BRCA Mutation and PARP Inhibitors

Pancreatic cancer has a poor prognosis. Focused efforts in the development of novel treatments of this disease have led to the approval of new combinations. Improvements in knowledge of the biology of these tumors have been made, and it is now widely accepted that a proportion of patients have potentially targetable altered genes. One such gene is BRCA, which confers sensibility to PARP inhibitors. Olaparib, an oral PARP inhibitor, initially demonstrated activity in Phase II clinical trials including germline BRCA-mutated patients. This was confirmed in a Phase III clinical trial in pancreatic cancer patients with a germline BRCA mutation. After the results of this study, new scenarios have been evoked. We review the development of olaparib in pancreatic cancer.

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PARP Inhibitor Olaparib Use in a BRCA1-Positive Patient With Metastatic Triple-Negative Breast Cancer, Without the Initial Use of Platinum-Based Chemotherapy, Showing Significant Rapid Near Resolution of Large Liver Metastasis While Patient Experienced Gout-Like Symptoms

Journal of Investigative Medicine High Impact Case Reports ◽

10.1177/2324709619864989 ◽

2019 ◽

Vol 7 ◽

pp. 232470961986498 ◽

Cited By ~ 1

Author(s):

Trevanne Matthews Hew ◽

Lara Zuberi

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Brca Mutation ◽

Parp Inhibitor ◽

Parp Inhibitors ◽

Management Options ◽

Federal Drug Administration ◽

Platinum Based Chemotherapy ◽

Metastatic Setting

Triple-negative breast cancer (TNBC) accounts for 20% of breast cancers diagnosed worldwide. This subtype of breast cancer tends to behave more aggressively, and unlike other breast cancer subtypes, there are no standard targeted treatments for most patients. However, up to 20% of patients with TNBC harbor a breast cancer gene (BRCA) mutation, particularly in BRCA1. For patients who carry this gene mutation, this opens the door for new management options by the use of newer agents such as polyadenosine diphosphate-ribose polymerase (PARP) inhibitors in the metastatic setting. Given that this is uncommon and that PARP inhibitors have only recently received Federal Drug Administration approval, the experience with these drugs is relatively new. In this article, we present a case of a patient treated in this setting with olaparib who developed an unanticipated side effect as a result of the high efficacy of the drug.

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Phase I study of olaparib (O), in combination with oral cyclophosphamide (C), in patients (pts) with metastatic triple negative breast cancer (TNBC) and recurrent high grade serous ovarian cancer (OVCA).

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.1104 ◽

2017 ◽

Vol 35 (15_suppl) ◽

pp. 1104-1104

Author(s):

Chee Khoon Lee ◽

Clare L. Scott ◽

Geoffrey John Lindeman ◽

Emma Gibbs ◽

Heath D. Badger ◽

...

Keyword(s):

Dna Damage ◽

Dose Level ◽

Phase Ii ◽

Synthetic Lethality ◽

Brca Mutation ◽

Performance Status ◽

Eligible Patient ◽

Parp Inhibitors ◽

Germline Brca Mutation ◽

Recommended Phase Ii Dose

1104 Background: Poly (ADP-ribose) polymerase (PARP) inhibitors can potentiate chemotherapy induced DNA damage, through synthetic lethality, leading to increased tumor death. We hypothesized that O+C would increase antitumor activity of O through increased DNA damage induced by C. This study ( ANZCTR N12613000924752) evaluated the safety and activity of O+C. Methods: Eligible patient (pts) had performance status 0-2, with ≤3 lines of therapy (including platinum for OVCA and anthracycline and taxane for BC). Pts received O+C with a dose escalations strategy using a 3+3 design with cohort expansions once maximal tolerated dose (MTD) was determined. Dose level 1 (DL1); O, 300 mg bid continuously, C, 50mg on days 1,3 and 5 weekly, 21 day cycle. Dose level 2 (DL2); O, 300 mg bid continuously, C, 50mg days 1-5 weekly 21 day cycle. Dose limiting toxicity was evaluated during 1st two cycles. Safety was assessed by CTCAEv4.0 and efficacy with RECISTv1.1 and GCIC criteria. Results: Of the 32 pts (median age 56, 9 had BC ( BRCA1 22%, BRCA2 44%) and 23 had HGSOC ( BRCA1 39%, BRCA2 26%). 4 pts were treated at DL1 and 28 pts at DL2. DL2 was the MTD. At the time of analysis, 16 of 29 pts had 8 cycles of O+C, with 14 of 16 pts continued with O beyond the 8th cycle. One pt stopped because of adverse events (AEs) and the remaining 12 stopped due to disease progression. The median treatment duration of O+C was 4.3 months (0.7-23.5). Common AEs were nausea (Grade (Gr) 1/2: 88%, Gr 3: 3%), fatigue (Gr 1/2: 81%), constipation (Gr 1/2: 38%, Gr 3: 3%), and vomiting (Gr 1/2: 38%, Gr 3: 3 %). There were no grade (Gr) 4 or 5 AE. 50% required blood transfusion for anemia. Unconfirmed disease control rate (DCR) was 73% (N = 30; CR = 1, PR = 9, SD = 12). DCR for BC and HGSOC were 56% and 81% respectively. In the BRCA cohort (N = 19), DCR was 79%. GCIG CA125 response rates were 70% and 92% for all HGSOC and BRCA cohort respectively. Conclusions: In HGSOC and BC pts, the recommended phase II dose (O 300 mg bid continuously, C 50mg on days 1-5 weekly) is tolerable and active, particularly in those with germline BRCA mutation, supporting our hypothesis. A randomised phase II study in BRCA mutant HGSOC is planned. Clinical trial information: ACTRN12613000924752.

