Maintenance therapy with olaparib was found to result in a clinically meaningful, but not statistically significant, improvement in overall survival compared with placebo among women with platinum-sensitive, BRCA 1/2-mutated, relapsed ovarian cancer, according to the results of a study published in The Lancet Oncology.
Previously published results from the SOLO2/ENGOT-Ov21 trial (ClinicalTrials.gov Identifier: NCT01874353) demonstrated significantly longer progression-free survival with olaparib maintenance therapy compared with placebo. The present analysis includes overall survival during a median follow-up of 65.7 months for the olaparib group.
The double-blind, placebo-controlled, phase 3 trial randomly assigned 295 patients with BRCA1/2-mutated, relapsed ovarian cancer to receive olaparib (66%) or placebo (34%). All patients demonstrated partial or complete response at enrollment after their most recent platinum regimen. Patients had received at least 2 prior platinum regimens. The primary endpoint was progression-free survival, which was already reported; overall survival was a secondary endpoint.
Treatment with olaparib was associated with prolonged overall survival with a median of 51.7 months compared with 38.8 months for placebo; however, this did not meet the predefined threshold for significance (hazard ratio, 0.74; 95% CI, 0.54-1.00; P =.54).
Treatment-emergent adverse events (TEAEs) led to treatment discontinuation in 17% of patients in the olaparib group and 3% of patients in the placebo group. Serious TEAEs occurred in 26% and 8% of patients in the olaparib and placebo groups, respectively. Anemia, intestinal obstruction, myelodysplastic syndrome, constipation, and small intestinal obstruction were the most common TEAEs reported in both groups.
The authors concluded that “Olaparib provided a median overall survival benefit of 12.9 months compared with placebo in patients with platinum-sensitive, relapsed ovarian cancer and a BRCA1/2 mutation.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Reference
Poveda A, Floquet A, Ledermann JA, et al. Olaparib tablets as maintenance therapy in patients with platinum-sensitive relapsed ovarian cancer and a BRCA1/2 mutation (SOLO2/ENGOT-Ov21): a final analysis of a double-blind, randomised, placebo-controlled, phase 3 trial. Lancet Oncol. Published online March 18, 2021. doi:org/10.1016/S1470-2045(21)00073-5