Olaparib Yields Better Response, Survival Than Chemo in Relapsed Ovarian Cancer

Among pretreated patients with germline BRCA-mutated platinum-sensitive relapsed ovarian cancer, olaparib led to significant improvements in objective response rate (ORR) and progression-free survival (PFS) than nonplatinum chemotherapy (J Clin Oncol. 2020 Feb 19. Epub ahead of print).

“A phase II study showed activity of olaparib capsules versus pegylated liposomal doxorubicin in patients with germline BRCA-mutated platinum-resistant or partially platinum-sensitive relapsed ovarian cancer,” said Richard T. Penson, MD, MRCP, Massachusetts General Hospital, Boston, and colleagues, who compared olaparib with nonplatinum chemotherapy in a phase 3 study of pretreated patients with germline BRCA-mutated platinum-sensitive relapsed ovarian cancer.

Overall, 266 patients were included in the open-label SOLO3 trial and randomized in a 2:1 ratio to receive olaparib 300 mg twice daily (n = 178) or physician's choice of single-agent nonplatinum chemotherapy (n = 88).

The main end point of SOLO3 was ORR in the measurable disease analysis set, and a significant secondary end point was PFS evaluated in the intent-to-treat population.

Among patients with measurable disease, including 151 in the olaparib arm and 72 in the chemotherapy arm, the ORR was significantly higher with olaparib versus chemotherapy (72.2% vs 51.4%, respectively; odds ratio [OR], 2.53; 95% CI, 1.40-4.58; P = .002).

Furthermore, patients in the olaparib and chemotherapy arms who had 2 prior lines of chemotherapy had ORRs of 84.6% and 61.5%, respectively (OR, 3.44; 95% CI, 1.42-8.54). The PFS rated were also found to significantly favor olaparib over chemotherapy (median, 13.4 vs 9.2 months, respectively; hazard ratio, 0.62; 95% CI, 0.43-0.91; P = .013).

“Adverse events were consistent with the established safety profiles of olaparib and chemotherapy,” Dr Penson and co-investigators reported.

“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,” they concluded.—Hina Porcelli