the offspring’s somatic cells but not its germ cells. This constitutes intergenerational epigenetic inheritance, because the grand offspring is not affected. (C) If epimodifications resist reprogramming and are maintained in the germline across subsequent generations, it constitutes germline transgenerational epigenetic inheritance. The distinction between inter- and transgenerational is very important and implies key differences in the location, persistence and underlying mechanisms of the induced changes. Firmly distinguishing between these two modes of inheritance requires the testing of at least the grand offspring of exposed individuals (Jirtle and Skinner, 2007). Figure copied from (Bohacek and Mansuy, 2017).


Figure 3: Male germ cell development and spermatogenesis in mice. Male germ cell development begins prenatally and continues throughout life in the testes. Epigenetic modifications involved in germline epigenetic inheritance can be studied in mature sperm cells that are stored for release in the cauda epididymis (A). Epigenetic modifications can already be induced and detected during early developmental stages, affecting primordial germ cells (PGCs, B) and/or spermatogonial stem cells (SSCs, C). Environmental factors can also impact Sertoli cells (D) or the epididymal duct (E), thus potentially affecting developing sperm cells upon transit through these structures. SPCs = spermatocytes; PL=Pre-leptotene; P=Pachytene.Figure copied from (Bohacek and Mansuy, 2017).



AcknowledgmentsThe Mansuy lab is supported by the University Zürich, the ETH Zürich, the Swiss National Science Foundation, Novartis, Roche, a Forschungskredit of the University of Zurich (grant no. FK-15-035), the Vontobel Foundation, the Betty and David Koetser Foundation for Brain Research, the EMDO Foundation and the Olga Mayenfisch Foundation, and a private donor.

Summary and outlook

The concept that epigenetic mechanisms underlie complex brain functions and behaviour, and the development of psychiatric conditions and their transmission across generations is a ground-breaking concept in biology and medicine (Bohacek and Mansuy, 2015, 2017). It provides a new framework to the unresolved question of the genetic versus environmental origin of brain functions, and brain disorders and their missing heritability (the fact that many diseases are due to environmental factors and not to a genetic mutation). The novelty of the work lies in the assessment of several epigenetic mechanisms and their parallel analyses in germ cells, brain and blood in mice across generations. Such multi-tissue and cross-species analyses have not been done before and offer an extremely powerful and unprecedented means to efficiently and decisively determine the relevance of these mechanisms to brain functions and their pathologies. Future research will need to address three major challenges: 1) Identify specific germline epimodifications that are causally responsible for the transfer of information to the offspring. To gain such causal evidence, recent technological advances in (epi)genome editing offer the exciting possibility of manipulating epimodifications, and test their functional involvement in the transmission of traits across generations (Chapman et al., 2015; Hilton et al., 2015). 2) Identify the mechanisms by which environmental factors can install and maintain epimodifications in germ cells. This will require studying multiple tissues and testing different possible links between these tissues and developing germ cells. 3) Determine the contribution of genetic factors to epigenetic inheritance by delineating the interaction between genetic mutations and epimodifications. This will require high-throughput genomic methodologies to screen and identify genetic features, and integrate complex genomic and epigenomic datasets (Gemma et al., 2013). Recent work has revealed the potential of this approach by demonstrating that diet-induced changes in DNAme can depend on a single nucleotide variant in ribosomal DNA (Holland et al., 2016). Our own lab has recently initiated parallel analyses in human cohorts exposed to various types of trauma including childhood trauma, war trauma, based on a collaborative effort with clinicians in Switzerland, Europe and USA. Such preclinical and clinical research is revolutionising the field of biology and medicine, and is expected to provide novel and unprecedented perspectives for therapeutic approaches in the future. The results of this research are extremely important to better understand the impact of the environment on human beings and the consequences for the society, not only in terms of mental and physical health but also in terms of its social determinants across generations.

Transgenerational epigenetic inheritance is a ground-breaking and highly innovative field of research that has many challenges; but also holds great promises for better mental and physical health in the future.



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AuthorsIsabelle Mansuy is professor in neuroepigenetics at the Medical Faculty of the University Zürich and the Department of Health Science and Technology (D-HEST) of the Swiss Federal Institute of Technology Zürich (ETHZ). She obtained a PhD in developmental neurobiology at the Université Louis Pasteur Strasbourg, France then trained as a postdoctoral fellow at Columbia University, New York before establishing her lab at ETHZ in Dec 1998. Her research examines the epigenetic basis of complex brain functions and the heritability of acquired traits across generations in mammals. It focuses on the mechanisms underlying the expression and the inheritance of the effects of environmental factors such as traumatic stress in early life, on behaviour and physiology, and their link with diseases in humans. The major goals are to gain new knowledge into the ensemble of epigenetic mechanisms including DNA methylation, non-coding RNAs and histone modifications that are persistently altered by early experiences and how they are transmitted across generations. This research is based on mouse models and on translation to humans. Isabelle Mansuy co-authored many research articles, reviews and books in the field of neuroepigenetics. She is member of the Swiss Academy of Medical Science, the Research Council of the Swiss National Science Foundation, and European Molecular Biology Organization. She is recipient of the Medal of Chevalier dans l’Ordre National du Mérite and of the Medal of Chevalier de la Légion d’Honneur in France.

Johannes Bohacek is assistant professor at the Department of Heath Sciences and Technology of the ETH Zurich. He studied psychology in Austria, completed a Master’s degree in Applied Biopsychology at the University of New Orleans, and a PhD in Neuroscience from Tulane University in the lab of Prof. Jill Daniel in 2009. He conducted his postdoctoral training with Prof. Isabelle Mansuy. His research focuses on the organism-wide consequences of stress, how the complex stress-response leads to changes in behaviour and increases the risk for neuropsychiatric disease. His research uses mice as a model organism to study the molecular changes underlying stress-induced anxiety, and how stress can epigenetically impact the germline.


Liquid biopsy in oncologyNicola Aceto

The advent of liquid biopsies and their potential to revolutionise cancer care is causing great excitement among oncologists. The term “liquid biopsy” refers to the analysis of circulating tumour cells (CTCs) and tumour-derived circulating DNA (ctDNA) from the blood of cancer patients as well as healthy individuals. CTCs have proven highly promising for stratifying cancer patients as responders or non-responders prior to therapy; as well as for individualised testing of metastatic drug susceptibility. As two sides of the same coin, ctDNA is likely to feature as a companion diagnostic to assess eligibility to a specific drug; as a means of monitoring minimal residual disease in patients at risk of recurrence; and potentially, as a method to screen healthy individuals to detect cancer prior to clinical manifestation. Following studies, both CTCs and ctDNA, are now clinically used in a limited number of hospitals and cancer centres; However, much research remains to be undertaken before their widespread use in cancer-related healthcare. As major trials seek to resolve open questions, liquid biopsies through the analysis of CTCs and ctDNA holds great potential for cancer sufferers.

Introduction

Currently, cancer is among the leading causes of death, with more than 14 million new cases and 8 million cancer-related deaths per year worldwide (www.cancer.gov). Further, the number of new cases is expected to rise to 22 million within the next two decades. Clearly, these numbers reflect our limited understanding of how to treat cancer successfully and prevent mortality due to this disease.

The term “liquid biopsy” refers to obtaining a sample from peripheral blood (and in some cases, other body fluids such as saliva, urine or cerebrospinal fluid) with the goal to identify circulating tumour cells (CTCs) or fragments of circulating tumour DNA (ctDNA) released by tumour cells from anywhere in the body 1 (Figure 1). Recently, this term has received extraordinary attention because of its potential to revolutionise treatment decisions, disease monitoring, and early cancer detection.

With liquid biopsy in the oncology field setting high expectations for the future of cancer care, tissue biopsies currently remain the gold standard for detecting and stratifying cancer 2. However, the accuracy of tissue biopsies is in some cases questionable. For instance, tissue biopsies can hardly capture the entire heterogeneity of a given tumour, thus offering only a “snapshot” analysis of a tumour fragment that might not contain the full spectrum of genetic alterations that belong to the entire tumour. Further, in most cases tissue biopsies are performed upon detection of a suspicious or well-established cancerous lesion with imaging techniques. This approach however, may overlook the presence of early cancer events that are below imaging detection limits. In contrast, liquid biopsies are non-invasive and can be taken multiple times over the course of a patient’s life. Even in patients with no evidence of disease, early primary tumours or occult metastatic lesions may contribute to the pool of CTCs and ctDNA and provide information about the genomic landscape of the tumour of origin.

