giuseppe fornarini, u.o. oncologia medica 1 ospedale ... · trattamenti della malattia con...

Giuseppe Fornarini,

U.O. Oncologia Medica 1

Ospedale Policlinico San Martino

IRCCS Genova

Trattamenti della malattia con mutazioni di BRCA e altro…

Background

• Prostate cancer is inheritable…but

• Important to know the family history

• A different type of genes are involved…BRCA1/2,

Lynch Syndrome…others

• Pts with BRCA2 mutation have 3-9x risk of PC and

more lethal

• Germline could be different from somatic mutation

• In advanced disease clinical management does not

differ

• To whom should we offer germline genetic testing

and when… because

To whom should we offer germline genetic testing?

Presented By Heather Cheng at 2018 ASCO Annual Meeting

Germline pathogenic alterations may have both familial and therapeutic implications

More recent genetic findings in advanced PC may also inform therapy


Outline

• The 6 DNA repair pathways

• Prevalence of DNA repair defects in prostate cancer

• DNA repair and therapeutic implications

– PARP inhibitors

– Hormonal therapy

– Immune checkpoint inhibitors

– Platinum chemotherapy

Emmanuel S. Antonarakis, MBBCh

Single-Stranded (ss)DNA Repair Pathways

• Mismatch repair

– Base errors from DNA replication and recombination

– MSH2, MSH6, MLH1, PMS2

• Nucleotide excision repair

– DNA damage from UV light, polycyclic aromatic hydrocarbons

– XPA-G, ERCC1-8, CSA/B, RPA, RAD23A/B

• Base excision repair

– DNA damage from alkylation, oxidation/ROS, deamination

– PARP1/2/3, POLβ, MUTYH, XRCC1, MBD4, NTHL1

Mateo J, et al. Eur Urol. 2017;71:417-425. Emmanuel S. Antonarakis, MBBCh

Double-Stranded (ds)DNA Repair Pathways

• Homologous recombination

– DNA damage from ionizing radiation or other dsDNA injury

– FANC genes, BRCA1/2, ATM, PALB2, RAD50, RAD51, NBN, GEN1, MRE11, BLM, ATR

• Nonhomologous end joining

– DNA damage from ionizing radiation or other dsDNA injury

– XRCC4/5/6, LIG4, DCLRE1C, PRKDC, NHEJ1, POLL/M

• Translesion DNA synthesis

– Error-prone recovery mechanism when no DNA template

– POLH, POLI, POLK, PCNA, REV1/3 (error-prone DNA polymerases)

Mateo J, et al. Eur Urol. 2017;71:417-425. Makridakis NM, et al. Front

Genet. 2012;3:174. Emmanuel S. Antonarakis, MBBCh

• 11.8% (82/692) of men with metastatic prostate cancer inherited a germline DNA repair mutation vs 4.6% of 499 men with localized disease

Germline Mutations in Prostate

Cancer: 1 in 10

Pritchard CC, et al. N Engl J Med. 2016;375:443-

453.

Distribution of Presumed

Pathogenic Germline

Mutations

PALB2

4%

RAD51D

4%

ATR 2% NBN 2%

PMS2 2% GEN1 2%

MSH2 1% MSH6 1%

RAD51C

1% MRE11A

1% BRIP1 1% FAM175A

1%

BRCA2

44%

ATM

13%

CHEK2

12%

BRCA1 7%

Gene No. of Mutations

% of Men

BRCA2 37 5.35

ATM 11 1.59

CHEK2* 10 1.87

BRCA1 6 0.87

Presumed Pathogenic Germline

Mutations

in Metastatic Cases (N = 692)

*n = 534; data censored for metastatic cases with inadequate sequencing.

• Germline mutations in 14% (21/150) of men with recurrent/advanced prostate cancer

• Men with intraductal/ductal histology more likely to have germline mutations

Association Between Germline DNA-Repair Defects and Intraductal/Ductal

Histology

Isaacsson Velho P, et al. The Prostate. 2018;[Epub ahead of print].

Intra/Ductal Histology

No Intra/Ductal

Histology

P Value*

40% (10/25) 9% (11/125) P = .003

*Fisher’s test.

