Purpose Olaparib is an oral poly (ADP-ribose) polymerase inhibitor with activity in germline BRCA1 and BRCA2 (BRCA1/2) –associated breast and ovarian cancers. We evaluated the efficacy and safety of olaparib in a spectrum of BRCA1/2-associated cancers. Patients and Methods This multicenter phase II study enrolled individuals with a germline BRCA1/2 mutation and recurrent cancer. Eligibility included ovarian cancer resistant to prior platinum; breast cancer with ≥ three chemotherapy regimens for metastatic disease; pancreatic cancer with prior gemcitabine treatment; or prostate cancer with progression on hormonal and one systemic therapy. Olaparib was administered at 400 mg twice per day. The primary efficacy end point was tumor response rate. Results A total of 298 patients received treatment and were evaluable. The tumor response rate was 26.2% (78 of 298; 95% CI, 21.3 to 31.6) overall and 31.1% (60 of 193; 95% CI, 24.6 to 38.1), 12.9% (eight of 62; 95% CI, 5.7 to 23.9), 21.7% (five of 23; 95% CI, 7.5 to 43.7), and 50.0% (four of eight; 95% CI, 15.7 to 84.3) in ovarian, breast, pancreatic, and prostate cancers, respectively. Stable disease ≥ 8 weeks was observed in 42% of patients (95% CI, 36.0 to 47.4), including 40% (95% CI, 33.4 to 47.7), 47% (95% CI, 34.0 to 59.9), 35% (95% CI, 16.4 to 57.3), and 25% (95% CI, 3.2 to 65.1) of those with ovarian, breast, pancreatic, or prostate cancer, respectively. The most common adverse events (AEs) were fatigue, nausea, and vomiting. Grade ≥ 3 AEs were reported for 54% of patients; anemia was the most common (17%). Conclusion Responses to olaparib were observed across different tumor types associated with germline BRCA1/2 mutations. Olaparib warrants further investigation in confirmatory studies.

Background: In the phase III IMpassion130 trial, combining atezolizumab with first-line nanoparticle albumin-boundpaclitaxel for advanced triple-negative breast cancer (aTNBC) showed a statistically significant progression-free survival (PFS) benefit in the intention-to-treat (ITT) and programmed death-ligand 1 (PD-L1)-positive populations, and a clinically meaningful overall survival (OS) effect in PD-L1-positive aTNBC. The phase III KEYNOTE-355 trial adding pembrolizumab to chemotherapy for aTNBC showed similar PFS effects. IMpassion131 evaluated first-line atezolizumabepaclitaxel in aTNBC. Patients and methods: Eligible patients [no prior systemic therapy or 12 months since (neo)adjuvant chemotherapy] were randomised 2:1 to atezolizumab 840 mg or placebo (days 1, 15), both with paclitaxel 90 mg/m 2 (days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. Stratification factors were tumour PD-L1 status, prior taxane, liver metastases and geographical region. The primary endpoint was investigator-assessed PFS, tested hierarchically first in the PD-L1-positive [immune cell expression 1%, VENTANA PD-L1 (SP142) assay] population, and then in the ITT population. OS was a secondary endpoint. Results: Of 651 randomised patients, 45% had PD-L1-positive aTNBC. At the primary PFS analysis, adding atezolizumab to paclitaxel did not improve investigator-assessed PFS in the PD-L1-positive population [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.60-1.12; P ¼ 0.20; median PFS 6.0 months with atezolizumabepaclitaxel versus 5.7 months with placeboepaclitaxel]. In the PD-L1-positive population, atezolizumabepaclitaxel was associated with more favourable unconfirmed best overall response rate (63% versus 55% with placeboepaclitaxel) and median duration of response (7.2 versus 5.5 months, respectively). Final OS results showed no difference between arms (HR 1.11, 95% CI 0.76-1.64; median 22.1 months with atezolizumabepaclitaxel versus 28.3 months with placeboe paclitaxel in the PD-L1-positive population). Results in the ITT population were consistent with the PD-L1-positive population. The safety profile was consistent with known effects of each study drug. Conclusion: Combining atezolizumab with paclitaxel did not improve PFS or OS versus paclitaxel alone. ClinicalTrials.gov: NCT03125902.

Objective The efficacy and safety of olaparib, an oral poly(ADP-ribose) polymerase (PARP) inhibitor, was investigated in a subgroup of patients with germline BRCA1/2 mutated (gBRCA1/2m) advanced ovarian cancer who had received ≥3 prior lines of chemotherapy. Primary data from this Phase II study (Study 42, ClinicalTrials.gov NCT01078662) have been reported previously. Methods Eligible patients were treated with oral olaparib 400 mg bid capsule monotherapy until disease progression according to RECIST v1.1. Objective response rate (ORR) and duration of response (DoR) were assessed for patients with measurable disease at baseline. Safety and tolerability were assessed for all patients by adverse event (AE) incidence and changes in laboratory parameters. Platinum resistance status was obtained retrospectively, and responses to olaparib evaluated. Results In patients with gBRCA1/2m ovarian cancer, 154/193 (80%) had received ≥3 prior lines of chemotherapy, of whom 137/154 (89%) had measurable disease at baseline. ORR was 34% (46/137; 95% confidence interval [CI] 26–42) and median DoR was 7.9 (95% CI 5.6–9.6) months. ORR in platinum-resistant tumors was 30%. Median DoR for platinum-sensitive and platinum-resistant disease was similar: 8.2 months (95% CI 5.6–13.5) compared with 8.0 months (4.8–14.8), respectively. Six of the 193 (3%) patients had an AE with an outcome of death. None of these AEs at time of occurrence was considered causally related to olaparib. Conclusion Following ≥3 prior lines of chemotherapy, olaparib 400 mg bid (capsule form) monotherapy demonstrated notable antitumor activity in patients with gBRCA1/2m advanced ovarian cancer. No new safety signals were identified.