While a large number of studies have been (and are) conducted on CTCs in the context of their underlying biology as well as their correlation with poor prognosis, most – if not all – ctDNA-based investigations have been in essence proof-of-concept reports. In this article, I will discuss some of the major advances in understanding the potential of CTCs and ctDNA contained within liquid biopsies, including their inherent limitations that will need to be addressed to implement the use of liquid biopsies in clinical practice.

Cancer is one of the leading global causes of death.

Liquid biopsies use blood and other bodily fluids to detect signs of tumours anywhere in the body.

Tissue biopsies are the gold standard in tumour detection but have their limitations.

CTCs and ctDNA have great potential, but their own limitations.


Liquid biopsy in oncology

Circulating tumour cells

Cancer cells that are released from the primary tumour site and enter the bloodstream are referred to as circulating tumour cells (CTCs). Whether the release of CTCs from a solid tumour is a stochastic process or determined by specific events occurring within the tumour tissues is currently unknown. Nevertheless, once entered in the bloodstream, CTCs strive for their survival, mostly because of the absence of adherence in circulation, strong shear forces and physical disruption due to their passage within small capillary beds 3. For these reasons, it is likely that CTCs undergo a strong selection process, with their half-life in circulation being estimated to be ranging from a few minutes to two hours, depending on their size and fitness for survival 4, 5. As a matter of fact, detection of CTC in patients occurring months or years after primary tumour resection indicates that tumour cells can re-circulate from secondary metastatic sites into the bloodstream 5, 6. For these reasons, CTCs can be considered to mirror the most current features of the primary tumour or the metastatic deposits they are derived from.

CTCs have been reported in cancers of the breast, colon, lung, prostate and pancreas, as well as in melanoma and glioblastoma multiforme, and their presence in the blood is widely associated with poor prognosis 4, 7–9. Currently, the only FDA-approved technology for CTCs enumeration is the CellSearch system 10. However, CellSearch is designed to identify exclusively those cancer cells expressing high levels of epithelial markers (ie EpCam and Cytokeratin), preventing the isolation of CTCs derived from non-epithelial tumours such as melanoma and glioblastoma multiforme, or CTCs with low EpCam and Cytokeratin expression. Alternative antigen-independent technologies have been developed for isolating CTCs from potentially all cancer types. For example, the Parsortix technology allows a size-based enrichment of live CTCs from unprocessed blood samples 11. Alternatively, the CTC-iChip allows a separation of nucleated cells from red blood cells on the basis of hydrodynamic cell sorting principles, and followed by inertial focusing of nucleated cells and deflection of white blood cells, ultimately allowing the isolation of unmanipulated CTCs in solution 12. More generally, a wide variety of CTC assays based upon either biological properties or physical parameters specific to cancer cells now enable enrichment of CTCs several logarithmic units over blood cells, from virtually all cancer types. Upon enrichment, CTCs can be enumerated, sequenced and used for ex vivo experiments.

To date, among the major achievements in CTC biology are the following. First, the presence of detectable CTCs in patients has been highlighted in several studies as a strong risk factor and associated with a poor prognosis, compared to cancer patients in whom CTCs are not detected, or where they are detected below a defined threshold 13–18. Second, the understanding that CTCs as present in the bloodstream of patients as single cells and as clusters of cells, with the latter being highly efficient precursors of metastasis 4. Third, molecular analysis of CTCs has been shown

CTCs are released from the primary tumour or secondary metastatic sites, and are living only a short time in the blood.

CTCs derive from a range of cancers, and can be identified by a range of technologies.

CTCs indicate tumour progression and metastasis, allow stratification of patients and can identify effective drug treatments.

Circulating tumor cells

Circulating tumor DNA

Key applications– CTC counts for good vs bad prognosis assessment– Ex vivo culture and testing of drug susceptibility– Molecular analysis for patient stratification– Understanding the biology of the metastatic process

Key applications– Quantification of minimal residual disease– Patient stratification– Companion diagnostic / treatment eligibility– Early cancer detection


instrumental to stratify chemosensitive versus chemorefractory patients before treatment 19. Fourth, when applying specific conditions, it has been possible to culture and expand CTCs from patients with various cancer type, and use them to test a variety of FDA-approved compounds to identify the best drug for each individual patient 20–22. Within the context of personalised medicine, the achievement of CTC cultures carries the outstanding potential to non-invasively monitor the changing patterns of drug susceptibility in individual patients, in real-time as their tumours acquire new mutations. More broadly, the increasing understanding of the features that characterise CTCs offers the promise to implement CTC testing in clinical practice.

Can we use circulating tumour cells for personalised treatments?

While the analysis of freshly isolated CTCs is clearly an opportunity to stratify patients before therapy decisions 19, the extremely low abundance of these cells in the peripheral blood of some patients remains a challenge in the context of personalised drug screenings. However, the possibility of expanding CTCs in culture or in xenograft mouse models has only very recently been achieved, carrying important implications for personalised medicine.

The first study reporting successful CTC culture was achieved with samples from breast cancer patients with brain metastasis 23. In this study, a fraction of CTCs was found to carry a specific protein signature (including the expression of HER2/EGFR/HPSE/Notch1 proteins) and to be particularly prone to form brain metastasis in animal models. These cells were cultured, and upon transplantation in mice, these CTC-derived cells displayed invasive properties and ability to re-generate brain and lung metastasis 23. However, the first example of CTC cultures with the aim of personalised drug treatment was provided in a separate study 20. There, CTC cultures were derived from six patients with hormone receptor-positive breast cancer, and firstly subjected to genome sequencing to assess a panel of cancer-associated mutational hotspots. Data analysis revealed pre-existing as well as acquired mutations in cancer-associated genes such as PIK3CA, ESR1 and FGFR2, among others. Drug sensitivity testing ex vivo and in xenografts of each CTC-derived cell line revealed patient-specific vulnerabilities as a proof-of-concept 20, highlighting the potential of CTC cultures and ex vivo drug screening to decide for the best possible treatment in a given patient. In another study, CTCs as well as tumour biopsies derived from prostate cancer patients were expanded as long-term organoid-like cultures 22. Seven newly generated organoid cell lines were shown to recapitulate the molecular diversity of prostate cancer subtypes 22. Other studies that followed could then show for the first time a successful CTC culture establishment from colorectal cancer 21 and lung cancer 24, paving the way to a detailed molecular and phenotypic analysis of CTCs in these diseases as well.

Altogether, several groups have now successfully established long-term CTC cultures from different cancer types. In the context of spersonalised medicine however, much work remains to be done. For instance, establishment of CTC-derived cell lines currently requires several months, and it is only possible from a restricted number of patients, usually those with the highest CTCs counts 20–22, 24. During this process, the corresponding patient in the clinic is likely to undergo additional treatment cycles, which are expected to re-shape the molecular portrait of his/her disease 25, 26. In this scenario, a drug screening on CTC-derived cells would not be up to date with the patient’s disease. For CTC cultures to become a strategy that enables real-time personalised medicine in the clinic, drug susceptibility testing needs to be achieved within just a few weeks,, if not just days, after blood draw. Thus, increasing the success rates of CTC culture assays along with the development of more rapid culture strategies is of paramount importance for achieving personalised treatment decisions from liquid biopsy, as well as to enable most patients with cancer to benefit from this approach.

Some patients have a low CTC count; but they can be expanded in culture.

Creating CTC cultures can yield significant results in determining the best course of patient treatment.

More rapid culture creation from CTCs will increase the efficacy of personalised drug screening.



Circulating tumour DNA (ctDNA)

Evolving molecular and cellular heterogeneity are hallmarks of cancer and pose a great challenge to tumour diagnostic and therapeutic decisions 27. Further, tumours adapt during therapy and develop resistance mechanisms that are responsible for treatment failure. As a consequence, tumour tissue biopsies taken once or twice during cancer onset and/or progression might only have a limited validity, and not be up-to-date with the latest acquired changes, especially those changes that occurred after the biopsy was taken. In contrast, the ability to interrogate the mutational profile of a tumour in a longitudinal fashion with minimally invasive sampling and along with therapy has the extraordinary potential to change how cancer patients are managed.

