reference standards to support the development of biosimilars · 2018-04-02 · reference standards...
TRANSCRIPT
Reference Standards to Support the
Development of Biosimilars
Jane Robinson & Adrian Bristow
Jane.Robinson @nibsc.org [email protected]
The National Institute for Biological Standards and Control, UK
www.nibsc.org
CMC Strategy Forum 15 – 16 July 2013 Gaithersburg, USA
Reference Standards to Support the Development of Biosimilars
What is a biosimilar?
EMA ……. a biological medicine that is developed to be similar to an existing
biological medicine (the ‘reference medicine’). …….. The active substance of a
biosimilar and its reference medicine is essentially the same biological substance,
though there may be minor differences due to their complex nature and production
methods. EMA/837805/2011
FDA …. a biological product that is highly similar to an already approved biological
product, notwithstanding minor differences in clinically inactive components, and for
which there are no clinically meaningful differences between the biosimilar and the
approved biological product in terms of the safety, purity, and potency. FDA NEWS
RELEASE Feb. 9, 2012
How does the development of biosimilars impact the requirement for, and provision
of, public reference standards?
• How have things been done previously?
• What factors are different for biosimilars?
CMC Strategy Forum July 2013
Public Reference Standards – Sources (1)
NIBSC produces >95% of the International Standards
>600 catalogue items
>125,000 ampoules/vials distributed per year to >60 countries
www.nibsc.org/products.aspx
WHO establishes International Biological Standards
which define the unit of activity for a biological
The National Institute for Biological Standards and Control is its principal
collaborating laboratory in this activity.
(NIBSC is a centre of the Medicines and Healthcare Products Regulatory
Agency, UK, since 01 April 2013)
www.who.int/bloodproducts/catalogue/en/
CMC Strategy Forum July 2013
WHO International Standards & Reference Reagents & NIBSC
Reference Reagents
CMC Strategy Forum July 2013
Examples of particular relevance to biosimilar development:
code
Erythropoietin, Human Recombinant (2nd WHO International Standard) 88/574
Follicle Stimulating Hormone, Human, Recombinant for bioassay (1st WHO International
Standard) 92/642
Follicle Stimulating Hormone and Luteinizing Hormone, Human Urinary, for bioassay (4th
WHO International Standard) 98/704
Granulocyte Colony Stimulating Factor rDNA (WHO 2nd International Standard) 09/136
Granulocyte Macrophage Colony Stimulating Factor rDNA (WHO 1st International
Standard) 88/646
Growth Hormone, Human, Pituitary (1st WHO International Standard) 80/505
Heparin, Low Molecular Weight (WHO 2nd International Standard) 01/608
Insulin, Human (1st WHO International Standard) 83/500
Interferon alpha 2a rDNA (WHO 2nd International Standard) 95/650
Interferon alpha 2b rDNA (WHO 2nd International Standard) 95/566
Interferon beta rDNA (WHO 3rd International Standard) 00/572
Interferon beta Ser17 rDNA (NIBSC Reference Reagent) 00/574
Interleukin-2 Cell line derived (WHO 1st International Standard) 86/504
Interleukin-11 rDNA (WHO Reference Reagent) 92/788
Luteinizing Hormone, Human, recombinant (1st WHO International Standard) 96/602
Parathyroid Hormone, Human, recombinant (1st WHO International Standard) 95/646
Prolactin Human, recombinant, glycosylated (1st WHO Reference Reagent) 98/580
See: Thorpe & Wadhwa, 2011 Biologicals 39(5):262-5
Public Reference Standards – Sources (2)
National and regional organizations such as the pharmacopoeias, for
example United States Pharmacopeia and European Pharmacopoeia,
establish reference standards for bio-pharmaceuticals
www.usp.org/reference-standards/find-reference-standard
crs.edqm.eu/db/4DCGI/web_catalog_CRS
Comparison of WHO and pharmacopoeial biological standards:
differences in form and scope
(some exceptions. eg somatropin, heparin mol wt calibrants)
CMC Strategy Forum July 2013
Two approaches to standardizing the same bio-pharmaceutical
THE SECOND INTERNATIONAL STANDARD
FOR ERYTHROPOIETIN, RECOMBINANT
NIBSC Code: 88/574
THE Ph. Eur. BRP for ERYTHROPOIETIN
1ug EPO 250ug EPO
Protein-containing formulation Protein-free formulation
Supports Bioassays Supports Bioassays and physico-chemical assays
Primary standard, defining unit
Where content in activity units is assigned, are usually
secondary standards, defined in in terms of IS using
compendial methodology
Only a few exceptions (eg somatropin, some
vaccines), where content is defined in SI, and
may be considered primary standard.
