Maintenance therapy with olaparib extended overall survival by nearly 13 months (12.9) compared with placebo in women with platinum-sensitive relapsed ovarian cancer with BRCA 1 or 2 mutations, in a randomised phase III trial.

At 5 years follow up, 42.1% of women on the poly ADP-ribose polymerase (PARP) inhibitor olaparib were alive vs. 33.2% on placebo.

The findings come from the randomised phase III SOLO-2 trial and represent the first overall survival data for a PARP inhibitor in this group of patients.

The results will be presented during the virtual scientific program of the 2020 American Society of Clinical Oncology (ASCO) Annual Meeting.

“A median overall survival improvement of nearly 13 months is impressive in ovarian cancer and brings a substantial benefit to our patients,” said lead author Andres Poveda, MD, of Initia Oncology, Hospital Quironsalud, in Valencia, Spain. “With the addition of overall survival data, this study helps usher in a new era of personalized medicine for women with this difficult-to-treat cancer.”

In this double-blind, multi-centre trial, 196 patients with relapsed BRCA-related ovarian cancer responding to platinum-based chemotherapy were randomised to receive olaparib tablets, while 99 received placebo.

The patients had also previously received at least two lines of chemotherapy and had cancer that was responding to recent platinum-based chemotherapy.

After median follow-up of 65 months, 28.3% of patients who received olaparib were alive and had not received subsequent treatment, compared with 12.8% of patients who received a placebo.

Patients receiving olaparib in the time between disease response and progression had a 26% reduced risk of death.

In addition, 38.4% of patients in the placebo group crossed over to treatment with olaparib.

The unique mechanism of PARP inhibitors highlights the role of targeted therapies for specific gene mutations.

BRCA mutations are well-established targets for treatment with PARP inhibitors. 

“This study confirms that the PARP inhibitor olaparib should be the standard maintenance therapy for patients with BRCA-related relapsed ovarian cancer responding to platinum-based chemotherapy – a significant advance for women with a cancer that has a historically poor prognosis,” said ASCO Chief Medical Officer and Executive Vice President Richard L. Schilsky, MD, FASP, FSCT, FASCO.

Source: ASCO