As a consequence to physiological cellular turnover, normal cells undergoing apoptosis and necrosis in various tissues are well known to release their content – including DNA – into the bloodstream. DNA in circulation is relatively stable, and when derived from normal cells it is referred to as circulating free DNA (cfDNA). Interestingly, cancer patients have much higher levels of cfDNA than healthy individuals 1. When tumours increase in volume, so does the cellular turnover and hence the number of apoptotic and necrotic cells within the tumour tissue itself, leading to the release of circulating tumour DNA (ctDNA) in the bloodstream, admixed with normal cfDNA. Most DNA fragments in circulation, including cfDNA and ctDNA, measure between 180 and 200 nucleotides in size, suggesting that apoptosis is likely to produce the majority of DNA fragments found in the bloodstream. Interestingly, shorter ctDNA fragments have been reported in at least some tumour types (eg hepatocellular carcinoma) as well as large cfDNA fragments of thousands of base pairs, which are probably the result of tissue necrosis 28.

Most studies focus on ctDNA that is released in the blood (plasma or serum) of cancer patients. Notably, the categories of body fluids that can be profiled have recently expanded well beyond blood and now include urine, cerebrospinal fluid, and saliva 29–32. For example, recent studies have shown that trans-renal DNA can be used to detect point mutations associated with drug resistance, and accurate molecular profiles of brain tumours can be successfully obtained from cerebrospinal fluid 29, 32. Additionally, the molecular landscape of head and neck cancers can be derived via ctDNA isolated from saliva 31. Generally, the biology of the tumour and its anatomical location dictates which fluid is most suited for liquid biopsies. For example, while ctDNA can be found in the blood of the majority of patients with metastatic disease, its amount in the blood of patients with brain tumours, such as gliomas and medulloblastomas, is often limited 33. In contrast, cerebrospinal fluid (which is secreted by the choroid plexus) can be successfully used to profile ctDNA in patients with tumour masses localised in the brain 29, 32.

Tumour-specific mutations in circulating DNA, highly diluted among normal cfDNA, were demonstrated several years ago using polymerase chain reaction (PCR)-based techniques 34, 35. In a similar fashion, the discovery of the high admixture of foetal-derived DNA in mother’s cfDNA opened up a new – and highly successful - avenue for prenatal genetic testing from peripheral blood 36. However, it is with the advent of the revolutionary next-generation sequencing (NGS) techniques that the field of ctDNA has observed a phenomenal expansion. As an example, while previous PCR-based sequencing technologies such as Sanger sequencing imposed several years of work, heroic efforts and very high costs to sequence one entire human genome 37, NGS allows the sequencing of one entire human genome in less than one day and at minimum costs (few hundreds US dollars) 38. Further, NGS allows the identification of cancer-derived ctDNA sequences that are greatly diluted among normal cfDNA in a patient 38. This technological breakthrough enables ctDNA detection in patients with virtually all cancer types, and it is likely to enable ctDNA interrogation in clinical practice.

Tissue biopsies can only take snapshots of constantly evolving tumours.

Mutating cells provide significant amounts of DNA fragments into the bloodstream.

ctDNA can be identified in the blood as well as other bodily fluids.

Next generation gene sequencing allows for quick and cheap detection of virtually all cancer ctDNA types.


Clinical applications of cell-free DNA

Detection of cancer by monitoring ctDNA is receiving outstanding attention not only in research labs but also in the clinical setting 39. Reliable detection and quantification of minimal residual disease (MRD) is currently employed in the management of patients with hematological malignancies but not in patients with solid tumours. Early detection of micrometastatic lesions that are below detection limit with current imaging procedures – such as CT or MRI scans – would largely increase the chances to prevent full-blown, incurable metastatic disease. Although the clinical relevance of ctDNA (as well as CTCs) for disease monitoring in metastatic patients is well established, the role of these biomarkers in early-stage patients remains to be clarified. MRD may be one of the most exciting key areas of application for liquid biopsies 40–42.

In patients with non-metastatic cancers, ctDNA-based liquid biopsies could be optimised to capture and monitor genomic markers of MRD following primary tumour resection, possibly preceding the development of clinical or radiologic recurrence.

Analogously, ctDNA analyses could be used to stratify patients who are at high risk for recurrence and spare low-risk patients from the toxicities of unnecessary systemic therapies. Along this line, recent studies have shown that the identification of tumour genomic alterations in the plasma of non-metastatic breast and colorectal cancer patients anticipates the diagnosis of clinical metastatic relapse 43–45.

With the liquid biopsy field advancing at the speed of light, the first two companion diagnostic tests for the determination of EGFR mutations in ctDNA have been approved by the regulatory agencies in Europe and in the USA. These tests can now be used to guide anti-EGFR treatment in EGFR-mutated non-small-cell lung cancer patients using blood when access to tissue is impaired. While these examples demonstrate the clinical applicability of ctDNA, additional interventional studies are required to demonstrate its clinical utility, ie, the capacity to determine whether to adopt or to reject a certain therapeutic action.

Ultimately, the holy grail of liquid biopsies is to be able to detect cancer early enough (even before the patient experiences any cancer-related symptoms) so that the disease can be eradicated and the patient cured. To this end, ctDNA screening in healthy individuals could be used to identify cancer-related mutations arising over the course of a person’s life. While several companies have already started to embark in such projects, the feasibility of this approach remains to be assessed using very large patient cohorts and assays that are able to overcome sensitivity and specificity issues, such as the distinction between benign and malignant tumours as well as possible over-interpretation of false-positive results.

One of the most exciting uses of liquid biopsies will be in early cancer detection.

This could also be the case for non-metastatic cancers.

Stratification could also spare low risk patients from toxic therapies.

Regulatory agencies have approved the use of liquid biopsies in companion diagnostic tests.

ctDNA screening in healthy individuals could reveal cancer-related mutations; although it is not certain how results will be interpreted in large cohorts.



Not as easy as it seems: challenges associated with liquid biopsies

While the field of liquid biopsy has expanded exponentially in the past few years, setting the stage for very high expectations in the near future, results must be interpreted with caution.

Concerning CTCs, their use in clinical practice might be limited by the high costs that accompany CTC-enrichment technologies, and the fact that only a restricted number of patients –usually those with most aggressive cancers – have a high-enough CTC concentration that allows their detection in 1–2 tubes of blood. Further, while extraordinarily promising, CTC expansion ex vivo or in xenograft models for personalised testing of drug susceptibility might introduce a selection step that reduces the inherent heterogeneity of the initial CTC population, and select for clones with proliferative advantage in the experimental setting. Last but not least, it is currently not possible to achieve CTC expansion and drug testing within a timeframe that would benefit patients, hence more work needs to be done to optimise each step of the expansion protocol and to realise a CTC expansion and drug testing pipeline that is fully translatable to the clinic.

Concerning ctDNA, the greatest challenge is not only the identification of very low amounts of ctDNA in blood samples with variable amounts of background cfDNA. Researchers must also choose the right panel of cancer-specific alterations to look for, versus the choice of interrogating the whole genome, for which the price to pay may be a reduced sensitivity of the assay (ie reduced likelihood to identify ctDNA when highly diluted, versus a higher likelihood to do so with a targeted gene panel approach). Besides sensitivity, the specificity of the results also poses some additional challenges when thinking about application of ctDNA sequencing in the clinic. Cancer-associated mutations occur with increasing age even in individuals who never developed cancer during their lifetime. For example, clonal hematopoiesis with somatic mutations was observed in 10% of persons older than 65 years of age and was a strong risk factor for subsequent hematologic cancer. However, the absolute risk of conversion from clonal hematopoiesis to hematologic cancer was modest (1% per year; 46). Thus, the detection of ctDNA in a patient might occasionally induce substantial anxiety and extensive diagnostic procedures in healthy individuals. Large studies with sufficiently powered cohorts of patients will be needed to address these potential concerns.

CTC processing is high in cost, reduces cell heterogeneity, and is slow.

ctDNA comes in low amounts and cancer specific mutations have to be identified; there is a danger of misdiagnosis on low conversion rates.


