-
Journal of Clinical Oncology : Official... Apr 2020A phase II study (ClinicalTrials.gov identifier: NCT00628251) showed activity of olaparib capsules versus pegylated liposomal doxorubicin in patients with germline... (Comparative Study)
Comparative Study Randomized Controlled Trial
Olaparib Versus Nonplatinum Chemotherapy in Patients With Platinum-Sensitive Relapsed Ovarian Cancer and a Germline BRCA1/2 Mutation (SOLO3): A Randomized Phase III Trial.
PURPOSE
A phase II study (ClinicalTrials.gov identifier: NCT00628251) showed activity of olaparib capsules versus pegylated liposomal doxorubicin in patients with germline BRCA-mutated platinum-resistant or partially platinum-sensitive relapsed ovarian cancer. We conducted a phase III trial (SOLO3) of olaparib tablets versus nonplatinum chemotherapy in patients with germline BRCA-mutated platinum-sensitive relapsed ovarian cancer who had received at least 2 prior lines of platinum-based chemotherapy.
PATIENTS AND METHODS
In this randomized, open-label trial, patients were randomly assigned 2:1 to olaparib 300 mg twice a day or physician's choice single-agent nonplatinum chemotherapy (pegylated liposomal doxorubicin, paclitaxel, gemcitabine, or topotecan). The primary end point was objective response rate (ORR) in the measurable disease analysis set assessed by blinded independent central review (BICR). The key secondary end point was progression-free survival (PFS) assessed by BICR in the intent-to-treat population.
RESULTS
Of 266 randomly assigned patients, 178 were assigned to olaparib and 88 to chemotherapy. In patients with measurable disease (olaparib, n = 151; chemotherapy, n = 72), the BICR-assessed ORR was significantly higher with olaparib than with chemotherapy (72.2% 51.4%; odds ratio [OR], 2.53 [95% CI, 1.40 to 4.58]; = .002). In the subgroup who had received 2 prior lines of treatment, the ORR was 84.6% with olaparib and 61.5% with chemotherapy (OR, 3.44 [95% CI, 1.42 to 8.54]). BICR-assessed PFS also significantly favored olaparib versus chemotherapy (hazard ratio, 0.62 [95% CI, 0.43 to 0.91]; = .013; median, 13.4 9.2 months). Adverse events were consistent with the established safety profiles of olaparib and chemotherapy.
CONCLUSION
Olaparib resulted in statistically significant and clinically relevant improvements in ORR and PFS compared with nonplatinum chemotherapy in patients with germline BRCA-mutated platinum-sensitive relapsed ovarian cancer who had received at least 2 prior lines of platinum-based chemotherapy.
Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Female; Genes, BRCA1; Genes, BRCA2; Germ-Line Mutation; Humans; Middle Aged; Neoplasm Recurrence, Local; Ovarian Neoplasms; Phthalazines; Piperazines; Platinum Compounds
PubMed: 32073956
DOI: 10.1200/JCO.19.02745 -
The New England Journal of Medicine Apr 2012Olaparib (AZD2281) is an oral poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitor that has shown antitumor activity in patients with high-grade serous ovarian... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Olaparib (AZD2281) is an oral poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitor that has shown antitumor activity in patients with high-grade serous ovarian cancer with or without BRCA1 or BRCA2 germline mutations.
METHODS
We conducted a randomized, double-blind, placebo-controlled, phase 2 study to evaluate maintenance treatment with olaparib in patients with platinum-sensitive, relapsed, high-grade serous ovarian cancer who had received two or more platinum-based regimens and had had a partial or complete response to their most recent platinum-based regimen. Patients were randomly assigned to receive olaparib, at a dose of 400 mg twice daily, or placebo. The primary end point was progression-free survival according to the Response Evaluation Criteria in Solid Tumors guidelines.