Incidence of Pathogenic Germline

Mutations

Distribution of Pathogenic

Germline Mutations CDH1 5%

MSH6 5%

PALB2 5%

NBN 5%

BRCA2 43%

CHEK2 14%

ATM 14%

BRCA1 9%


Effect of DDR Mutation on Treatment Responses

Presented By Carmel Pezaro at 2018 ASCO Annual Meeting

Selected Trials for mCRPC with Relevance to DNA repair defects


PARP Biology

• A key role in the repair of ssDNA breaks via BER pathway

• Binds directly to sites of DNA damage

• Once activated, uses NAD as a substrate to add large, branched chains of poly(ADP-ribose) polymers (ie, PARylation) to itself and interaction partners

• Recruits other DNA repair enzymes to site of damage

Ohmoto A, et al. Onco Targets Ther. 2017;10:5195-5208.

DNA damage

NAD+ Nicotina

mide +

pADPr

Lig3 XRCC1

Polß PNK

PARP


PARPi Leads to Increase in dsDNA Breaks

• Inhibition of PARP: – Prevents

recruitment of DNA repair enzymes to ssDNA breaks, or traps PARP on DNA

– Leads to failure of ssDNA repair and accumulation of ssDNA breaks

– Replication fork is arrested at damage, produces dsDNA breaks

Ohmoto A, et al. Onco Targets Ther. 2017;10:5195-5208.

PARP

During S-phase, replication fork is

arrested at site of ssDNA breaks

Degeneration into

dsDNA breaks

ssDNA

breaks PARP

inhibition

XRCC1

DNA Lig III

PNK 1

DNA Polβ


Synthetic Lethality Hypothesis

Farmer H, et al. Nature. 2005;434:917-921. Bryant et al. Nature. 2005;434:913-917.

Repair, Survival

Repair, Survival

Normal cell Non-BRCA mutation carrier

PARP function BRCA function

PARP inhibitor


DNA damage

Repair, Survival

Repair, Survival

Normal cell BRCA mutation carrier

(1 allele lost)


PARP inhibitor


DNA damage

Repair, Survival

Cell Death

Cancer cell BRCA mutation carrier

(both alleles lost)


PARP inhibitor

DNA damage



TOPARP


TOPARP Results: Response


TOPARP Results


Single Agent Trials In Progress


Combination Trials In Progress


Clinical Data Extrapolations


DNA Repair Defects and Hormonal Therapy

Abiraterone in mCRPC With HR Deficiency

• 20/80 (25%) evaluable pts with mCRPC had DNA repair defects

Hussain M, et al. J Clin Oncol. 2017;[Epub ahead of print].

PFS by DRD Status DNA Repair Defects*

BRCA2

ATM

BRC

A1 RAD5

1B RAD51

C PALB2

FANCA

Frameshi

ft

Nonsens

e

Not

detected

In-frame

indel

Copy-neutral

LOH

Missense

+ Censored

Log-rank P = .0254

Median, Mos (95%

CI)

DRD: 14.5 (11.0-

19.5)

WT: 8.1 (5.5-11.0)

Pro

bab

ilit

y o

f P

FS

Mos

0.2

0.4

0.6

0.8

1.0

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42

20 19 13 6 4 3 2 1 20 43 34 20 10 5 3 0 60

DRD WT

Pts at Risk, n

*Data shown for 25 of 80 pts with exploratory tumor sequencing.

Biallelic Monoallelic

2 copy

losses

1 copy

loss


Abiraterone or Enzalutamide and HR Deficiency

PFS by DRD Status

Antonarakis ES, et al. Eur Urol. 2018. In press.

PF

S (

%)

0 6 12 18 24

20

40

60

80

100

0

Any Mutation No Yes (other) Yes (ATM/BRCA1/BRCA2)

Mos

Yes (other)

Yes (ATM/BRCA1/ BRCA2)

Pts at Risk, n

150 102 60 38 18

13 9 6 4 3

9 8 6 4 3

No

OS by DRD Status

Any Mutation No Yes (Other) Yes (ATM/BRCA1/BRCA2)

OS

(%

)

20

40

60

80

100

0 0 6 12 18 24 30 36 42 48

Mos

Yes (other)

Yes (ATM/BRCA1/ BRCA2)

Pts at Risk, n

No 150 145 128 75 75 52 35 22 11

13 13 13 9 8 6 5 3 0

9 9 8 7 6 4 4 4 0


Abiraterone vs Enzalutamide and HR Deficiency

• Randomized phase II crossover study in treatment-naive pts with mCRPC (N = 202)

• BRCA2- or ATM-truncating mutations or rearrangements:

– Somatic (ctDNA): 6/115 (5.2%)

– Germline (WBC): 8/202 (4.0%)

• Monoallelic BRCA2 or ATM deletion in 21 pts

– No TTP differences (P = .205)

Annala M, et al. Cancer Discov. 2018;[Epub ahead of print].