Summary and concluding remarks

While the field of liquid biopsy in oncology still presents with some open questions to be addressed, the potential of CTC and ctDNA analysis for the care of patients with cancer is extraordinary. Within the next 5–10 years, we could witness the implementation of liquid biopsy in the clinical setting, using noninvasive blood sampling rather than (or additionally to) tissues as a primary source of information for optimising personalised medicine, disease monitoring, as well as early cancer detection. This scenario would change the current way oncology is practiced, and possibly lead to a better outcome for cancer patients.



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AuthorNicola Aceto is a Swiss National Science Foundation Professor of Oncology and Group Leader of the Cancer Metastasis laboratory at the University of Basel, Switzerland. Previously, he trained at Harvard Medical School and Massachusetts General Hospital in Boston, at the Broad Institute of MIT and Harvard in Cambridge, and at the Friedrich Miescher Institute in Basel. He has authored several high-impact publications in leading journals in cancer field and he is an inventor on 4 patents related to the diagnosis and treatment of cancer. Prof. Aceto is the recipient of several prestigious awards, including an honorable mention within the Wachtel Cancer Research Award from the American Association for the Advancement of Science, an abstract award from Harvard Medical School, and an ERC starting grant from the European Union. He also serves as scientific advisor for several pharmaceutical companies operating in the oncology field, and he has been an invited speaker in a number of congresses and organisations, including the University of California Berkeley, Google[x] Life Sciences, the Novartis Institute for Biomedical Research, and Cancer Research UK.


Liquid biopsy – a new blood test for cancer challenges the insurance industryGiselle Abangma, Christoph Nabholz, Florian Rechfeld, John Schoonbee

Liquid biopsy is a new blood test used that could help detect and treat cancer. This new molecular technology has been developed to capture and analyse genetic material that tumour cells release into the blood with potentially high specificity and sensitivity. It is easy to obtain a blood sample, which makes this concept promising as a less invasive complement to traditional tissue biopsy techniques. It has the potential to transform clinical practice by providing an effective personalised medicine platform.

Ultimately liquid biopsies could bring substantial benefits to cancer patients and improve survival outcomes. However, they also create new risks and exposures for life and health insurers, particularly for critical illness (CI) and cancer products. Similar to other new screening tools introduced into clinical practice, liquid biopsy has the potential to increase cancer incidence rates, and affect the number of CI or standalone cancer product claims. This risk is especially pronounced where long-term guarantees are in place.

This article discusses the current status and clinical applications of liquid biopsy, and the potential implications and considerations for insurers. What are the potential impacts on CI business? How can the industry manage these new risk exposures in order to ensure we continue to provide sustainable products for those who need them the most?

Providing financial cover for cancer therapy

Critical illness (CI) insurance is a living benefits product that provides indemnity cover for major medical diagnoses, events or diseases including cancer. Where possible, each disease is specifically defined according to current medical criteria. However, as medical technology advances, these definitions can become outdated, particularly with contracts that remain in force for decades. This is especially evident with cancer and the rapid evolution of new techniques such as liquid biopsy.

Evolving CI cancer definitions

CI cancer definitions have not changed much in recent decades. For solid tumours, histopathological proof of invasion is still the mainstay definition in most markets. Certain exclusions have been added where increased early detection led to unexpected claims payments for less serious, usually early stage cancers.

Examples of these are early thyroid and prostate cancer exclusions now seen in many markets. Although traditional tissue biopsy is still the standard for confirming a cancer diagnosis clinically, it has some challenges that a liquid biopsy could potentially overcome.

Liquid biopsy is a new blood test that could help detect and treat cancer.

Treatment and survival outcomes of liquid biopsies will require insurers to review portfolios.

Should liquid biopsies be widely used, the implications could be significant.

Liquid biopsies may change the speed and methodology with which we identify cancer.

Insurers currently require traditional biopsy to define cancer and write exclusions for less serious cancer.


Liquid biopsy – a new blood test for cancer challenges the insurance industry

Liquid biopsy – a new minimally-invasive genome based test enters clinical practice

Liquid biopsy is a minimally invasive technique that can identify molecular biomarkers in blood and other body fluids. Mainly used for cancer, liquid biopsies allow for detection and analysis of circulating tumour material (cells or DNA) shed into the blood from the primary tumour and from metastatic sites. A liquid biopsy is able to assess circulating tumour DNA (ctDNA), tumour cell contents such as exosomes and actual circulating tumour cells (CTCs). While liquid biopsy may add complementary information to the characterisation of cancer, tissue biopsy will remain the standard for cancer diagnosis for the foreseeable future.

Figure 1: Tumor releases a multitude of biomarkers into blood

Current and potential use of liquid biopsy in clinical practice

The global market for liquid biopsy was valued at USD 18 million in 2015 and is estimated to grow to almost USD 6 billion by 2030 (GVR Global Indistry Report 2030). The field is considerably influenced by the developments in new sequencing technology and it is expected that upon successful completion, commercialisation of these tests will significantly boost the liquid biopsy market[2].

While not labelled as a liquid biopsy, in August 2014 the U.S. Food and Drug Administration FDA had already given green light to Cologuard, a non-invasive screening test for colorectal cancer. The test looks for both abnormal DNA and haemoglobin in the stool associated with early colorectal cancer or precancerous lesions most likely to develop into cancer. The test is recommended for use every three years for non-symptomatic, average-risk adults 50 years or older. Patients with positive test results are advised to undergo a diagnostic colonoscopy. At an average price of USD 600 compared to the simpler faecal occult blood test (FOBT) costing around USD 4 per test it is a less preferred option.

On 1 June, 2016, the FDA approved the first purely blood-based liquid biopsy test, a companion diagnostic test that can detect EGFR gene mutations in the blood of non-small cell lung cancer (NSCLC) patients to determine which patients are eligible for EGFR-targeted therapy with erlotinib (Tarceva)[1].

Other liquid biopsy applications undergoing clinical trials include those that can monitor treatment response and development of resistance, disease prognosis, identify genetic markers for targeted therapy, and detect disease recurrence. These blood tests may also hold the potential for early detection of cancer in asymptomatic individuals. Clinical trials are ongoing and far more research is needed to establish the value of such a screening test and obtain FDA approval.

Liquid biopsy will for the foreseeable future be regarded as complementary to standard biopsy by insurers.

2

3

1

Tumor releases a multitude of biomarkers into blood

Tumor biomarkers in blood1. Cell-free DNA (cfDNA)2. Circulating tumor cells (CTCs)3. Exosomes and micro vesicles

CTC

DNA

Primarytumor Blood vessel

Liquid biopsy is likely to be a large market.

The FDA has already approved a form of liquid biopsy screening …

… as well as a biopsy based on blood …

… with other clinical trials ongoing.


While clinical trials are ongoing, liquid biopsy is becoming increasingly important for improving cancer therapy and could eventually become an alternative or adjunct for histological cancer diagnosis and staging. The potential application of liquid biopsy is to enhance treatment monitoring, disease screening and applicability of targeted therapy.

Monitoring Screening Treatment

Treatment response Early detection Genomic profiling

Drug resistance Secondary cancer Prognosis

Disease recurrence Diagnosis Minimal residual disease

Table 1: Potential applications of liquid biopsyLiquid biopsies have a role to play in monitoring treatment response, drug resistance and disease recurrence. Similarly it may be used for cancer screening and support diagnosis. Finally it helps to genetically profile the cancer in order to better target therapy and assess disease severity and prognosis.

Despite the potential of liquid biopsy to provide predictive and prognostic information, it is not yet established as a cancer screening tool and cannot currently be used for cancer diagnosis. Clinical validity and utility of this test need further evaluation.

While for the foreseeable future tissue biopsy will remain the standard for diagnosing cancer, liquid biopsy may be a good alternative where: ̤ Not enough tumour tissue is available ̤ The tumour is difficult to reach ̤ There is a need for regular monitoring to guide the patient treatment approach

What does this mean for the insurance industry?

The use of liquid biopsy in routine clinical practice is still in its infancy. However, it has the potential to change the way cancer is diagnosed and treated in the future. This can impact the industry in a number of ways.