Where content in SI is assigned, are usually true
primary standards value assigned using a reference
method
Secondary standard, with the unit traceable to
the WHO IS
Previous route for development of an International Standard
1. International Standards (IS) and units of bioactivity were
established for naturally occurring biological molecules
2. The first generation of recombinant bio-therapeutic products were
recombinant DNA versions of naturally occurring molecules such
as insulin, growth hormone, interferons, erythropoietin, etc
3. Usually, separate International Standards for the recombinant DNA
versions were established, with the unit in some way traced or
related to the previous “natural” IS
4. Recombinant therapeutic products were traced to the new
recombinant IS’s
CMC Strategy Forum July 2013
1st IS for EPO
(Human urinary
extracted)
1st IS for EPO
(recombinant)
2nd/3rd IS for EPO
(recombinant)
Early R & D
Product
development
First recombinant
products
First Pharmacopoeial
standards
Pharmacopoeial
standards
Recombinant
products
Route of development of reference standards for erythropietin
What needs to be considered with biosimilars?
1) Comparison with the originator product.
Particularly for physicochemical analytical techniques, need to demonstrate capability of
the system to detect differences.
For biological activity, need to compare originator and biosimilar to common reference
standard “…. international or national standards and reference reagents should be used
to determine the potency and to express results in IU or U…….” WHO Expert Committee
on Biological Standardization, Geneva, 19 to 23 October 2009 Guidelines on Evaluation of
Similar Biotherapeutic Products (SBPs)
2) Many will be “next generation”, modified molecules: Biosynthetic structural variants
Chemically derivatized natural molecules (eg pegylated)
“Natural” molecules with no natural equivalent (monoclonal antibodies)
Artificial constructs which don’t exist in nature (receptor-Fc fusion proteins)
Unlike the first generation of biotherapeutics, these biological molecules do not exist in nature.
There are no pre-existing standards: they cannot be standardized until after drug discovery.
The products get to the market without the existence of WHO standards, or traceability to an
international unit.
CMC Strategy Forum July 2013
Biosimilars – importance of the issue
Growth predicted in
• Number of products
• Market volume and share
• Geographical distribution production and marketing
Biosimilar monoclonal antibodies (mAbs) and insulins likely to see the fastest
growth
Emerging markets, especially China and India, currently account for majority of
revenue
Growth in developed markets expected with patent expiries on earlier biologics in
next few years
Recent report: Biosimilars And Follow-On Biologics: World Market 2013-
2023, Visiongain, published April 2013
WHO have recognised the need for global standardisation of biosimilar
products (WHO technical report series, 56th report, 941 : 12-13, 2007).