RESULTS
Of 265 patients who underwent randomization, 136 were assigned to the olaparib group and 129 to the placebo group. Progression-free survival was significantly longer with olaparib than with placebo (median, 8.4 months vs. 4.8 months from randomization on completion of chemotherapy; hazard ratio for progression or death, 0.35; 95% confidence interval [CI], 0.25 to 0.49; P<0.001). Subgroup analyses of progression-free survival showed that, regardless of subgroup, patients in the olaparib group had a lower risk of progression. Adverse events more commonly reported in the olaparib group than in the placebo group (by more than 10% of patients) were nausea (68% vs. 35%), fatigue (49% vs. 38%), vomiting (32% vs. 14%), and anemia (17% vs. 5%); the majority of adverse events were grade 1 or 2. An interim analysis of overall survival (38% maturity, meaning that 38% of the patients had died) showed no significant difference between groups (hazard ratio with olaparib, 0.94; 95% CI, 0.63 to 1.39; P=0.75).
CONCLUSIONS
Olaparib as maintenance treatment significantly improved progression-free survival among patients with platinum-sensitive, relapsed, high-grade serous ovarian cancer. Interim analysis showed no overall survival benefit. The toxicity profile of olaparib in this population was consistent with that in previous studies. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT00753545.).
Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Disease-Free Survival; Double-Blind Method; Female; Genes, BRCA1; Genes, BRCA2; Germ-Line Mutation; Humans; Kaplan-Meier Estimate; Maintenance Chemotherapy; Middle Aged; Neoplasm Grading; Neoplasm Recurrence, Local; Ovarian Neoplasms; Phthalazines; Piperazines; Young Adult
PubMed: 22452356
DOI: 10.1056/NEJMoa1105535 -
Annals of Oncology : Official Journal... Feb 2023In the phase III PAOLA-1 study, the addition of maintenance olaparib to bevacizumab in patients with newly diagnosed high-grade ovarian cancer (HGOC) resulted in...
Association of location of BRCA1 and BRCA2 mutations with benefit from olaparib and bevacizumab maintenance in high-grade ovarian cancer: phase III PAOLA-1/ENGOT-ov25 trial subgroup exploratory analysis.
BACKGROUND
In the phase III PAOLA-1 study, the addition of maintenance olaparib to bevacizumab in patients with newly diagnosed high-grade ovarian cancer (HGOC) resulted in prolonged progression-free survival (PFS), particularly for homologous recombination deficiency-positive tumors, including those with a BRCA mutation (BRCAm). The magnitude of benefit from olaparib and bevacizumab according to the location of mutation in BRCA1/BRCA2 remains to be explored.
PATIENTS AND METHODS
Patients with advanced-stage HGOC responding after platinum-based chemotherapy + bevacizumab received maintenance therapy bevacizumab (15 mg/kg q3w for 15 months) + either olaparib (300 mg b.i.d. for 24 months) or placebo. PFS was analyzed in the subgroup of patients with BRCA1m/BRCA2m according to mutation location in the functional domains of BRCA1 [Really Interesting Gene (RING), DNA-binding domain (DBD), or C-terminal domain of BRCA1 (BRCT)] and BRCA2 [RAD51-binding domain (RAD51-BD); DBD].
RESULTS
From 806 randomized patients, 159 harbored BRCA1m (19.7%) and 74 BRCA2m (9.2%). BRCA1m in RING, DBD, and BRCT domains was detected in 18, 40, and 33 patients, and BRCA2m in RAD51-BD and DBD in 36 and 13 patients, respectively. After a median follow-up of 25.5 months, benefit from maintenance olaparib + bevacizumab was observed irrespective of location of BRCAm. The benefit was particularly high for those with BRCA1m located in the DBD, with 24-month PFS estimated to be 89% and 15% [olaparib + bevacizumab versus placebo + bevacizumab hazard ratio = 0.08 (95% confidence interval 0.02-0.28); interaction P = 0.03]. In BRCA2m patients, 24-month PFS rates for those with mutations located in the DBD were 90% and 100% (olaparib + bevacizumab versus placebo + bevacizumab), respectively.
CONCLUSIONS
Advanced-stage BRCA-mutated HGOC patients reported PFS benefit from maintenance olaparib and bevacizumab regardless of mutation location. The benefit is particularly high for patients with mutations located in the DBD of BRCA1. Mutations located in the DBD of BRCA2 are also associated with excellent outcome.