Time to Progression by

HRR Status*

*Abiraterone + enzalutamide arms combined.

8

2

6

6

4

1

2

9

1

4

5 3 1 1

0

5

6

2

3

3

1

7

8 5 2 0 1

4

2 0 0 0 0 0 0

Pts at

Risk, n

Pro

bab

ilit

y o

f P

FS

0 4 8 1

2 1

6

2

0 2

4

2

8

0.

2

0

0.

6

0

.

4

1.

0

0

.

8

Mos

HR P Value

PSA > 40 ng/mL 1.50 .032

LDH > ULN 1.87 .008

ALP > ULN 1.16 .496

Hemoglobin < 130 1.45 .055

Visceral mets 2.27 .004

ECOG PS 2 1.26 .327

ctDNA > 2% 1.44 .086

HRR defect 5.27 < .001

HRR defect Yes No ctDNA unquantifiable


DNA Repair Defects and Immune Checkpoint Inhibitors

KEYNOTE-016: Responses to Pembrolizumab in MMR-Deficient

Tumors • Radiographic responses across 12 tumor types at 20 wks (N = 86)

Le DT, et al. Science. 2017;357:409-413.

Ampulla of Vater

Cholangiocarcinoma

Colorectal

Endometrial cancer

Gastroesophageal

Neuroendocrine

Osteosarcoma

Pancreas

Prostate

Small Intestine

Thyroid

Unknown primary

100

50

0

-50

-100 C

han

ge F

rom

Baseli

ne S

LD

(%

)

Prostate

Prostate

(n = 1)


MMR Mutations in mCRPC

• 4/150 (2.7%) mCRPC pts were MSI-high, 3 of whom had MMR mutations (2%) – 13 mut/Mb (Pt #149) –

MSH2

– 21 mut/Mb (Pt #147) – no MMR mutation

– 23 mut/Mb (Pt #148) – MSH2

– 25 mut/Mb (Pt #150) – MSH2 and MLH1

Robinson D, et al. Cell. 2015;161:1215-

1228.

MSI Analysis:

Hypermutated vs

Nonhypermutated CRPC

Fra

cti

on

Un

sta

ble

Lo

ci

0 50

0 100

0

150

0

0.1

0 0

0.3

0 0.2

0

0.5

0 0.4

0

Nonsynonymous

Mutations

Negative

MSI Positive

149

147

148 150

32, 41, 49, 67,

93


MMR Mutations Can Cause HRD Mutations

• This patient should be treated with a PD-1 inhibitor, not a PARP inhibitor

Patient Case Gene Mutation

Primary MMR mutation MSH2 E809X* + LOH = MSI-high (> 100

mut/Mb)

Secondary DNA-repair mutations

BRCA2 ERCC4 ERCC5 FANCM MSH6

E1646fs* M361fs* E474fs* V1336fs* F1104fs*

*Protein truncation by stop codon (X) or frameshift (fs).


MMR Defects in Prostatic Ductal Carcinoma

• 4/10 (40%) had MMR mutations; 3/10 (30%) had MSI and hypermutation

Schweizer MT, et al. Oncotarget.

2016;7:82504-82510.

Pt No.

Ductal Component for NGS, %

Est. Tumor Content

From NGS, %

MMR Gene Alteration HR Gene Alteration Hyper-

mut

Total Coding Muts/1.2 Mb Sequenced

1 71 30 No CHEK2 c.1100delC + LOH No 4

2 45 40 MSH2 inversion No No 4

3 65 60 No No No 4

4 30

60 MSH6 c.1900_1901del + LOH No Yes 29

5 97 50 MSH2-GRHL2 rearrangement +

LOH No Yes 34

6 99 50 No No No 5

7 25 0 -- -- -- --

8 31 70 No No No 5

9 35 10 No BRCA2 c.594delT + likely LOH No 3

10 -- 60 MLH1 exon 19+ 3’UTR homozygous deletion

No Yes 32


MMR Defects and Gleason Grade

• 1.2% (14/1176) of primary adenocarcinomas and NEPC had MSH2 protein loss by IHC

• Pathology and MSH2 loss – Primary Gleason pattern 5

enriched for MSH2 loss: 8% (7/91)

– MSH2 loss in pts with any other Gleason score: < 1% (5/1042)

– P < .05

Guedes LB, et al. Clin Cancer Res.

