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.

Should platinum-based chemotherapy be preferred for germline BReast CAncer genes (BRCA) 1 and 2-mutated pancreatic ductal adenocarcinoma (PDAC) patients? A systematic review and meta-analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide. Recent studies have shown that 4-20% of patients with PDAC have a germline BReast CAncer (gBRCA) genes 1 and 2 mutation (m). Because homologous recombination is impaired in patients with gBRCAm, some reports suggested that these tumors may be more sensitive to platinum compounds. Therefore, this systematic review and meta-analysis focused on benefit of patients with gBRCAm receiving a platinum-based chemotherapy (PtCh) compared with those treated with a non-platinum-based chemotherapy (NPtCh).

MATERIAL AND METHODS

The following electronic databases were searched from inception to May 12, 2018: PubMed (MEDLINE), EMBASE, and Cochrane Library. Abstracts from conferences were also reviewed for inclusion. Cohort, case-control and randomized studies of patients with PDAC and gBRCAm were eligible for inclusion if they provided data to compare patients receiving PtCh vs NPtCh. The primary endpoint was overall survival (OS) in the PtCh group vs the NPtCh group in patients with clinical stage III (locally advanced) or IV (metastatic) (CS III-IV) PDAC.

RESULTS

Of 112 studies identified, 6 were included (total of 108 patients); of these, 4 provided sufficient data for meta-analysis. Half of the patients were males, with a mean age ranging from 58 to 63 years. The OS in the 85 patients with CS III-IV PDAC was higher in the PtCh group (23.7 vs 12.2 months; mean difference of 10.21 months, 95% confidence interval [CI] 5.05-15.37; P < 0.001; very low quality of evidence). PtCh was associated with a lower mortality (62.3 vs 87.5%; relative risk of 0.80, 95%CI 0.66-0.97; P = 0.021; very low quality of evidence).

CONCLUSION

Our study confirmed the hypothesis that patients with CS III-IV gBRCAm preferably benefit from a PtCh compared with NPtCh. However the very low quality of evidence should induce to be careful about the risk of potential biases. The generated hypothesis should be prospectively investigated in homogenous clinical settings.

Clinical Outcomes, Treatment Patterns, and Health Resource Utilization Among Metastatic Breast Cancer Patients with Germline BRCA1/2 Mutation: A Real-World Retrospective Study

INTRODUCTION

With evolving treatment guidelines for germline BRCA1/2 mutation (gBRCAm) in breast cancer, we present the latest gBRCA testing rates among metastatic breast cancer (mBC) patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) or triple-negative breast cancer (TNBC). Among these patients with gBRCAm, we analyzed clinical outcomes, treatment patterns, and health resource utilization (HRU).

METHODS

The Flatiron Health electronic health record database was used to assess gBRCA testing rates in a real-world retrospective analysis of US patients at least 18 years old with HR+/HER2- or TNBC, and with mBC diagnosed from January 2011 to February 2018. Outcomes were compared between gBRCAm patients with HR+/HER2- vs TNBC, adjusting for imbalances utilizing inverse probability treatment weighting; effects of HR+/HER2- vs TNBC on overall survival (OS) were assessed, antineoplastic treatments summarized, and HRU analyzed using t tests.

RESULTS

The study included 12,021 mBC patients (HR+/HER2-, 10,291; TNBC, 1730). Results for gBRCA testing were available for 2005 (16.7%) patients (HR+/HER2-, 1587; TNBC, 418). A total of 229 (1.9%) patients (HR+/HER2-, 165; TNBC, 64) had gBRCAm. Significantly worse OS in gBRCAm mBC was observed in TNBC vs HR+/HER2- [hazard ratio (95% confidence interval), 0.45 (0.27-0.74); p = 0.002]. Estimated median and 4-year OS rates for gBRCAm mBC patients with either HR+/HER2- or TNBC were 38.0 months, 23.4 months and 35.6%, 21.2% respectively. The most common first-line treatment post diagnosis for gBRCAm HR+/HER2- was letrozole (8%) vs capecitabine (14%) for gBRCAm TNBC. The number of HRU treatment visits per patient per year was significantly (p < 0.05) higher among gBRCAm mBC patients with TNBC vs HR+/HER2-.

CONCLUSION

Among HER2- mBC patients, gBRCA testing rates are low. Among gBRCAm HER2- mBC patients, the poor OS and HRU burden observed, especially in patients with TNBC, demonstrate an unmet need for more efficacious, targeted, and less HRU-intensive treatment options.

FUNDING

Pfizer.

BRCA1/2 mutations associated with progression-free survival in ovarian cancer patients in the AGO-OVAR 16 study

OBJECTIVE

AGO-OVAR 16 demonstrated that pazopanib maintenance therapy significantly increased progression-free survival (PFS) in patients with ovarian cancer whose disease had not progressed after first-line therapy. In a sub-study, we evaluated the effect of clinically important germline BRCA1 and BRCA2 mutations on PFS.

METHODS

Of 940 AGO-OVAR 16 participants, 664 had BRCA1/2 exon sequencing data (pazopanib, n=335; placebo, n=329). A Cox model was used to test the association between genetic variants and PFS.

RESULTS

Ninety-seven of 664 patients (15%) carried clinically important BRCA1/2 mutations (BRCA1/2 carriers: pazopanib 14%, placebo 16%). Median PFS was longer in BRCA1/2 mutation carriers than in BRCA1/2 non-carriers in the placebo arm (30.3 vs 14.1 months, hazard ratio, 0.48; 95% confidence interval [CI]: 0.29-0.78; P=0.0031); a similar non-significant trend was noted with pazopanib (30.2 vs 17.7 months, hazard ratio, 0.64; 95% CI: 0.40-1.03; P=0.069). Among BRCA1/2 non-carriers, PFS was longer for pazopanib-treated patients than placebo-treated patients (17.7 vs 14.1 months, hazard ratio, 0.77; 95% CI: 0.62-0.97; P=0.024). Among BRCA1/2 carriers, there was no significant PFS difference between treatments, although numbers were small (pazopanib, 46; placebo, 51), resulting in a wide CI (hazard ratio, 1.36; 95% CI: 0.66-2.82).

CONCLUSIONS

Patients with clinically important BRCA1/2 mutations had better prognosis. BRCA1/2 mutation status might be added as strata in future trials in primary ovarian cancer.