Olaparib Monotherapy for Ovarian Cancer Evaluated in SOLO3 Trial
Posted: Tuesday, July 30, 2019
The results of the randomized phase III SOLO3 trial indicated better efficacy with olaparib monotherapy versus pegylated liposomal doxorubicin (PLD) and other types of nonplatinum chemotherapy in patients with germline BRCA-mutated platinum-sensitive relapsed ovarian cancer, in both overall response rate and progression-free survival. Presented at the 2019 American Society for Clinical Oncology (ASCO) Annual Meeting in Chicago (Abstract 5506), the SOLO3 outcomes also showed no new safety signals.
Richard T. Penson, MD, of Massachusetts General Hospital in Boston, and colleagues noted that their confirmatory work was driven in part in response to data from a randomized, 97-patient phase II trial; although this study favored olaparib in this setting, higher efficacy was shown with PLD than previously reported. The SOLO3 trial focused on 266 patients, randomly assigned to the PARP inhibitor olaparib (n = 178) and the chemotherapy treatment of physician’s choice (including PLD, n = 47; paclitaxel, n = 20; gemcitabine, n = 13; and topotecan, n = 8).
The overall response rate by blinded independent central review, the primary endpoint, was 72% with olaparib versus 51% with chemotherapy (P = .002). The hazard ratio for progression-free survival, a secondary endpoint, was 0.62 by blinded independent central review (P = .013), with a median of 13.4 months for olaparib versus 9.2 months for chemotherapy. By investigator assessment, the progression-free survival hazard ratio was 0.49 (P < .001), with medians of 13.2 versus 8.5 months for the respective treatments.
Regarding safety, another secondary endpoint, adverse events led to treatment discontinuation for 7% of patients in the olaparib arm versus 20% of patients in the chemotherapy arm, said Dr. Penson and his team. Serious adverse events occurred in 24% versus 18% in the treatment arms, respectively.
Disclosure: The study authors’ disclosure information may be found at coi.asco.org.