CMC Strategy Forum July 2013
Biosimilars in Europe
Biosimilars approved by EMA
Product Name Active Substance Authorisation Date
Abseamed epoetin alfa 28 Aug 2007
Binocrit epoetin alfa 28 Aug 2007
Biograstim filgrastim 15 Sep 2008
Epoetin alfa Hexal epoetin alfa 28 Aug 2007
Filgrastim Hexal filgrastim 6 Feb 2009
Filgrastim
ratiopharm
filgrastim 15 Sep 2008
Withdrawn 20 Apr 2011
Nivestim filgrastim 8 Jun 2010
Omnitrope somatropin 12 Apr 2006
Ratiograstim filgrastim 15 Sep 2008
Retacrit epoetin zeta 18 Dec 2007
Silapo epoetin zeta 18 Dec 2007
Tevagrastim filgrastim 15 Sep 2008
Valtropin somatropin 24 Apr 2006
Withdrawn 10 May 2012
Zarzio filgrastim 6 Feb 2009
Data from GaBI Online updated 10 May 2013
Biosimilars under review by EMA
Active Substance
Number of
applications
Originator
product
Filgrastim 1 Neupogen
Follitropin alpha 2 Gonal-F
Infliximab 2 Remicade
Data from GaBI Online, data collected 11 April 2013
CMC Strategy Forum July 2013
Biosimilars in Europe
28 June 2013 EMA/390722/2013 Press Office
Press release
European Medicines Agency recommends approval of first two monoclonal antibody biosimilars Recommendation marks extension of biosimilar concept to new product-class …………………….. Remsima and Inflectra both contain the same known active substance, infliximab. In the application dossiers, they have been shown to be similar to the biological medicine Remicade, a monoclonal antibody that has been authorised in the European Union since 1999…………………………. http://www.ema.europa.eu/docs/en_GB/document_library/Press_release/2013/06/WC500144941.pdf
CMC Strategy Forum July 2013
Biosimilar monoclonal antibodies
Earliest mAbs are coming off patent
Biosimilar mAbs will have exact amino acid sequence but different manufacturing
clone/process resulting in micro variations which might effect PK, PD and potency Biosimilar trastuzumab produced in tobacco plants by PlantForm, 2013
Biosimilar palivizumab (2012) & rituximab (2011) produced in non-transgenic green plants by iBio
Complexity of the molecules means that it is not possible to produce exact copies
of innovator mAbs. Concerns have been raised by WHO over their quality and
safety.
In addition there are examples of falsified and counterfeit mAb products being
marketed
CMC Strategy Forum July 2013
Slide courtesy of Simon Hufton, NIBSC
Are potency standards needed…….
…… when products are labelled and dosed by mass ?
Yes: biological activity measured in a bioassay is included in the
specification. Potency is measured against a reference standard.
“…. international or national standards and reference reagents should be used
to determine the potency and to express results in IU or U…….” WHO Expert
Committee on Biological Standardization, Geneva, 19 to 23 October 2009
Guidelines on Evaluation of Similar Biotherapeutic Products (SBPs)
Two products are shown to have similar biological activity by reference to a
common standard.
A comparator product is not a reference standard.
CMC Strategy Forum July 2013
Are product-specific potency standards needed….
…….. for next-generation biotherapeutics (whether biosimilar or originator) if an
International Standard already exists for the “parent” molecule?
CMC Strategy Forum July 2013
Activity of modified molecule may differ from parent molecule
Comparison of the IS for G-CSF (filgrastim) with G-CSF product & 2 pegylated G-CSF
products, GNFS-60 bioassay
Figure courtesy of Chris Bird, NIBSC
CMC Strategy Forum July 2013
Method-specific potencies
2D9 cell antiviral assay
1 10 100 10000.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
95/650
RR
Dilution
Ab
so
rb
an
ce
ISRE SEAP RGA
1 10 100 10000.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
2.75
3.00
3.25
3.50
3.75
4.00
4.25
95/560
RR
Dilution
Ab
so
rb
an
ce
Comparison of 95/650 IFN-α2a standard and a peg-IFN-α2a product B in antiviral- and reporter gene- assays:
In this case, defining the unit of the pegylated interferon product in term of
the parent interferon molecule would give method-specific potency
estimates
Figure courtesy of Tony Meager,
formerly NIBSC
CMC Strategy Forum July 2013
Are product-specific potency standards needed….
“Blood products” have a substantial history with these issues
Natural, recombinant & modified products ……example: Factor VIII
products: plasma derived (> 30 products)
recombinant full-length (4 products)
B-domain-deleted recombinant (reduce immunogenicity)
(1 product)
in development: full length/B-domain-deleted pegylated/Fc-fusion (increase ½ life)
So far, have not used biosimilar route
Data courtesy of Elaine Gray, NIBSC
CMC Strategy Forum July 2013
Are product-specific potency standards needed….
PRODUCT vs WHO IS
VALID parallel / linear
INVALID non-parallel / non-linear
BY 1 METHOD BY ALL METHODS ASSAYS POSSIBLE ASSAYS IMPOSSIBLE
USE
METHOD
TO LABEL
IU
NO
DISCREPANCY
LABEL BY
EITHER
METHOD
IU
DISCREPANCY PRODUCT-
SPECIFIC
STANDARD product-specific
units
NEW
METHODS LABEL
BY MASS
SELECT
SINGLE
METHOD
IU
PRODUCT-
SPECIFIC
STANDARD product-specific
units
See similar decision tree: “Recommendations on the potency labelling of factor VIII and factor IX concentrates”
J Thromb Haemost 2013; 11: 988–9.