1. Cancer incidenceChanges in cancer screening and diagnosis may lead to an increase in CI cancer claims, similar to what occurred with other new screening and diagnostic tools such as PSA testing for prostate cancer. The magnitude of this may be substantial. We see two escalating scenarios:

1. Screening: Liquid biopsy holds the potential to be a diagnostic cancer screening tool which is why we need to monitor it closely. A positive test result may allow for earlier diagnosis and better disease management. However, screening also enhances the risk of over-diagnosis – identifying a “disease” that would never have caused symptoms or premature death. Such over-diagnosed cancers will lead to unnecessary medical intervention and psychological distress, as observed with PSA testing for prostate cancer and recently with ultrasound screening for thyroid.

2. Evolving diagnostic criteria: Liquid biopsies could become accepted as a de facto cancer diagnostic tool for certain cancers. This could lead to many contentious claims and could have a negative impact on the industry. The insurance industry’s cancer diagnosis definitions need to be reviewed so that they are in line with changes in clinical practice. This will certainly help with new business, but does leave a large in-force book with significant risk.

Despite predictive and prognosis potential, liquid biopsies cannot yet be used in clinical diagnosis.

Liquid biopsies will improve diagnostics …

… but may lead to an increase in contentious claims and over diagnosis.



A recent example for increased over-diagnosis rates is thyroid cancer in South Korea. Since the early 2000s, South Korea experienced a rapid increase in thyroid cancer incidence, especially in women. It is believed this increase is due to the wide utilisation of ultrasound-based screening. Furthermore, despite this dramatic increase, mortality from thyroid cancer has remained stable for several decades[3] – a combination that is characteristic for over-diagnosis.

Figure 2: Korea thyroid cancer incidence trendsThe age-standardised rate (ASR) was calculated based on Korea’s mid-year population of 2000. During the same period the observed age standardised mortality stayed flat.Source: Annual report of cancer statistics in Korea in 2013.

2. Impact on critical illness cancer definitionsCancer definitions vary by market. Some have market-standardised cancer definitions that must be adopted by all insurers, while others allow companies to define their own. Definitions provided by industry organisations will require more time to get industry consent.

Although most markets explicitly require histopathological proof, explicit liquid biopsy exclusions could create an additional safety net. Definitions that only require cytology or ICD codes would be less likely to protect against a diagnostic liquid biopsy wave. How our current histological proof based cancer definitions will stand up to the challenge of a positive liquid biopsy remains to be seen.

To create a truly forward looking cancer definition that explicitly includes liquid biopsy diagnosis is currently not feasible, as the clinical evidence needed to exclude over-diagnosis is missing.

0

20

40

60

80

100

120

140 Age-standardized thyroid cancer incidence

MaleFemale

201320122011201020092008200720062005200420032002200120001999

Liquid biopsy may challenge traditional cancer definitions within insurance but not at the present point.


Box 1: Model critical illness definitionThe current approach of the cancer definitions proposed by the ABI aims at distinguishing invasive from benign cancer. The definitions are regularly reviewed and are up for discussion in 2017 at which point liquid biopsy test should be addressed.

Source: Association of British Insurers (ABI) Statement of Best Practice for Critical Illness Cover – April 2014.

3. Impact on pricing and long-term guaranteesSince pricing assumptions are usually based on historical experience, advances in diagnostic techniques and their potential impact on incidence are not accounted for during pricing. For CI and cancer products to remain sustainable, the industry needs to take measures to protect its new business, but also mitigate risks for the in-force books. Tightening definitions to exclude liquid biopsy and/or reducing the duration of long-term CI guarantees are important measures to consider. These measures will allow for flexible adoption of cancer definitions according to changing clinical cancer diagnostic protocols.

Any increase in cancer diagnostics will upset insurance pricing models and will require proactive policy management.

CI cancer definition – excluding less advanced cases

Any malignant tumour positively diagnosed with histological confirmation and characterised by the uncontrolled growth of malignant cells and invasion of tissue.

The term malignant tumour includes leukaemia, sarcoma and lymphoma except cutaneous lymphoma (lymphoma confined to the skin).

For the above definition, the following are not covered:

All cancers which are histologically classified as any of the following: ̤ pre-malignant ̤ non-invasive ̤ cancer in situ ̤ having borderline malignancy or ̤ having low malignant potential

All tumours of the prostate unless histologically classified as having a Gleason score of 7 or above or having progressed to at least TNM classification T2bN0M0.

Chronic lymphocytic leukaemia unless histologically classified as having progressed to at least Binet Stage A.

Any skin cancer (including cutaneous lymphoma) other than malignant melanoma that has been histologically classified as having caused invasion beyond the epidermis (outer layer of skin).



4. Product designThe introduction of liquid biopsy in routine clinical practice could change how cancer is diagnosed and staged which could potentially alter the current TNM staging system1. This might have implications for severity based cancer products where a cancer staging could one day be based not on histology but rather on defined genetic alterations. Creating products that use some other severity criteria might circumvent this problem.

Using liquid biopsy for targeted therapy and monitoring of treatment response will likely increase survival rates and hence the number of cancer survivors still at risk for relapse. Products that allow for recurrence should regularly review their assumptions as relapse rates may fluctuate.

5. Anti-selection riskThe increasing access to liquid biopsy tests increases anti-selection due to potential asymmetry of information at the underwriting stage. A negative liquid biopsy test result could deter or delay the purchase of insurance since a negative test result may indicate a lower risk, meaning only those with higher risk of developing cancer buy cancer cover. The rapidly falling cost of DNA sequencing further exacerbates the risk of anti-selection as liquid biopsy tests become affordable to a large consumer base[4].

Conclusion and outlook

For the foreseeable future, histopathology will remain the standard for cancer diagnosis and staging. Liquid biopsy needs to be clinically validated and proven to be cost-effective before it can be used in population screening and possibly diagnosis. As it stands, liquid biopsy tests should not be accepted as evidence of a valid CI claim.

However, it is important to consider and adapt now to this future possibility when designing products, pricing and definitions. Insurers need new definitions that are able to withstand changes and advances in diagnostic techniques and if this is not possible, they should reduce long-term guarantees.

With all the changes happening in diagnostics, the industry should keep in mind the purpose of the critical illness product – what it is intended to cover and how it is priced. We must ensure we pay fair and reasonable claims, and protect against inappropriate claims that might render the product unsustainable and unavailable to those who need it the most.

To keep abreast of the latest developments in cancer diagnostics, Swiss Re is engaging with leading experts in liquid biopsy and other novel cancer diagnostics. The 2016 Expert Forum on Cancer Diagnostics gathered 16 global experts from a variety of fields. See reference [5] below for more information.

We will continue to closely monitor this topic as we do with others that have the potential to change the life and heath landscape. Stay tuned.

1 The TNM system is the most widely used cancer staging system. It describes the amount and spread of cancer in the body, using TNM. T describes the size of the tumour and any spread of cancer into nearby tissue; N describes spread of cancer to nearby lymph nodes; and M describes metastasis (spread of cancer to other parts of the body).

Product design will also have to be reviewed to capture survival rates and staging criteria.

Information asymmetries from liquid biopsies could skew CI purchasing intentions.

Ultimately liquid biopsies should not qualify for a valid CI claim and will not do so for the foreseeable future.

However, liquid biopsies could change the business environment in other ways, and insurers must be ready for change.


References1. FDA approves first blood test to detect gene mutation associated with non-small cell

lung cancer http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm504488.htm

2. Global liquid biopsy market size and forecast http://www.grandviewresearch.com/industry-analysis/liquid-biopsy-market

3. Association between screening and the thyroid cancer “epidemic” in South Korea: evidence from a nationwide study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5130923/

4. Seeing the future? How genetic testing will impact life insurance http://media.cgd.swissre.com/documents/Genetics_Seeing _the_future.pdf

5. Expert Forum on Cancer Diagnostics – Swiss Re conference report http://media.cgd.swissre.com/documents/Conference_report_Expert_Forum_on_Cancer_Diagnostics.pdf

AuthorsGiselle Abangma is a Health Research Analyst in the Swiss Re Life & Health R&D department. She has worked on a variety of disease areas including cancer, diabetes and cardiovascular disease. Prior to joining Swiss Re, she worked as a Health Economist at the University of Oxford’s Health Economics Research Centre (HERC) and as an Analytical Chemist with GlaxoSmithKline plc. Giselle has a first class bachelor’s degree in Pharmaceutical Sciences and completed an MSc in Health Economics from the University of York and another in Health Promotion and Public Health from Brunel University.

