Maintenance Olaparib for Ovarian Cancer: Subgroup Analysis From SOLO1 Trial
Posted: Tuesday, September 22, 2020
In the SOLO1 trial, maintenance therapy with olaparib was shown to increase progression-free survival in BRCA1/2-positive patients with advanced ovarian cancer compared with placebo. A group of researchers, led by Kathleen N. Moore, MD, of the University of Oklahoma’s Stephenson Cancer Center, Oklahoma City, reevaluated SOLO1 to examine progression-free survival in different patient subgroups, including by complete or partial response to treatment, mutation type, surgery type, and disease status after surgery. The results were published in the Journal of Clinical Oncology.
In this randomized, phase III, multicenter, double-blind study, researchers focused on the following types of stage III or IV cancer: serous or endometrioid ovarian, primary peritoneal, or fallopian tube. Patients in partial or complete remission after receiving cytoreductive surgery and first-line platinum-based chemotherapy were eligible for the study. A total of 391 patients with mutations in BRCA1 (282), BRCA2 (106), or both (3) were enrolled in the study. Patients received first-line platinum-based chemotherapy and were then randomly enrolled in a 2:1 olaparib-to-placebo ratio.
Progression-free survival was improved in each patient group receiving olaparib when compared with the placebo. Patients in the olaparib group with BRCA1 mutations had a 59% reduction in the risk of disease progression or death, and patients with BRCA2 mutations had an 80% reduction when compared with their placebo counterparts. Similarly, those who received upfront surgery had a 69% reduction in the risk of disease progression or death, and those who received interval surgery had a 63% reduction. Patients either with (56%) or without (67%) residual disease after surgery also benefited from olaparib, as did those in complete remission (66%) or partial remission (69%) at baseline.
The study authors 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.”
Disclosure: For full disclosures of the study authors, visit ascopubs.org.