& / or
CMC Strategy Forum July 2013
Are product-specific potency standards needed….
Note: If the relative potency determination requires
specification of a particular method, the method may need to be
very tightly defined and controlled
For a biosimilar for which a potency standard of the same molecular
form exists, the standard should be demonstrated to be suitable in the
range of potency assays used
For biosimilars which are modified molecules, it may be analytically
possible to define the unit in terms of an existing standard of the parent
product in some cases
but
these molecules are designed to have different activities in man
use of the same units could be clinically misleading
CMC Strategy Forum July 2013
EMA Draft for consultation
EMA/CHMP/BWP/85290/2012 End of consultation 1 October 2013
Guideline on the declaration of the quantitative composition / labelling of biological
medicinal products that contain modified proteins as active substance
The strategy for declaring the quantitative composition that would be acceptable for a
product containing a modified protein will likely have to be considered on a case-by-
case basis. Therapeutic proteins constitute a large number of products applied in a wide
range of therapeutic areas and as such it may be difficult to follow a “one fits all
approach”. Three different situations are envisaged:
• Product labelling in mass units
• Product labelling in “in-house units”, i.e. the unitage is product specific
• Product labelling in International Units
CMC Strategy Forum July 2013
Specifications for biological therapeutics include a range of attributes
requiring physico-chemical analyses. These, typically, include
Size
Charge
Amino-acid
composition
Sequence
Glycosylation
SDS-PAGE, Size –exclusion HPLC, Mass Spectroscopy
Ion exchange HPLC, Capillary electrophoresis, non-
denaturing PAGE
Reverse Phase HPLC
Peptide mapping
Glycan analysis, Capillary electrophoresis
Reference standards to support method validation
and system suitability criteria
CMC Strategy Forum July 2013
Reference standards to support method validation
and system suitability criteria
For biosimilars, need to meet specifications and demonstrate similarity to originator
product.
Consider a size exclusion test
for dimers and aggregates.
If the reference material and
test samples look like this:
min2 4 6 8 10 12 14 16 18
mAU
0
50
100
150
200
250
300
350
MWD1 E, Sig=280,16 Ref=360,100 (USP GCSF\P168000001.D)
9.9
02
• Are all samples entirely monomers?
• Is the system incapable of resolving monomers, dimers and
aggregates?
• Are the dimers and aggregates below the limit of detection of the
system?
Need to test system with impurities under investigation
CMC Strategy Forum July 2013
System validation reagents are often provided by treating the CRS using
defined procedures
-Oxidised products Hydrogen peroxide or chloramine-T treatment
-Aggregates Agitation or heat treatment
-Deamidation High pH treatment
Such procedures:
- are non-defined and irreproducible (“vortex for about 30s)
- are one of the most frequent sources of “it doesn’t work” user-feedback
- Cannot support defined limits of detection
Reference standards to support method validation
and system suitability criteria
The need to support validation of the method performance
and system suitability criteria
min2 4 6 8 10 12 14 16 18
mAU
0
50
100
150
200
250
MWD1 E, Sig=280,16 Ref=360,100 (USP GCSF\P168000003.D)
9.2
70
10.0
40
11.9
84
dimer
oligomer
min2 4 6 8 10 12 14 16 18
mAU
0
20
40
60
80
100
120
140
MWD1 E, Sig=280,16 Ref=360,100 (USP GCSF\P173000014.D)
If the prescribed system
suitability test (70degC,
1h) produces this, it isn’t
much use
Returning to the size exclusion test for dimers and aggregates:
CMC Strategy Forum July 2013
Reference standards to support method validation
and system suitability criteria
min2 4 6 8 10 12 14 16 18
mAU
-20
0
20
40
60
80
100
MWD1 E, Sig=280,16 Ref=360,100 (MR\P184000025.D)
5.74
8
9.37
6
10.25
6
min2 4 6 8 10 12 14 16 18
mAU
-16
-14
-12
-10
-8
-6
-4
MWD1 E, Sig=280,16 Ref=360,100 (MR\P184000025.D)
5.748
9.376
10.25
6
This preparation was prepared by
controlled chemical cross-linking,
thermal aggregation, and
reformulation
It is freeze-dried, apparently stable,
and could have assigned identities
and quantities
Normalised
Expanded
• A reference material which is similar to drug substance can serve to identify and quantify
the drug substance in the sample.