Topics: Humans; Female; Bevacizumab; Antineoplastic Agents; Ovarian Neoplasms; BRCA1 Protein; Phthalazines; Mutation; Maintenance Chemotherapy; BRCA2 Protein
PubMed: 36564284
DOI: 10.1016/j.annonc.2022.11.003 -
The New England Journal of Medicine Jul 2009The inhibition of poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) is a potential synthetic lethal therapeutic strategy for the treatment of cancers with...
BACKGROUND
The inhibition of poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) is a potential synthetic lethal therapeutic strategy for the treatment of cancers with specific DNA-repair defects, including those arising in carriers of a BRCA1 or BRCA2 mutation. We conducted a clinical evaluation in humans of olaparib (AZD2281), a novel, potent, orally active PARP inhibitor.
METHODS
This was a phase 1 trial that included the analysis of pharmacokinetic and pharmacodynamic characteristics of olaparib. Selection was aimed at having a study population enriched in carriers of a BRCA1 or BRCA2 mutation.
RESULTS
We enrolled and treated 60 patients; 22 were carriers of a BRCA1 or BRCA2 mutation and 1 had a strong family history of BRCA-associated cancer but declined to undergo mutational testing. The olaparib dose and schedule were increased from 10 mg daily for 2 of every 3 weeks to 600 mg twice daily continuously. Reversible dose-limiting toxicity was seen in one of eight patients receiving 400 mg twice daily (grade 3 mood alteration and fatigue) and two of five patients receiving 600 mg twice daily (grade 4 thrombocytopenia and grade 3 somnolence). This led us to enroll another cohort, consisting only of carriers of a BRCA1 or BRCA2 mutation, to receive olaparib at a dose of 200 mg twice daily. Other adverse effects included mild gastrointestinal symptoms. There was no obvious increase in adverse effects seen in the mutation carriers. Pharmacokinetic data indicated rapid absorption and elimination; pharmacodynamic studies confirmed PARP inhibition in surrogate samples (of peripheral-blood mononuclear cells and plucked eyebrow-hair follicles) and tumor tissue. Objective antitumor activity was reported only in mutation carriers, all of whom had ovarian, breast, or prostate cancer and had received multiple treatment regimens.
CONCLUSIONS
Olaparib has few of the adverse effects of conventional chemotherapy, inhibits PARP, and has antitumor activity in cancer associated with the BRCA1 or BRCA2 mutation. (ClinicalTrials.gov number, NCT00516373.)
Topics: Adult; Aged; Aged, 80 and over; Dose-Response Relationship, Drug; Drug Design; Female; Genes, BRCA1; Genes, BRCA2; Germ-Line Mutation; Heterozygote; Humans; Male; Middle Aged; Neoplasms; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; Young Adult
PubMed: 19553641
DOI: 10.1056/NEJMoa0900212 -
Annals of Oncology : Official Journal... Feb 2021The antitumor efficacy of PARP inhibitors (PARPi) for breast cancer patients harboring germline BRCA1/2 (gBRCA1/2) mutations is well established. While PARPi monotherapy...
BACKGROUND
The antitumor efficacy of PARP inhibitors (PARPi) for breast cancer patients harboring germline BRCA1/2 (gBRCA1/2) mutations is well established. While PARPi monotherapy was ineffective in patients with metastatic triple negative breast cancer (TNBC) wild type for BRCA1/2, we hypothesized that PARPi may be effective in primary TNBCs without previous chemotherapy exposure.
PATIENTS AND METHODS
In the phase II PETREMAC trial, patients with primary TNBC >2 cm received olaparib for up to 10 weeks before chemotherapy. Tumor biopsies collected before and after olaparib underwent targeted DNA sequencing (360 genes) and BRCA1 methylation analyses. In addition, BRCAness (multiplex ligation-dependent probe amplification), PAM50 gene expression, RAD51 foci, tumor-infiltrating lymphocytes (TILs) and PD-L1 analyses were performed on pretreatment samples.