Dr Christoph Nabholz is Head of R&D Life & Health in Swiss Re Group Underwriting. His team provides innovative and market-leading population trend research addressing the impact of technology, medical advances and human behaviour on health and mortality. Before joining the L&H R&D team he headed Business Development at the Swiss Re Think Tank, Centre for Global Dialogue. He entered Swiss Re in 2002 in Global Life & Health Underwriting where he served as Swiss Re’s Global Genetics Consultant. Prior to joining Swiss Re, he was a postdoctoral fellow in genomics and functional genetics at Harvard University and has a PhD in molecular genetics from the University of Fribourg, Switzerland.

Dr Florian Rechfeld is a Senior Research Analyst L&H in the Swiss Re Life & Health R&D department. His research interests span many areas including advances in human genome sequencing and genetic testing and the future impact of personalised medicine on healthcare. Prior to joining Swiss Re, he was a postdoctoral fellow at the Institute of Infectious Diseases and Oncology at the University Children’s Hospital in Zurich. He also received a PhD from the Institute of Medical Biochemistry at the Innsbruck Medical University in Austria.

Dr John Schoonbee joind Swiss Re in 2011 and is the Global Chief Medical Officer. He and his team are involved in many aspects of life insurance, including product development, risk and claims assessment, as well as helping with pricing some of the more complex medical life and health products. John graduated from the University of Cape Town in 1995, and performed his internship at Groote Schuur Hospital. After some years in private medical practice he joined the corporate world, which included working at a company that specialised in corporate sick leave management. While running his own sick leave and disability consulting company he joined RGA in South Africa and became Chief Medical Officer and Head of Research.

We would like to thank Urs Widmer, Swiss Re, for his valuable contribution.


CRISPR – Hacking the biological hard driveThomas Wildhaber, Séverine Rion Logean, Christoph Nabholz

In 2012, researchers identified a new markers-free gene editing mechanism. This exciting new technology, CRISPR, has revolutionised the industry and academic research. CRISPR allows for a highly efficient and precise gene editing process. In humans, the technology is already being used successfully to manipulate immune cells, reprogramming them to recognise cancer cells. Several such cell therapy approaches are either being planned or currently tested in US clinical trials.

Furthermore, CRISPR technology could be used to cure genetic diseases at an embryonic stage. Recent published research in China has demonstrated successful use of CRISPR gene editing on human embryonic stem cells. The treatment of embryonic stem cells raises significant legal and ethical questions; a number of countries prevent such procedures by law.

Although the success rate of the technology is very high, we have yet to establish a completely failure-free procedure. However, gene editing will surely have a significant impact on future human disease treatment strategies.

Introduction

The rapid identification of genes associated with human disease has revolutionised the field of medical genetics. Understanding the underlying genetic and molecular mechanisms has allowed for the development of new personalised therapeutic strategies. The completion of the Human Genome Sequencing project in 2003, followed by new powerful genome analysis tools coming to market, has allowed researchers to map out most disease associated genes. This has resulted in a deeper understanding of the molecular mechanisms of disease development. While this has been a revolution in itself, a new technology has come to market that allows us to go beyond understanding the genetic basis of disease and actively take corrective action in the genome. In theory, any malfunctioning gene can be replaced by a healthy copy. This exciting new technology is known as CRISPR and is based on bacterial enzymes, which are able to precisely target and edit any position on a genome. This opens a new world of almost infinite possibilities; but one which also carries significant risk and ethical concerns.

The history of genome editing

The ultimate goal of curing of genetic diseases is to exchange faulty genes with healthy ones. The first clinical use of gene therapy was in 1990, when a patient was successfully treated for a severe immune disease with genetically modified immune cells1. Motivated by this exciting early achievement, researchers started to use viruses as vectors for carrying healthy gene copies and integrating them into the genome. Unfortunately, the virus approach failed due to the lack of control of the virus integration into the genome. One patient started suffering a massive immune response caused by the deployed virus, resulting in death only four days after treatment. This fatal trial was a major setback for gene therapy. Moreover, the viruses used to integrate the healthy genes into the genome were found to integrate into multiple genome sites, which subsequently caused cancer2. To overcome this unspecific genome integration, researchers started to develop enzymes, which could precisely recognise DNA targets. These enzymes were found to introduce a break into the DNA, which would activate the cell-inherent DNA repair mechanism. The DNA repair machinery makes use of a DNA template, which is flanked by DNA sequences precisely matching the border of the break. Providing the DNA repair machinery with an artificially designed DNA template flanked by the target DNA site allowed the integration of new genes at the precise gene loci. Although these enzymes offered the potential of targeting any programmed DNA sequence, the design effort was enormous, given the need to design a new enzyme for each target. This design burden was significantly lowered with the discovery of the CRISPR system in 20123.

CRISPR technologies offer the potential to replace malfunctioning genes with a healthy copy.

The use of viral vectors for gene editing proved too risky; and dedicated DNA loci specific enzymes too expensive.



How does CRISPR work?

In contrast to enzymes that recognise the DNA target by themselves, the CRISPR system makes use of a target specific RNA that guides the CRISPR enzyme to the DNA site of interest. Therefore, only the guiding RNA, which is complementary to the DNA target, needs to be designed and manufactured in the lab. The procedure of gene editing remains the same. The CRISPR enzyme introduces a break in the target DNA, the cell-inherent DNA repair mechanism is activated, and an artificially designed DNA template is presented and inserted. The CRISPR system was initially limited to certain DNA sequences, but with the discovery of further CRISPR enzymes and increasing design knowledge, CRISPR now offers a very precise, flexible and efficient tool for genome editing. Although not discussed here, the CRISPR system can also be used to alter gene expression by manipulating the epigenetic layer of the gene target without changing the DNA sequence3.

Genomic DNA

Cas9

Guide RNA

Human cells

Zebra�sh

Bacterial cells

Donor DNA

Matching genomic sequence

Targeted genome editing

Repair

PAMsequence

Figure: CRISPR – Hacking the biological hard driveSource: Emmanuelle Charpentier, Jennifer A. Dounda, Nature, 2013Reprinted by permission from Macmillan Publishers Ltd: Nature, CRISPR – Hacking the biological hard drive, 2013

Common DNA cutting enzymes do two jobs: They first recognize and second cut the DNA. This kind of enzymes were the first used in targeted gene manipulation. However, this means that for every DNA target scientists needed to design a new enzyme, a highly time consuming undertaking. The challenge: enzymes will not cut always at the correct position. CRISPR recognizes the target DNA supported by a helper, the guide RNA. This guide RNA directs the CRISPR to the target, where CRISPR can cut the DNA at a predefined position. The DNA repair mechanism takes care of the damage and incorporates a present so called donor DNA. This donor DNA is the correct DNA to replace a mutated gene in order to extinguish a genetic disease (Picture D) 1. The following are challenges to be solved with regard to the application of CRISPR in human gene therapy: a) sporadic incorporation of DNA at the wrong position (off target problem) b) sporadic lack of incorporation of donor DNA, leading to mutation by deletion 1,4, c) timing; when on a time axis CRISPR is doing the job. This leads to the phenomenon of mosaic organism, where not all cells of an organism get targeted DNA replaced5.

CRISPR allows a precise, flexible and efficient target for gene editing.


Despite this enormous progress, there are still many challenges ahead, before a safe gene therapy approach can be brought to market. One issue is the efficiency of CRISPR genome integration. Once injected into a mouse zygote cell, the CRISPR system cannot be guaranteed to integrate into the target DNA template. This leads to the phenomenon of an adult mosaic mouse, where some cells carry the insertion and others do not. This can be solved by further inbreeding of the mouse, to the stage where all cells carry the same genome6. Furthermore, CRISPR mediated genome manipulation appears to also integrate off-target DNA and introduces an unexpected high number of single-nucleotide variants (SNVs). It was concluded that the current in silico modelling of the RNA design is not failure free and must be improved. Although the SNVs appeared mainly in non-coding regions, it was noted that this might cause future problems, due to non-coding regions being involved in the regulation of gene expression7.

The role of CRISPR in research and development

The advent of the CRISPR system has revolutionised academic and pharma-industry research and development. It is now possible to generate in one single step a mouse based disease model within three weeks. This compares to around one year using the classic transformation and breeding approach. Animal and human cells have been successfully modified using CRISPR. Hence, scientists can quickly create disease-based genetically modified organisms and test their scientific hypothesis in an in vivo model6.