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Somatic versus germline BRCA mutations screening in ovarian cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.e13100 ◽

2017 ◽

Vol 35 (15_suppl) ◽

pp. e13100-e13100

Author(s):

Hugo SM Nunes ◽

Patricia Machado ◽

Sofia Fragoso ◽

Sidonia Santos ◽

Fernanda Silva ◽

...

Keyword(s):

Ovarian Cancer ◽

Somatic Mutations ◽

Brca Mutation ◽

Point Mutations ◽

Parp Inhibitors ◽

Brca Mutations ◽

Alu Element ◽

Brca1 Carriers ◽

Large Rearrangements ◽

Clinic Medical

e13100 Background: ovarian cancer (OC) with germinal or somatic BRCA mutations responds better to platinum and to PARP-inhibitors. There is great enthusiasm about BRCA somatic screening. Our aim was to analyse the correlation between BRCA somatic and germline mutational profile. Methods: a cohort of 23 pts was obtained by cross-linking OC pts from the South Portuguese Cancer Registry, between 2009-2014 and BRCA mutation carriers identified in our Clinic. Medical records were reviewed: demographic and clinico-pathologic data obtained. Germinal screening: pts were pre-screened for the BRCA2 Portuguese founder mutation (PFM), analysed for BRCA point mutations (different screening methodologies were used in diagnostic timeline: initially CSGE, then CSCE and finally NGS) and for large rearrangements by MLPA. Somatic screening: DNA was extracted from 5 sections of 10µm of FFPE tissue and analysed for BRCA1/2 genes by NGS. Results: clinico-pathological features of the 23 pts revealed mainly high-grade serous histology (96%). Mean age at diagnosis was 54 years old (33-76); BRCA2 were older than BRCA1 carriers (62 vs 51). Most pts presented at advanced stage (70% stages III-IV; 30% stage I-II). Seventeen were BRCA1 carriers and 6 were BRCA2 (5 of those PFM, a large insertion of an Alu element). Somatic correlation: 8 pts (5 BRCA1, 3PFM) were already analysed and 100% correlation was observed for all point mutations. One additional BRCA2 somatic mutation was detected (with a variant allele frequency of 53% whereas 2 others were < 7%); interestingly exclusive somatic mutations were only observed in PFM carriers (known not to be NGS detectable). The remaining 15 pts are under analysis. Conclusions: it was expected that the PFM and other large rearrangements would not be detected with NGS. A specific somatic screening for the PFM may be possible but other rearrangements are found by MLPA in our population (10% of all BRCA mutations). Preliminary data adds to the evidence that NGS OC somatic screening will identify all germinal point mutations and an indeterminate number of additional pts with exclusive somatic mutations. An ideal correlation needs integration of differenttechniques that may increase complexity, time and cost.