RESULTS
The median pretreatment tumor diameter was 60 mm (range 25-112 mm). Eighteen out of 32 patients obtained an objective response (OR) to olaparib (56.3%). Somatic or germline mutations affecting homologous recombination (HR) were observed in 10/18 responders [OR 55.6%, 95% confidence interval (CI) 33.7-75.4] contrasting 1/14 non-responders (OR 7.1%; CI 1.3-31.5, P = 0.008). Among tumors without HR mutations, 6/8 responders versus 3/13 non-responders revealed BRCA1 hypermethylation (P = 0.03). Thus, 16/18 responders (88.9%, CI 67.2-96.9), in contrast to 4/14 non-responders (28.6%, CI 11.7-54.7, P = 0.0008), carried HR mutations and/or BRCA1 methylation. Excluding one gPALB2 and four gBRCA1/2 mutation carriers, 12/14 responders (85.7%, CI 60.1-96.0) versus 3/13 non-responders (23.1%, CI 8.2-50.3, P = 0.002) carried somatic HR mutations and/or BRCA1 methylation. In contrast to BRCAness signature or basal-like subtype, low RAD51 scores, high TIL or high PD-L1 expression all correlated to olaparib response.
CONCLUSION
Olaparib yielded a high clinical response rate in treatment-naïve TNBCs revealing HR deficiency, beyond germline HR mutations.
TRIAL REGISTRATION
ClinicalTrials.gov identifier: NCT02624973.
Topics: BRCA1 Protein; Humans; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; Triple Negative Breast Neoplasms
PubMed: 33242536
DOI: 10.1016/j.annonc.2020.11.009 -
European Journal of Cancer (Oxford,... May 2023In the Phase III OlympiAD study, olaparib significantly prolonged progression-free survival versus chemotherapy treatment of physician's choice (TPC) in patients with... (Randomized Controlled Trial)
Randomized Controlled Trial
OlympiAD extended follow-up for overall survival and safety: Olaparib versus chemotherapy treatment of physician's choice in patients with a germline BRCA mutation and HER2-negative metastatic breast cancer.
BACKGROUND
In the Phase III OlympiAD study, olaparib significantly prolonged progression-free survival versus chemotherapy treatment of physician's choice (TPC) in patients with germline BRCA-mutated (gBRCAm), human epidermal growth factor receptor 2-negative metastatic breast cancer (mBC). In the final pre-specified analysis (64% maturity), median overall survival (OS) was 19.3 months for olaparib and 17.1 months for TPC (P = 0.513). Post-hoc extended follow-up, 25.7 months longer than previously reported for OS, is reported.
PATIENTS AND METHODS
Patients with gBRCAm, human epidermal growth factor receptor 2-negative mBC, who had received ≤2 lines of chemotherapy for metastatic disease, were randomised 2:1 to olaparib (300 mg bid) or TPC. During extended follow-up, OS was analysed every 6 months using the stratified log-rank test (overall population) and Cox proportional hazards model (pre-specified subgroups).
RESULTS
In the overall population (302 patients; 76.8% maturity), median OS was 19.3 months for olaparib and 17.1 months for TPC (hazard ratio 0.89, 95% confidence interval 0.67-1.18); median follow-up was 18.9 and 15.5 months, respectively. Three-year survival was 27.9% for olaparib versus 21.2% for TPC. With olaparib, 8.8% of patients received study treatment for ≥3 years versus none with TPC. In first-line mBC, median OS was longer for olaparib than TPC (22.6 versus 14.7 months; hazard ratio 0.55, 95% confidence interval 0.33-0.95) and 3-year survival was 40.8% for olaparib versus 12.8% for TPC. No new serious adverse events related to olaparib were observed.
CONCLUSIONS
OS was consistent with previous analyses from OlympiAD. These findings support the possibility of meaningful long-term survival benefit with olaparib, particularly in first-line mBC.
