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In the primary analysis of the phase III OlympiAD trial, olaparib significantly prolonged progression‐free survival (PFS) vs chemotherapy treatment of physician's choice (TPC) in patients with germline BRCA‐mutated (gBRCAm), HER2‐negative metastatic breast cancer (mBC). We report subgroup analyses for the final analysis at a median OS follow‐up of 18.9 months (olaparib) and 15.5 months (TPC). Patients (N = 302) with gBRCAm, HER2‐negative mBC and ≤2 previous lines of chemotherapy for mBC were randomized 2:1 to open‐label olaparib (300 mg twice daily) or TPC. All subgroup analyses were prespecified except site of metastases. Investigator‐assessed median PFS was 8.0 months (95% confidence interval [CI] 5.8‐8.4; 176/205 events) for olaparib and 3.8 months (95% CI 2.8‐4.2; 83/97 events) for TPC (hazard ratio 0.51, 95% CI 0.39‐0.66). In subgroup analyses, median PFS hazard ratios (95% CI) favored olaparib: hormone receptor status (triple‐negative: 0.47, 0.32‐0.69; hormone receptor‐positive: 0.52, 0.36‐0.75); gBRCAm (BRCA1: 0.49, 0.35‐0.71; BRCA2: 0.49, 0.33‐0.74); site of metastases (visceral/CNS: 0.53, 0.40‐0.71; non‐visceral: 0.45, 0.23‐0.98); prior chemotherapy for mBC (yes: 0.51, 0.38‐0.70; no: 0.49, 0.30‐0.82); prior platinum‐based chemotherapy for BC (yes: 0.49, 0.30‐0.83; no: 0.50, 0.37‐0.69); progressive disease at randomization (yes: 0.48, 0.35‐0.65; no: 0.61, 0.36‐1.07). Investigator‐assessed objective response rates were higher across all subgroups with olaparib (35‐68%) vs TPC (5‐40%). Global health status/health‐related quality of life increased in all subgroups with olaparib vs decreased/no change with TPC. These data confirm the consistency of olaparib benefit across patient subgroups in OlympiAD. [ABSTRACT FROM AUTHOR]

Background: Maintenance treatment with the oral poly(adenosine diphosphate ribose) polymerase (PARP) inhibitor olaparib (Lynparza) in Study 19 (study number, D0810C00019; ClinicalTrials.gov identifier, NCT00753545) significantly improved progression-free survival in comparison with a placebo for patients with platinum-sensitive, relapsed serous ovarian cancer with a BRCA1/2 mutation (BRCAm), but an interim analysis revealed no statistically significant overall survival (OS) benefit. However, 23% of the patients receiving the placebo switched to a PARP inhibitor after progression. To investigate whether this had a confounding effect on OS, this article reports an exploratory post hoc analysis that excluded all patients from sites where 1 or more placebo patients received postprogression PARP inhibitor treatment.Methods: In Study 19, 136 of the 265 patients receiving olaparib or a placebo had a BRCAm. Sixteen patients treated at 11 of the 82 investigational sites received a PARP inhibitor after progression; these sites were excluded from this analysis, and 97 BRCAm patients at 50 sites were included. OS was assessed with a Cox proportional hazards model analogous to the primary study analysis. A supporting rank-preserving structural failure time (RPSFT) model analysis was undertaken for all 136 BRCAm patients.Results: The OS hazard ratio (HR) was 0.52 (95% confidence interval [CI], 0.28-0.97) for the 97 BRCAm patients, whereas for the interim OS analysis with all 136 BRCAm patients, it was 0.73 (95% CI, 0.45-1.17). The supportive RPSFT analysis HR was approximately 0.66.Conclusions: The numerical improvement in the OS HR suggests that in Study 19, postprogression PARP inhibitor treatment had a confounding influence on the interim OS analysis for BRCAm patients. There is a degree of uncertainty due to the small sample size and the lack of data maturity. Cancer 2016;122:1844-52. © 2016 American Cancer Society. [ABSTRACT FROM AUTHOR]

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 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). 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. 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. • Median overall survival (OS) was 19.3 and 17.1 months for olaparib versus chemotherapy treatment of physician's choice (TPC), respectively. • Overall, 8.8% of patients received at least 3 years of study treatment in the olaparib arm versus no patients in the TPC arm. • In first-line, median OS was numerically longer for olaparib versus TPC (22.6 versus 14.7 months, respectively). • In first-line, the 3-year OS rate was 40.8% for olaparib versus 12.8% for TPC. • These data confirm previous findings and suggest a possible OS benefit for olaparib in the first-line metastatic breast cancer setting. [ABSTRACT FROM AUTHOR]

Purpose The metabolism of olaparib, a potent inhibitor of poly(ADP-ribose) polymerase (PARP) with demonstrated efficacy in patients with BRCA -mutated ovarian cancer, is mediated by cytochrome P450 (CYP) enzymes (predominantly CYP3A4/5). We assessed the potential of a CYP3A4 inhibitor (itraconazole) and inducer (rifampin) to alter the pharmacokinetic (PK) profile of olaparib following single oral tablet doses. Methods Two Phase I, open-label, non-randomized trials were conducted in patients with advanced solid tumors. In Study 7, patients received olaparib alone and co-administered with itraconazole; in Study 8, a separate group of patients received olaparib alone and co-administered with rifampin. No interaction between itraconazole and olaparib was concluded if two-sided 90% CIs for the treatment ratios of AUC and/or AUC 0–t and C max fell within the bioequivalence range of 0.80–1.25. An interaction between rifampin and olaparib was concluded if the lower limit of the 90% CI for the treatment ratios was <0.5 (ie, >50% decrease in olaparib AUC or C max in the presence of rifampin compared with olaparib alone). Findings In Study 7 (N = 59; 17 male, 42 female), 56 and 53 patients were evaluable for PK analysis following treatment with olaparib alone and olaparib plus itraconazole, respectively; in Study 8 (N = 22; 4 male, 18 female), all patients were evaluable. Co-administration of olaparib with itraconazole resulted in a statistically significant increase in the relative bioavailability of olaparib: C max treatment ratio, 1.42 (90% CI, 1.33–1.52); mean AUC treatment ratio, 2.70 (90% CI, 2.44–2.97). Mean CL/F and V z /F were reduced (8.16 vs 3.05 L/h and 192 vs 75.1 L), although mean t ½ was unchanged (15.0 vs 15.6 hours). Co-administration of olaparib with rifampin resulted in a statistically significant decrease in the relative bioavailability of olaparib: C max treatment ratio, 0.29 (90% CI, 0.24–0.33); mean AUC treatment ratio, 0.13 (90% CI, 0.11–0.16). CL/F and V z /F were increased when olaparib and rifampin were co-administered (6.36 vs 48.3 L/h and 112 vs 1076 L); however, mean t ½ was unchanged (13.0 vs 15.8 hours). Safety data for olaparib following tablet dosing were consistent with the known safety profile. Implications Exposure to olaparib was significantly increased when co-administered with the potent CYP3A4 inhibitor itraconazole, and significantly decreased when co-administered with the potent CYP3A4 inducer rifampin, compared with olaparib alone. Potent CYP3A4 enzyme inhibitors and inducers should be avoided during olaparib treatment. ClinicalTrials.gov identifiers: NCT01900028 (Study 7) and NCT01929603 (Study 8). [ABSTRACT FROM AUTHOR]