Dr Mathews on Maintenance Olaparib in Ovarian Cancer

Cara A. Mathews, MD, associate professor, obstetrics and gynecology, Brown University; gynecologic oncologist, Women & Infants Hospital, discusses 7-year overall survival (OS) data from the phase 3 SOLO-1 trial (NCT01844986) in patients with ovarian cancer.

The SOLO-1 trial investigated the efficacy of maintenance olaparib (Lynparza) vs placebo in patients with newly diagnosed advanced high-grade serous or endometrioid ovarian cancer, fallopian tube cancer, and/or primary peritoneal cancer who had BRCA1 and/or BRCA2–mutated disease and who had achieved a clinical response to platinum-based therapy. Primary results from this trial showed that at a median follow-up of 41 months, the estimated progression-free survival rate was 60% in the olaparib arm vs 27% in the placebo arm.

The interim OS analysis, performed when the OS data were 21% mature, showed that the estimated 3-year OS rate was 84% in the olaparib arm vs 80% in the placebo arm. Additionally, the median time to first subsequent treatment or death was 51.8 months and 15.1 months in the olaparib and placebo arms, respectively, with an estimated 74% of patients in the olaparib arm and 56% of patients in the placebo arm alive and not requiring a second subsequent treatment at 3 years.

Dr Mathews on 7-Year OS Data From SOLO-1

The 7-year OS analysis of SOLO-1 showed a clinically meaningful benefit with olaparib, with an OS rate of 67.0% in the olaparib arm vs 46.5% in the placebo arm, Mathews says. However, these OS data did not reach statistical significance because the trial’s statistical design for OS is powered for the final analysis, Mathews notes.

Dr Mathews on Time to Subsequent Therapy in SOLO-1

These 7-year OS findings show a meaningful clinical benefit with olaparib in patients with ovarian cancer harboring BRCA mutations, Mathews says. Another outcome measured in this 7-year analysis of SOLO-1 was the time until patients’ first subsequent therapy. At 7 years, 45.3% of the patients who received olaparib had never received subsequent therapy and were still alive vs 20.6% of patients in the placebo arm. This nearly 25% difference in favor of olaparib between the percentage of patients who required subsequent therapy in each arm highlights the benefit of olaparib maintenance therapy in this population, Mathews concludes.

Editor’s Note: Dr Mathews reports grants to her institution from Syros, Deciphera, Astellas Pharma, GlaxoSmithKline/Tesaro, Seattle Genetics, EMD Serono, Merck, Regeneron, Moderna, AstraZeneca, and Laekna.