In an analysis from the SOLO-1 trial reported in the Journal of Clinical Oncology, DiSilvestro et al found that olaparib vs placebo maintenance therapy after first-line platinum-based therapy in patients with advanced BRCA-mutated ovarian cancer significantly improved progression-free survival in predefined patient subgroups.
In the entire trial population, olaparib (300 mg twice daily) significantly improved progression-free survival vs placebo (median = not reached vs 13.8 months, hazard ratio [HR] = 0.30, P < .0001). The trial supported the December 2018 U.S. Food and Drug Administration approval of olaparib for the first-line maintenance treatment of advanced BRCA-mutated ovarian cancer.
“Patients with newly diagnosed advanced ovarian cancer achieve substantial benefit from maintenance olaparib treatment regardless of baseline surgery outcome, response to chemotherapy, or BRCA mutation type.”— Paul DiSilvestro, MD, and colleagues
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Study Details
The total intent-to-treat population consisted of 391 patients, with 260 receiving olaparib and 131 receiving placebo. Subgroups evaluated consisted of those according to clinical response after platinum-based chemotherapy (complete or partial response), surgery type (upfront or interval surgery), disease status after surgery (residual or no gross residual disease), and BRCA mutation status (BRCA1 or BRCA2).
Key Findings
Progression-free survival was significantly improved with olaparib vs placebo both among patients with a clinical complete response after chemotherapy (median = not reached vs 15.3 months, HR = 0.34, 95% confidence interval [CI] = 0.24–0.47) and among those with a partial response (median = 30.9 vs 8.4 months, HR = 0.31, 95% CI = 0.18–0.52).
Significant improvement was observed both among patients undergoing upfront surgery (median = not reached vs 15.3 months, HR = 0.31, 95% CI = 0.21–0.46) and among those undergoing interval surgery (median = 33.6 vs 9.8 months, HR = 0.37, 95% CI = 0.24–0.58).
Significant improvement was observed both among those with residual disease after surgery (median = 29.4 vs 11.3 months, HR = 0.44, 95% CI = 0.25–0.77) and among those with no gross residual disease after surgery (median = not reached vs 15.3 months, HR = 0.33, 95% CI = 0.23–0.46). Significant improvement was also observed among those with no gross residual disease after upfront surgery (median = not reached vs 22.0 months, HR = 0.33, 95% CI = 0.20–0.51) and among those with residual disease after upfront surgery (median = not reached vs 11.3 months, HR = 0.29, 95% CI = 0.15–0.58).
Significant improvement was observed both among patients with a BRCA1 mutation (median = 41.4 vs 13.8 months, HR = 0.41, 95% CI = 0.30-0.56) and among those with a BRCA2 mutation (median = not reached vs 13.8 months, HR = 0.20, 95% CI = 0.10–0.37).
The investigators concluded, “Patients with newly diagnosed advanced ovarian cancer achieve substantial benefit from maintenance olaparib treatment regardless of baseline surgery outcome, response to chemotherapy, or BRCA mutation type.”
Paul DiSilvestro, MD, of Women & Infants Hospital, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by AstraZeneca as part of an alliance between AstraZeneca and Merck Sharp & Dohme, a subsidiary of Merck & Co. For full disclosures of the study authors, visit ascopubs.org.