CRISPR can also be used as a potential gene therapeutic, as demonstrated by its ability to partially remove the viral DNA from the genome of hepatitis B infected hepatocyte cells3. A similar approach was successfully tested for the treatment of HIV by the CRISPR initiated deletion of the CCR5 T-cell co-receptor, which is necessary for the HIV virus to evade the T-cell. Successfully treated T-cells demonstrated in vitro resistance to HIV-1 infection8.

Another exiting approach is to reengineer T-cells to target cancerous tissue. Some tumours escape T-cell-initiated programmed cell death by presenting the PD-1 ligand to the PD-1 receptor, which is present on the T-cell. In this immunotherapy approach, the CRISPR system is used to mediate PD-1 disruption in T-cells, which provides the T-cell with the ability to induce cancer cell death7.

CRISPR gene editing is not perfect; insufficient integration efficiency and development of off target single-nucleotide variants, amongst other difficulties, need to be solved before it can be used safely.

CRISPR can significantly increase speed of genetic research.

CRISPR can be used as a gene therapeutic …

… as a means of reengineering T-cells …



Finally, stem cell therapy is another promising technology in combatting genetic disease. Stem cells derived from embryos are pluripotent, meaning they have the ability to develop into any other cell type. Despite their development potential, there are ethical concerns about using embryonic stem cells. Therefore, current research is focused on reprogramming adult stem cells, which can be derived from skin or blood cells. These can be reprogrammed to make them potent stem cells (inducted pluripotent stem cells, iPSC) and put back into the patient9. Stem cells are currently being investigated for their ability to grow and replace damaged or diseased tissue (regenerative therapeutics). Hematopoietic stem cells are the most widely used stem cells and are deployed to treat blood diseases. In an in vitro experiment, it was demonstrated that reengineered blood stem cells of a cystic fibrosis patient became functional again10. A similar approach was applied to muscular dystrophy research, where the CRISPR mediated correction led to normal expression of functional dystrophin11.

Despite progress made in CRISPR mediated gene manipulation, there are still outstanding challenges, such as off-target avoidance, understanding the long term toxicity of CRISPR, the prevention of mosaicism, the integration of DNA after the one cell stage and the insertions of SNVs. Furthermore, researchers need to investigate the influence of chromatin confirmation on the CRISPR mediated insertion and on the later expression level of the new gene5,12.

A growing industry

A number of research companies have been established in recent months specialising in CRISPR technology. They break down into two types: those doing basic research to provide knowledge and tools (including Caribou Biosciences, Synthego, eGenesis); or those researching human genetic diseases (such as Poseida Therapeutics, Agenovir, CRISPR Therapeutics).

Synthego is undertaking basic research with the goal of providing a cheap and an effective CRISPR gene editing kit; whereas eGenesis wants to enable the transplantation of pig organs into humans. Agenovir is doing research into viral DNA removal against cancer and wart cells. CRISPR Therapeutics is addressing monogenetic diseases such as cystic fibrosis or beta thalassemia. Start-ups frequently collaborate with major pharma companies, who make use of their experience in developing therapies, such as CRISPR Therapeutics’ joint venture with Vertex Pharmaceuticals targeting cystic fibrosis13.

Gene drive

Gene drive is another example of the use of the CRISPR system. Gene drive works as follows: A gene of choice is inserted together with the encoded CRISPR system into the genome of a target species. If the homozygote carrier (one allele of this cassette in each of two chromosomes) for this new gene mates with a wild type carrier, the heterozygote will, through the CRISPR system, insert itself into the second allele, and so on. With gene drive, a desired gene can be spread extremely efficiently over a population, especially when the desired organism has a high reproduction rate, such as flies or mosquitos. Applications for these techniques include preventing the spread of insects that carry pathogens, controlling invasive species or eliminating herbicide or pesticide resistance14.

Oxitec, for example, has created gene drive mosquitos (for Aedes aegypti a malaria carrier) that result in an increase of dead offspring. The genetically manipulated mosquitos were successfully tested on Cayman Island, where the population was reduced by 80% within 11 weeks15. Additional field experiments are planned in Florida, where the FDA already approved the test16. Furthermore, New Zealand and Australia are considering the use of gene drive technics to eradicate invasive species from their countries17.

… and in the use of stem cells as a means of combatting genetic disease.

Nonetheless,there are challenges to CRISPR that need to be resolved.

A number of research companies are using CRISPR …

… across a range of activities.

Gene drive uses CRISPR technology that can target species with high reproductive rates such as mosquitos …

… with trials against malarial mosquitoes taking place in a number of countries.


Clinical progress

Gene therapy approaches for human genetic diseases are of particular interest. Gene therapy can be either undertaken directly within the organism (in vivo) or ex vivo in genetically reprogramed cells taken from the organism and transplanted back. This approach has the potential of treating human genetic diseases, viral diseases and cancer18. In 2016 a Chinese research team tested for the first time the CRISPR system in a human clinical trial. They collected T-cells from a patient, who suffered from lung cancer, and genetically modified the T-cells so that they would recognise the lung cancer cells. Once injected back into the patient, the hope is that the modified T-cells will start attacking target lung cancer cells. First results are expected to be presented within a year19. The results of this new immunotherapy approach are widely awaited by oncologists, and similar trials are under FDA review. The plan is to edit the T-cell receptor in such a way that the immune cell is able to detect the cancerous tissue and induce programmed cell death20.

In another study, researchers were able to cure sickle cell disease in vitro21. In the next phase of research, the FDA is reviewing the clinical trial, in which corrected stem cells are transplanted back into the blood system of patients22.

Regulatory action

The UNESCO panel on gene editing recommended that any editing of the human genome should be avoided to protect against the manipulation of inheritance of future traits. This has been commonly accepted across the word23. On the topic of embryonic stem cell research, the world is less united. In Europe there are countries which allow research on embryonic stem cells under certain conditions, such as Sweden, Spain, Finland, Belgium, Greece, Britain, Denmark, the Netherlands and Switzerland. However, in other states, such as Germany, Australia, Ireland, Italy and Portugal, it remains illegal. A similar picture can be seen at state level laws within the United States. Asia on the other hand is relatively liberal, particularly China, where research and therapeutic cloning of embryonic stem cells are allowed. The use of patient-owned stem cells for cell therapy is separately regulated by the corresponding authority in each country24.

Ethical debate

Gene manipulation raises ethical concerns. The use of patient-owned cells for cell therapy approaches is less controversial, as the individuals can give consent to manipulation and reinjection of their own cells. The genetic manipulation of embryonic stem cells is, however, extensively debated. The main question raised is what point marks the beginning of life. In China, for example, it is believed that human life starts at birth. In other countries embryonic stem cells can be used for research purposes only. No further development is permitted23.

The manipulation of the germline genome, which leads to gene manipulated progenies, such as in the gene drive approach used in animals, is a fundamentally different ethical question. The release of genetically manipulated organisms might lead to irrevocable changes of ecosystems, even to the eradication of the target organism. Are we allowed to eliminate an organism from the surface of the planet? Or do we simply accept 500 000 people dying every year due to malaria? To what extent are we obliged to save human life?23

Although many diseases could be eradicated by allowing preimplantation diagnostics, similar questions could be asked regarding manipulation of the human germline. If we are able to eliminate most monogenetic diseases via simply exchanging the “wrong” gene with the “correct” one, why should we not do it in order to banish diseases like cystic fibrosis or Huntington’s disease? However, genetic manipulation could also be used to change other areas of our gene, coding for eye colour or body stature. Where would we draw the limits and who would control the gene technology? It is beholden on society to consider the striking ethical issues CRISPR technology raises and how we manage them25.

With a number of ongoing human trials, China is positioning itself as a leader in CRISPR technology.

There is variation across the world in how embryonic stem cells are regulated …

... although individual consent to use of their own cells is not disputed.

Significant ethical issues exist around gene drive techniques ...

… as well as to the degree to which CRISPR should be used for non-medical use.



Impact to the insurance industry

There are real commercial and risk implications of CRISPR technology on the insurance industry.