2017;23:6863-6874.

Cases with MSH2

loss

Controls without

MSH2 loss P =

.008

CD

8 (

cell

s/m

m2)

1200

1000

800

600

400

200

0


DNA Repair and Platinum Chemotherapy

Platinum Response in mCRPC With HR Deficiency

Cheng H, et al. Eur Urol. 2016;69:992-

995.

Clinical Treatment Course Clinical Treatment Course

Pt Allele BRCA2 Mutation Mutation Type

1 1 c.9196C>T; p.Q3066X Premature stop

2 127 bp del in exon 11 Fs deletion

2 1 c.8904delC; p.V2969Cfs *7 Fs deletion

2 c.2611delT; p.S871Qfs *3 Fs deletion

3 1 Homozygous copy loss Copy loss

2 Homozygous copy loss Copy loss

Pt

2

PS

A (

ng

/mL

)

7

0 6

0 5

0 4

0 3

0 2

0 1

0 0 2012 2013 2014 2015

5 mos

ABI ENZ DOC CAR

+DOX

Pt

1

PS

A (

ng

/mL

)

50

0 4

0

0 30

0 2

0

0 10

0 0

2012 2013 2014

18 mos ABI

ENZ DOC CAR

+DOC

CAR

+DOC CIS

+ETO

30 mos

ABI CAR PA

C

CAR

+DOC

Pt

3

PS

A (

ng

/mL

)

1

2 1

0 8

6

4

2

0 2011 2012 2013 2014

CAR

+DOC

*

*Time of metastatic biopsy.

*

*


• Near-CR to cisplatin/docetaxel in a pt with metastatic NEPC, lasting 12 mos

– Genome of metastatic tumor found to be highly altered; germline FANCA mutation (S1088F) with somatic LOH also identified

– In preclinical studies, loss of FANCA associated with increased cisplatin sensitivity

10 0.01

Platinum Response in mCRPC With FANCA Deficiency

Beltran H, et al. JAMA Oncol. 2015;1:466-474.

Increased Cisplatin Sensitivity With Loss of

FANCA

Xenograft Model Cell Culture

Model 130 110 90 70 50 30 10 0 C

ell

Via

bil

ity (

%)

0.1 1.0 100 Cisplatin IC50 (μM)

FANCA KO2

Control

IC50

0.8 μM

2.5 μM

Control KO2

FANCA

GAPDH

800

600

400

200

0

1000

Tu

mo

r V

olu

me

(m

m3)

0 4 8 11 14 Days

Vehicle

Cisplatin


HR Deficiency and Response to Carboplatin

• 8/141 (5.7%) men with mCRPC had pathogenic germline BRCA2 variants

Pomerantz MM, et al. Cancer. 2017;123:3532-3539.

OS With

Carboplatin/Docetaxel by

BRCA2 Carrier Status

PSA Response With

Carboplatin/Docetaxel

by BRCA2 Carrier Status

*Carriers of pathogenic germline variants in other

DNA repair genes (MSH2, ATM, BLM, FANCA).

Observations (n=141)

BRCA2 carrier

BRCA2 noncarrier

Log-rank P = .03

Mos After Initiation of Carboplatin/Docetaxel

Pro

bab

ilit

y o

f O

S 1.00

0.75

0.50

0.25

0

0 12 24 36 48 60 72 84 96

Pts at Risk, n

BRCA2

noncarrier

BRCA2

carrier

133 51 14 6 5 3 2 1 1

8 5 3 3 2 2 0 0 0

BRCA2 carrier

BRCA2 noncarrier

*

*

* *

PS

A D

eclin

e (

%)

0

25

50

75

100


Conclusions

• Not all DNA repair lesions are created equal

• Somatic (and germline) DNA repair mutations are common in prostate cancer, particularly mCRPC

• HRD mutations may sensitize to PARP inhibitors, platinum agents

• MMR mutations may sensitize to immune checkpoint inhibitors

• The role of germline vs somatic, and single- vs double-copy inactivation, remains unclear


Grazie!!!!!

giuseppe fornarini, u.o. oncologia medica 1 ospedale ... · trattamenti della malattia con...

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