Topics: Female; Humans; Breast Neoplasms; Follow-Up Studies; Germ-Line Mutation; Phthalazines; Physicians; Genes, BRCA1; Genes, BRCA2
PubMed: 36893711
DOI: 10.1016/j.ejca.2023.01.031 -
Annals of Oncology : Official Journal... Oct 2022In the SOLO2 trial (ENGOT Ov-21; NCT01874353), maintenance olaparib in patients with platinum-sensitive relapsed ovarian cancer (PSROC) and BRCA mutation significantly... (Randomized Controlled Trial)
Randomized Controlled Trial
Efficacy of subsequent chemotherapy for patients with BRCA1/2-mutated recurrent epithelial ovarian cancer progressing on olaparib versus placebo maintenance: post-hoc analyses of the SOLO2/ENGOT Ov-21 trial.
BACKGROUND
In the SOLO2 trial (ENGOT Ov-21; NCT01874353), maintenance olaparib in patients with platinum-sensitive relapsed ovarian cancer (PSROC) and BRCA mutation significantly improved progression-free survival (PFS) and prolonged overall survival (OS). Following disease progression on olaparib, efficacy of subsequent chemotherapy remains unknown.
PATIENTS AND METHODS
We conducted a post-hoc hypothesis-generating analysis of SOLO2 data to determine the efficacy of different chemotherapy regimens following RECIST disease progression in patients who received olaparib or placebo. We evaluated time to second progression (TTSP) calculated from the date of RECIST progression to the next progression/death.
RESULTS
The study population comprised 147 patients who received chemotherapy as their first subsequent treatment after RECIST progression. Of these, 69 (47%) and 78 (53%) were originally randomized to placebo and olaparib arms, respectively. In the placebo-treated cohort, 27/69 and 42/69 received non-platinum and platinum-based chemotherapy, respectively, compared with 24/78 and 54/78, respectively, in the olaparib-treated cohort. Among patients treated with chemotherapy (N = 147), TTSP was significantly longer in the placebo than in the olaparib arm: 12.1 versus 6.9 months [hazard ratio (HR) 2.17, 95% confidence interval (CI) 1.47-3.19]. Similar result was obtained on multivariable analysis adjusting for prognostic factors at RECIST progression (HR 2.13, 95% CI 1.41-3.22). Among patients treated with platinum-based chemotherapy (n = 96), TTSP was significantly longer in the placebo arm: 14.3 versus 7.0 months (HR 2.89, 95% CI 1.73-4.82). Conversely, among patients treated with non-platinum-based chemotherapy (n = 51), the TTSP was comparable in the placebo and olaparib arms: 8.3 versus 6.0 months (HR 1.58, 95% CI 0.86-2.90).
CONCLUSIONS
Following progression from maintenance olaparib in the recurrent setting, the efficacy of platinum-based subsequent chemotherapy seems to be reduced in BRCA1/2-mutated patients with PSROC compared to patients not previously receiving poly (ADP-ribose) polymerase inhibitors (PARPi). The optimal strategy for patients who relapse after PARPi is an area of ongoing research.
Topics: Adenosine Diphosphate; Antineoplastic Agents; BRCA1 Protein; BRCA2 Protein; Carcinoma, Ovarian Epithelial; Disease Progression; Female; Humans; Maintenance Chemotherapy; Neoplasm Recurrence, Local; Ovarian Neoplasms; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; Ribose
PubMed: 35772665
DOI: 10.1016/j.annonc.2022.06.011 -
Journal of Clinical Oncology : Official... Dec 2022The phase III POLO study demonstrated significant progression-free survival (PFS) benefit for active olaparib maintenance therapy versus placebo for patients with... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
The phase III POLO study demonstrated significant progression-free survival (PFS) benefit for active olaparib maintenance therapy versus placebo for patients with metastatic pancreatic adenocarcinoma and a germline BRCA mutation. Here, we report the final analysis of overall survival (OS) and other secondary end points.
PATIENTS AND METHODS
Patients with a deleterious or suspected deleterious germline BRCA mutation whose disease had not progressed after ≥ 16 weeks of first-line platinum-based chemotherapy were randomly assigned 3:2 to active maintenance olaparib (300 mg twice daily) or placebo. The primary end point was PFS; secondary end points included OS, time to second disease progression or death, time to first and second subsequent cancer therapies or death, time to discontinuation of study treatment or death, and safety and tolerability.