• Additional molecular entities are required to identify and quantify impurities and
demonstrate system suitability
• Drug substance spiked with characterized impurities can serve multiple functions
Reference standards for physicochemical analytical
methods
CMC Strategy Forum July 2013
Reference standards to support method validation
and system suitability criteria
Test Standard Function Replaces
Size –
exclusion
HPLC
Stable dimerized
preparation
Demonstrate column performance
(separation and/or Limit of detection)
Defined method:
Agitation/heat treatment
methods
Ion-exchange
HPLC
Deamidated
preparation
Demonstrate column performance
(separation and/or Limit of detection)
Defined method: High pH
treatment
Reverse
Phase HPLC
Oxidised
preparation
Demonstrate column performance
(separation and/or Limit of detection)
Defined method: Hydrogen
peroxide treatment
Peptide
mapping
Single amino-
acid mutants
Target peptides
Demonstrate system resolution
Support quantitative applications
Nothing
Nothing
Glycan
analysis
Glycan
preparations
High/Low pI
preparations
Demonstrate system resolution
Support quantitative applications
of Z number
Test substance
Nothing
Glycoprotein glycan reference standards
Glycosylation patterns - determined by the producing cell line, growth and
purification conditions, rather than the introduced gene.
Analysis - usually by cleavage of the glycan chains from the protein backbone
Analysis is independent of protein backbone
There is a heterogeneous mixture of glycans
The glycan mix can be profiled by chromatographic, electrophorectic or MS analyses
Proposed USP glycan standards –developed in collaboration with NIBSC
Four mixtures of different types of glycan, designed to cover different groups of
recombinant proteins
The analytical method should be able to resolve this mixture into (at least) the specified
number of components with appropriate relative amounts.
Suitable methods are given in (draft) USP chapter <212>, but……..
Usage of the standard should be independent of the analytical method
CMC Strategy Forum July 2013
Glycan reference standard
HPLC separation of fluorophore-labelled glycan standards of proposed USP standards relevant to mAbs
Figure courtesy of Chris Jones, NIBSC
Three dimensional structural similarity?
Folding and three dimensional structural integrity:
• Often analysed by circular dichroism or Fourier transform infra-red
• Often not clear whether minor differences are significant
• Replace subjective visual comparison with statistical approach
• Use a reference standard (eg. one protein spiked with varying amounts of
another) to understand when spectra are significantly different.
071004b2.xls. Stability study: Near UV region. Comparison Week 1 vs. Week 2.
-10
-8
-6
-4
-2
0
2
4
6
8
10
250 270 290 310 330 350
Wavelength/nm
Inte
ns
ity
/Cd
[m
de
g]
2%
0%
100%
4%
CMC Strategy Forum July 2013
Logistical issues in development of public reference standards for
biosimilars
• Identification of requirement, selection of types of material(s)
- data contribution & collation
• Decision to proceed - cooperation, coordination, harmonization, MoUs
• Procurement of materials - drug material : drug manufacturers, originator/biosimilar
impurities, fragments, other moieties – manufacturers/other
laboratories
(potency 1ug drug per vial? Physiochemical 10-50 ug ?)
• Processing development - utilizing (usually extensive) existing data
• Processing, testing
• Collaborative study - time and effort should not be underestimated
• Agreement on outcome
• Storage, distribution - cost and infrastructure
CMC Strategy Forum July 2013
Reference standards for biosimilars
In conclusion
The need for reference standards to support development of biosimilars has already arrived
and is expected to increase rapidly
This requires additional and different types of reference materials from those required
previously
A cooperative, structured approach and harmonization will benefit all
WHO and pharmacopeias will need to modify and adapt their current approaches to meet the
changing requirements
Guidance and feedback from regulators will help focus efforts appropriately
Progress will depend on input from manufacturers and CROs: information on anticipated
requirements, materials, data on materials, contribution to testing candidate standards
CMC Strategy Forum July 2013