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Beyond Breast and Ovarian Cancers: PARP Inhibitors for BRCA Mutation-Associated and BRCA-Like Solid Tumors

Frontiers in Oncology ◽

10.3389/fonc.2014.00042 ◽

2014 ◽

Vol 4 ◽

Cited By ~ 32

Author(s):

Ciara C. O’Sullivan ◽

Dominic H. Moon ◽

Elise C. Kohn ◽

Jung-Min Lee

Keyword(s):

Solid Tumors ◽

Brca Mutation ◽

Parp Inhibitors ◽

Ovarian Cancers

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PARP inhibitors in BRCA mutation-associated ovarian cancer

The Lancet Oncology ◽

10.1016/s1470-2045(14)71172-6 ◽

2015 ◽

Vol 16 (1) ◽

pp. 10-12 ◽

Cited By ~ 11

Author(s):

Andrew Clamp ◽

Gordon Jayson

Keyword(s):

Ovarian Cancer ◽

Brca Mutation ◽

Parp Inhibitors

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PARP Inhibitors in Ovarian Cancer: The Route to “Ithaca”

Diagnostics ◽

10.3390/diagnostics9020055 ◽

2019 ◽

Vol 9 (2) ◽

pp. 55 ◽

Cited By ~ 16

Author(s):

Boussios ◽

Karathanasi ◽

Cooke ◽

Neille ◽

Sadauskaite ◽

...

Keyword(s):

Ovarian Cancer ◽

Dna Repair ◽

Homologous Recombination ◽

Brca Mutation ◽

Parp Inhibitor ◽

Parp Inhibitors ◽

Parp Inhibition ◽

Current Evidence ◽

Repair Pathway ◽

Significant Efficacy

Poly (ADP-ribose) polymerase (PARP) inhibitors are a novel class of therapeutic agents that target tumors with deficiencies in the homologous recombination DNA repair pathway. Genomic instability characterizes high-grade serous ovarian cancer (HGSOC), with one half of all tumors displaying defects in the important DNA repair pathway of homologous recombination. Early studies have shown significant efficacy for PARP inhibitors in patients with germline breast related cancer antigens 1 and 2 (BRCA1/2) mutations. It has also become evident that BRCA wild-type patients with other defects in the homologous recombination repair pathway benefit from this treatment. Companion homologous recombination deficiency (HRD) scores are being developed to guide the selection of patients that are most likely to benefit from PARP inhibition. The choice of which PARP inhibitor is mainly based upon the number of prior therapies and the presence of a BRCA mutation or HRD. The identification of patients most likely to benefit from PARP inhibitor therapy in view of HRD and other biomarker assessments is still challenging. The aim of this review is to describe the current evidence for PARP inhibitors in ovarian cancer, their mechanism of action, and the outstanding issues, including the rate of long-term toxicities and the evolution of resistance.

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Germline BRCA1and BRCA2 mutations in patients with HER2-negative metastatic breast cancer (mBC) treated with first-line chemotherapy: Data from the German PRAEGNANT registry.

Journal of Clinical Oncology ◽

10.1200/jco.2019.37.15_suppl.1048 ◽

2019 ◽

Vol 37 (15_suppl) ◽

pp. 1048-1048

Author(s):

Peter A. Fasching ◽

Chunling Hu ◽

Steven Hart ◽

Andreas D. Hartkopf ◽

Florin A Taran ◽

...

Keyword(s):

Regression Models ◽

Cox Regression ◽

Brca Mutation ◽

Statistical Significance ◽

Brca2 Mutation ◽

Metastatic Breast ◽

Progression Free Survival ◽

Parp Inhibitors ◽

First Line ◽

Metastatic Setting

1048 Background: Germline BRCA1/2 ( gBRCA) mutations (mt) are some of the few actionable alterations in mBC patients. The PARP inhibitors olaparib/talazoparib are more effective than chemotherapy (ctx) in patients with a gBRCAmt and HER2 negative(-) mBC. In mBC patients the TNT-study suggested a better progression-free survival (PFS) for g BRCA-mt compared to patients with a gBRCA1/2 wildtype (wt) when treated with platinum and not with a taxane. Otherwise little is known about the prognostic effect of g BRCA1/2mt in mBC patients. Methods: PRAEGNANT (NCT02338167) is a prospective mBC registry with a focus on molecular biomarkers. Patients were eligible for this analysis if their mBC was HER2- and treated with ctx for the first time (referred to as first-line ctx). Hormone receptor (HR) positive patients had to have all hormone therapies exhausted. Mutation frequencies and their association with patient and tumor characteristics were analyzed. Multivariable Cox regression models were built with commonly established prognostic factors and g BRCA mutation status as predictors of PFS and overall survival (OS) from first-line ctx. Results: Out of 2932 PRAEGNANT patients, 576 were HER2- and received first-line ctx. Of those 529 patients with g BRCA genotype results and follow up information could be analyzed. 24 patients (4.5%) had a g BRCAmt (11 BRCA1, 13 BRCA2). Mutation rate in HR positive patients was 3.9% (17/432) and 7.2% (7/97) in HR negative patients. Most patients received ctx either as the first treatment in the metastatic setting or after one line of hormone therapy (n=382; 72.2%). Multivariable Cox regression models showed an adjusted hazard ratio for gBRCAmt vs. gBRCAwt patients of 0.70 (95% CI: 0.43-1.15) for PFS and of 0.41 (95% CI: 0.18-0.93) for OS. Most frequent ctx treatments were taxane (52%) or capecitabine based (21%). Additionally, the prevalence of somatic BRCA1/2 mutations in this population will be presented. Conclusions: In this HER2- mBC population under ctx g BRCA mutation rates were within the expected range of about 5%. Within the analyzed population patients with a g BRCA mutation seemed to have a better OS than patients without a mutation. PFS results pointed in the same direction without statistical significance. However, with only 24 mutations replication of these results in additional cohorts is warranted. Clinical trial information: NCT02338167.