RESULTS
In total, 154 patients were randomly assigned (olaparib, n = 92; placebo, n = 62). No statistically significant OS benefit was observed (median 19.0 19.2 months; hazard ratio [HR], 0.83; 95% CI, 0.56 to 1.22; = .3487). Kaplan-Meier OS curves separated at approximately 24 months, and the estimated 3-year survival after random assignment was 33.9% versus 17.8%, respectively. Median time to first subsequent cancer therapy or death (HR, 0.44; 95% CI, 0.30 to 0.66; < .0001), time to second subsequent cancer therapy or death (HR, 0.61; 95% CI, 0.42 to 0.89; = .0111), and time to discontinuation of study treatment or death (HR, 0.43; 95% CI, 0.29 to 0.63; < .0001) significantly favored olaparib. The HR for second disease progression or death favored olaparib without reaching statistical significance (HR, 0.66; 95% CI, 0.43 to 1.02; = .0613). Olaparib was well tolerated with no new safety signals.
CONCLUSION
Although no statistically significant OS benefit was observed, the HR numerically favored olaparib, which also conferred clinically meaningful benefits including increased time off chemotherapy and long-term survival in a subset of patients.
Topics: Humans; Female; Adenocarcinoma; Pancreatic Neoplasms; Neoplasm Recurrence, Local; Phthalazines; Germ Cells; Disease Progression; Ovarian Neoplasms
PubMed: 35834777
DOI: 10.1200/JCO.21.01604 -
Clinical Cancer Research : An Official... Jan 2023The phase III PROfound study (NCT02987543) evaluated olaparib versus abiraterone or enzalutamide (control) in metastatic castration-resistant prostate cancer (mCRPC)...
PURPOSE
The phase III PROfound study (NCT02987543) evaluated olaparib versus abiraterone or enzalutamide (control) in metastatic castration-resistant prostate cancer (mCRPC) with tumor homologous recombination repair (HRR) gene alterations. We present exploratory analyses on the use of circulating tumor DNA (ctDNA) testing as an additional method to identify patients with mCRPC with HRR gene alterations who may be eligible for olaparib treatment.
PATIENTS AND METHODS
Plasma samples collected during screening in PROfound were retrospectively sequenced using the FoundationOne®Liquid CDx test for BRCA1, BRCA2 (BRCA), and ATM alterations in ctDNA. Only patients from Cohort A (BRCA/ATM alteration positive by tissue testing) were evaluated. We compared clinical outcomes, including radiographic progression-free survival (rPFS) between the ctDNA subgroup and Cohort A.
RESULTS
Of the 181 (73.9%) Cohort A patients who gave consent for plasma sample ctDNA testing, 139 (76.8%) yielded a result and BRCA/ATM alterations were identified in 111 (79.9%). Of these, 73 patients received olaparib and 38 received control. Patients' baseline demographics and characteristics, and the prevalence of HRR alterations were comparable with the Cohort A intention-to-treat (ITT) population. rPFS was longer in the olaparib group versus control [median 7.4 vs. 3.5 months; hazard ratio (HR), 0.33; 95% confidence interval (CI), 0.21-0.53; nominal P < 0.0001], which is consistent with Cohort A ITT population (HR, 0.34; 95% CI, 0.25-0.47).
CONCLUSIONS
When tumor tissue testing is not feasible or has failed, ctDNA testing may be a suitable alternative to identify patients with mCRPC carrying BRCA/ATM alterations who may benefit from olaparib treatment.
Topics: Humans; Male; Ataxia Telangiectasia Mutated Proteins; BRCA1 Protein; BRCA2 Protein; Circulating Tumor DNA; Genes, BRCA2; Prostatic Neoplasms, Castration-Resistant; Retrospective Studies
PubMed: 36318705
DOI: 10.1158/1078-0432.CCR-21-3577 -
JAMA Oncology May 2021The subtype of pancreatic ductal adenocarcinoma cancer (PDAC) with DNA damage repair (DDR) deficiency from BRCA1/2 variants has a favorable prognosis and is sensitive to...
