Olaparib Maintenance Beneficial for Ovarian Cancer With BRCA Mutation

According to findings from a clinical trial on the efficacy of maintenance olaparib therapy for patients with ovarian cancer and BRCA mutation, the treatment yielded extended rates of progression-free (PFS) and recurrence-free survival (RFS) when administered after first-line platinum-based chemotherapy.

“Newly diagnosed advanced patients with ovarian cancer are at high risk of relapse and 5-year survival is 30%-50%. Delay of recurrence, prolonged survival and, for some patients, increased chance of cure are goals of treatment in this setting,” wrote lead investigator Susana Banerjee, PhD, Royal Marsden Hospital NHS Foundation Trust and Institute of Cancer Research, London, United Kingdom, and colleagues.

“In SOLO1 patients with ovarian cancer and BRCA mutation who were in response after first-line platinum-based chemotherapy derived significant [PFS] benefit from maintenance olaparib vs placebo,” they continued.

A total of 391 patients patients with ovarian cancer and BRCA mutation responding after first-line platinum-based chemotherapy were included in the SOLO1 study, including 260 randomized to receive maintenance olaparib 300 mg tablets and 131 randomized to receive placebo for 24.6 and 13.9 months, respectively. Patients were followed-up with for 5 years, with data cut off in March 2020.

The primary end points were PFS and RFS, investigator-assessed in accordance with modified RECIST v1.1. RFS was defined post-hoc as the time from randomization to disease recurrence or death for patients in complete response (CR) at baseline.

After a median follow-up of 4.8 and 5.0 years for the olaparib and placebo arms, respectively, the median PFS was 56.0 versus 13.8 months, respectively. In addition, the RFS was 15.3 months for those given placebo but not reached in those given olaparib.

The risk for disease recurrence or death was reduced by 63% amongst patients in CR at baseline.

There were no new cases of myelodysplastic syndrome or acute myeloid leukemia reported, whereas the incidence of new primary malignancies was similar between both treatment arms (olaparib, 7 [3%] vs placebo, 5 [4%]).

“For patients with a BRCA mutation and newly diagnosed advanced ovarian cancer the benefit derived from 2 years of maintenance olaparib was sustained beyond the end of treatment and after 5 years almost half of patients were progression-free vs 20% with placebo,” wrote Dr Banerjee et al.

“5-year follow up is the longest for any PARP inhibitor in this setting and no new safety signals were observed,” they concluded.—Alexandra Graziano

Source: Banerjee S, Moore KN, Colombo N, et al. Maintenance olaparib for patients (pts) with newly diagnosed, advanced ovarian cancer (OC) and a BRCA mutation (BRCAm): 5-year (y) follow-up (f/u) from SOLO1. Presented at: the ESMO Virtual Congress 2020; September 19-21, 2020; virtual. Abstract 811MO.