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Olaparib as maintenance treatment for patients with platinum-sensitive relapsed ovarian cancer

Therapeutic Advances in Medical Oncology ◽

10.1177/1758835919849753 ◽

2019 ◽

Vol 11 ◽

pp. 175883591984975 ◽

Cited By ~ 15

Author(s):

Jonathan A. Ledermann ◽

Eric Pujade-Lauraine

Keyword(s):

Ovarian Cancer ◽

Brca Mutation ◽

Parp Inhibitors ◽

European Medicines Agency ◽

Clinical Safety ◽

Platinum Sensitive ◽

Repair Deficiency ◽

Recombination Repair ◽

Term Tolerability

Poly (ADP-ribose) polymerase (PARP) inhibitors were developed with the intention of treating patients with homologous recombination repair deficiency (HRD), specifically for patients with tumours that harbour a BRCA mutation (BRCAm). Evidence from clinical trials to date has demonstrated that patients with a BRCAm derive the greatest benefit from PARP inhibitors. However, clinical studies have also shown that PARP inhibitors provide benefit to women with ovarian cancer who do not have a BRCAm. The recent updated approvals of olaparib, niraparib and rucaparib by the US Food and Drug Administration and the European Medicines Agency for the treatment of all platinum-sensitive relapsed (PSR) ovarian-cancer populations, regardless of their BRCAm status, support this. Long-term tolerability and efficacy of olaparib have been demonstrated in patients both with and without a BRCAm, with 13% of patients receiving maintenance olaparib for at least 5 years in one study, which is unprecedented in the relapsed ovarian-cancer setting ( versus 1% on placebo). Further studies should be performed to elucidate which non-BRCAm patients are deriving benefit and what molecular processes are enabling this, so that patients continue to receive optimal treatment for their disease. Here, we review clinical and molecular markers of HRD, the long-term clinical safety and efficacy of PARP inhibitors in ovarian cancer, with a focus on olaparib and the current approved indications for PARP inhibitors, as well as guidance on treatment decisions for patients with PSR ovarian cancer.

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Expanding the Use of PARP Inhibitors as Monotherapy and in Combination in Triple-Negative Breast Cancer

Pharmaceuticals ◽

10.3390/ph14121270 ◽

2021 ◽

Vol 14 (12) ◽

pp. 1270

Author(s):

Mariya Yordanova ◽

Audrey Hubert ◽

Saima Hassan

Keyword(s):

Breast Cancer ◽

Homologous Recombination ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Brca Mutation ◽

Single Agent ◽

Parp Inhibitors ◽

Breast Cancer Patients ◽

Homologous Recombination Deficiency ◽

Dosing Strategies

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and is known to be associated with a poor prognosis and limited therapeutic options. Poly (ADP-ribose) polymerase inhibitors (PARPi) are targeted therapeutics that have demonstrated efficacy as monotherapy in metastatic BRCA-mutant (BRCAMUT) TNBC patients. Improved efficacy of PARPi has been demonstrated in BRCAMUT breast cancer patients who have either received fewer lines of chemotherapy or in chemotherapy-naïve patients in the metastatic, adjuvant, and neoadjuvant settings. Moreover, recent trials in smaller cohorts have identified anti-tumor activity of PARPi in TNBC patients, regardless of BRCA-mutation status. While there have been concerns regarding the efficacy and toxicity of the use of PARPi in combination with chemotherapy, these challenges can be mitigated with careful attention to PARPi dosing strategies. To better identify a patient subpopulation that will best respond to PARPi, several genomic biomarkers of homologous recombination deficiency have been tested. However, gene expression signatures associated with PARPi response can integrate different pathways in addition to homologous recombination deficiency and can be implemented in the clinic more readily. Taken together, PARPi have great potential for use in TNBC patients beyond BRCAMUT status, both as a single-agent and in combination.

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