Olaparib Monotherapy for Previously Treated Pancreatic Cancer With DNA Damage Repair Genetic Alterations Other Than Germline BRCA Variants: Findings From 2 Phase 2 Nonrandomized Clinical Trials.
IMPORTANCE
The subtype of pancreatic ductal adenocarcinoma cancer (PDAC) with DNA damage repair (DDR) deficiency from BRCA1/2 variants has a favorable prognosis and is sensitive to platinum analogues and poly-(adenosine diphosphate-ripose) polymerase (PARP) inhibition with olaparib. Approximately 10% to 20% of patients with PDAC have DDR genetic alterations other than germline BRCA variants. This population has been termed as having BRCAness. An opportunity exists to define the clinical phenotype, molecular underpinnings, and effectiveness of PARP inhibitors for this population.
OBJECTIVE
To examine the therapeutic effectiveness of the PARP inhibitor olaparib for patients with pancreatic cancer with BRCAness.
DESIGN, SETTING, AND PARTICIPANTS
Two parallel phase 2 nonrandomized clinical trials were conducted from November 11, 2016, to October 2, 2018, among 46 patients in Israel and Texas to determine the effectiveness of olaparib as monotherapy in advanced, previously treated PDAC with BRCAness. Inclusion criteria were treatment with 1 or more prior systemic therapies for advanced PDAC, Eastern Cooperative Oncology Group performance status of 0 to 1, and lack of the germline BRCA1/2 variant. BRCAness in these studies was defined as previously known DDR genetic alterations (DDR-GAs), personal or family history of BRCA-associated cancers (without DDR-GAs), or ATM protein loss as determined by immunohistochemistry.
MAIN OUTCOMES AND MEASURES
The primary study end point was the objective response rate, and the secondary end points were progression-free survival and overall survival (OS).
RESULTS
Forty-eight patients were enrolled, and 46 (26 women [57%]; mean [SD] age, 65.5 [11.1] years) were evaluable. The median treatment duration with olaparib was 3.0 months (interquartile range, 1.8-6.4 months). A total of 24 patients had the DDR phenotype (DDR-GAs), 17 had a family history of BRCA-associated cancers without DDR-GAs, and 5 had ATM loss as determined by immunohistochemistry. The DDR-GAs included ATM (n = 14), PALB2 (n = 2), ARID1A (n = 3), BRCA somatic (n = 1), PTEN (n = 1), RAD51 (n = 1), CCNE (n = 1), and FANCB (n = 2). Common toxic effects were grade 1 to 2 anemia, fatigue, anorexia, and nausea. One patient had a confirmed partial response (2%), 33 patients experienced stable disease (72%), of whom 11 (24%) experienced disease stability longer than 4 months and 12 patients had progressive disease (26%). The response duration for the patient with confirmed partial response was 3.9 months. Median progression-free survival was 3.7 months (95% CI, 2.9-5.7) and was significantly higher for patients with DDR-GAs (5.7 months; 95% CI, 3.6-8.8 months; P = .008) and platinum-sensitive PDAC (4.1 months; 95% CI, 3.6-7.8 months; P = .01). The estimated median OS was 9.9 months (95% CI, 7.6-16.1 months) in the study and 13.6 months (95% CI, 9.69 to not reached) in the prespecified DDR-GA cohort.
CONCLUSIONS AND RELEVANCE
The definition of the BRCAness phenotype in PDAC may be limited to patients harboring DDR-GAs. In these 2 phase 2 nonrandomized clinical trials, olaparib was well tolerated and showed limited antitumor activity in patients with advanced, platinum-sensitive PDAC with DDR-GAs. These conclusions suggest a potential therapeutic opportunity for a subset of patients with PDAC.
Topics: Aged; BRCA1 Protein; DNA Damage; Female; Germ Cells; Humans; Male; Middle Aged; Pancreatic Neoplasms; Phthalazines; Piperazines
PubMed: 33662100
DOI: 10.1001/jamaoncol.2021.0006