BiohackingCRISPR technology, being both cheap and available, can be used for good; could be used inappropriately; or could be misused to cause severe environmental damage. Biohackers could allow an uncontrolled release of gene-manipulated organisms into the environment. This may lead to suppliers of CRISPR technologies facing third party liabilities. Moreover, environmental losses as a result of genetic manipulation could themselves prompt claims over a range of lines.26 Finally, biohacking could potentially play a role in bioterrorism, with new gene drive organisms leading to the destruction of the targeted environment.27

Pharmaceutical industryThe application of CRISPR technologies may lead to adverse outcomes which may not present themselves until later in life, or potentially even in subsequent generations. These could ultimately lead to long-tail and potentially high liability claims.26 The uncertainty and long gestation of potential adverse outcomes may well see insurers seeking to limit CRISPR-related coverage to pharma and med tech companies.24

The costs of gene therapyThe personalised therapy approaches for diseases such as HIV and Alzheimer’s offered by CRISPR technology comes at a cost, and potentially considerable cost. At a period of stress on healthcare budgets across the world, the opportunity costs of such therapeutics have to be assessed.

Were CRISPR to prove successful in making inroads into genetic diseases, this could impact aggregate life expectancy, and have a material influence on life, disability or longevity portfolios of insurance companies.

Medical malpracticeWherever in the life of a human, the manipulation of the gene can have, besides the wanted, some unwanted effects. This is an especially sensitive topic when it comes to fetus, embryos, newborns or children. CRISPR based interventions following fertility treatments, respectively in young children with e.g. diagnosis of a genetic disease are exposed to medical malpractice claims. Not only doctors or hospitals would be concerned, but also technology suppliers. Latter with the allegation of not having properly instructed medical professionals about the use of their product.

Conclusions

The FDA is likely to approve CRISPR mediated blood stem cell therapy anytime soon. Moreover, the first large gene drive trial with mosquitos is taking place in 2017; and results are expected from the first human trial on CRISPR mediated T-cell therapy in China. All this might lead in the next decade to new promising cell therapy approaches, T-cell and stem cell therapy and many significant inroads into currently devastating diseases. Due to its more relaxed legal environment, China might become the leading hotspot of CRISPR mediated gene manipulation.

While CRISPR technology clearly offers the potential to precisely treat human genetic diseases with cell therapy approaches, it will bring several ethical concerns that society will need to address quickly. CRISPR technology will doubtlessly have a massive impact on human society, including the insurance industry. The key question will be how ready we are for this fast moving technology.

Insurance risks around CRISPR include biohacking, long-tail side effects, the cost of treatment and material changes to health and longevity risk pools.

2017 will be a significant year in the progress of CRISPR technologies; and its potential for change must be more widely acknowledged.


References1 RM Blaese et al (1995). T Lymphocyte-Directed Gene Therapy for ADA− SCID: Initial Trial

Results After 4 Years. Science; 270(5235): 475–480.2 CE Thomas et al (2003). Progress and problems with the use of viral vectors for gene

therapy. Nature Reviews Genetics; 4: 346–358.3 AC Komor et al (2017). CRISPR-Based Technologies for the Manipulation of Eukaryotic

Genomes. Cell Review; 168: 1–17.4 KA Schaefer et at (2017) Unexpected mutations after CRISPR-Cas9 editing in vivo.

Nature Methods; 14(6): 547–548.5 R Jaenisch et al (2017). Generating CRISPR mouse models: Challenges and solutions.

Science Webinar Series; May 17, 2017.6 H Wang et al (2013). One-Step Generation of Mice Carrying Mutations in Multiple Genes

by CRISPR/Cas-Mediated Genome Engineering. Cell; 153: 910–918.7 KA Schaefer et al (2017). Unexpected mutations after CRISPR-Cas9 editing in vivo.

Nature Methods; 14(6): 547–548.8 Wang et al (2014). CCR5 Gene disruption via Lentiviral Vectors Expressing Cas9 and

Single Guided RNA Renders Cells Resistant to HIV-1 Infection. PLOS ONE; 9(12): 1–26.9 LJ Rupp et al (2017). CRISPR/Cas9-mediated PD-1 disruption enhances anti-tumor

efficacy of human chimeric antigen receptor T cells. Scientific Reports; 7(373): 1–10.10 G Schwank et al (2013) Functional Repair of CFTR by CRISPR/Cas9 in Intestinal Stem

Cell Organoids of Cystic Fibrosis Patients. Cell Stem Cell; 13: 653–658.11 Pini et al (2017). Genome Editing and Muscle Stem cells as a Therapeutic Tool for

Muscular Dystrophies. Curr Stem Cells; 3: 137–148.12 R Jaenisch et al (2017). Generating CRISPR mouse models: Challenges and solutions.

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(www.cbinsights.com/blog/crispr-startups-to-watch)14 J Champer et al (2016). Cheating evolution: engineering gene drive to manipulate the fate

of wild populations. Nature Reviews; 17: 146–159.15 N Subbaraman (2011). Science snipes at Oxitec transgenic-mosquito trial. Nature

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16 A Edney (5 August 2016). Gene-Engineered Mosquito Trial Cleared by FDA for Florida State. Bloomberg; (https://www.bloomberg.com/news/articles/2016-08-05/ gene-engineered-mosquito-trial-cleared-by-fda-for-florida-start).

17 B Owens (2017). Behind Zealand’s wild plan to purge all pests. Nature News; 541: 148–150

18 AM Moreno et al (2017). Therapeutic genome engineering via CRISPR-Cas system. WIREs Syst Biol Med; e1380(10.1002): 1–14.

19 D Cyranoski (15 November 2016). CRISPR gene-editing tested in a person for the first time. Nature News.

20 S Reardon (22 June 2016). First CRISPR clinical trial gets green light form US panel. Nature News.

21 DP Dever et al (2016) CRISPR/Cas9 beta-globin gene targeting in human haematopoietic stem cells. Nature; 539: 384–389.

22 Reuters: http://www.reuters.com/article/us-gene-editing-crispr-idUSKBN13300A23 UNESCO. UNESCO panel of experts calls for ban on “editing” of human DNA to avoid

unethical tampering with hereditary traits. (http://en.unesco.org)24 University of Minnesota: http://www.mbbnet.umn.edu/scmap.html25 Greenfield et al (2016). Genome editing – an ethical review.

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Anti-crop Bioweapons: An EU Perspective on Agroterrorism. Springer; 31–60



AuthorsDr Thomas Wildhaber is an Analyst in the Swiss Re Group Finance department. During an internal rotation, he investigated the impact to the insurance industry of the new CRISPR technology. Prior to joining Swiss Re, he was worked for a consulting company, where he was involved in projects for the pharmaceutical industry. He has a PhD in molecular biology from the ETH Zurich, Switzerland.

Séverine Rion Logean leads Swiss Re’s Life & Health R&D Europe unit. Her team provides cutting-edge R&D and applied expertise in morbidity and mortality/ longevity trends, incl novel diagnostics, pharmaceuticals and genetics. Séverine further explores new data sources and smart analytics driving digital innovation within Swiss Re. She has been leading consumer research in the field of ageing and supports consumer centric product development. Before joining L&H R&D, Séverine worked as a Senior Casualty Risk Engineer for Swiss Re in the fields of pharma, life sciences and hospital risk management. Prior to joining Swiss Re, Séverine worked in public pharmacies. She studied pharmacy at the Swiss Federal institute of Technology (ETH) in Zurich and the Ecole de Pharmacie in Lausanne to obtain her Federal Degree in Pharmacy.

Dr Christoph Nabholz is Head of R&D Life & Health in Swiss Re Group Underwriting. His team provides innovative and market-leading population trend research addressing the impact of technology, medical advances and human behaviour on health and mortality. Before joining the L&H R&D team he headed Business Development at the Swiss Re Think Tank, Centre for Global Dialogue. He joined Swiss Re in 2002 in Global Life & Health Underwriting where he served as Swiss Re’s Global Genetics Consultant. Prior to joining Swiss Re, he was a postdoctoral fellow in genomics and functional genetics at Harvard University and has a PhD in molecular genetics from the University of Fribourg, Switzerland.

The Risk Dialogue Series of the Swiss Re Institute is designed to inform readers about ongoing debates and discussions between Swiss Re and the stakeholders of risk and insurance business issues.

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Editor: Simon Woodward, Swiss Re Institute

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