Olaparib Treatment for Platinum-Sensitive Relapsed Ovarian Cancer: SOLO3 Trial
Posted: Monday, July 13, 2020
The PARP inhibitor olaparib seems to improve objective response rate and progression-free survival compared with single-agent nonplatinum chemotherapy in patients with platinum-sensitive relapsed ovarian cancer with germline BRCA mutations who previously received two or more lines of chemotherapy. The results are from the randomized phase III SOLO3 trial. Richard T. Penson, MD, of Harvard Medical School and Massachusetts General Hospital, and colleagues published the findings in the Journal of Clinical Oncology.
“SOLO3 met its primary endpoint, showing a statistically significant and clinically relevant improvement in objective response rate in favor of olaparib,” the authors wrote.
The open-label randomized trial enrolled patients with platinum-sensitive relapsed ovarian cancer who had germline BRCA1/2 mutations and who previously received two or more lines of platinum-based chemotherapy. Of 266 patients, 178 (151 with measurable disease) received olaparib, and 88 (72 with measurable disease) received chemotherapy. Patients received either 300 mg of olaparib twice per day or investigator’s choice of paclitaxel, gemcitabine, topotecan, or pegylated liposomal doxorubicin. Objective response rate and progression-free survival were assessed by blinded independent central review.
The primary endpoint, objective response rate in the measurable disease population, was significantly higher with olaparib (72%) than with chemotherapy (51%), with an odds ratio of 2.53. The secondary endpoint, progression-free survival in the intent-to-treat population, was also significantly better with olaparib (median, 13.4 months) than with chemotherapy (median, 9.2 months), with a hazard ratio of 0.62.
“Adverse events were consistent with the established safety profiles,” the authors wrote, but patients receiving chemotherapy were more than twice as likely to stop treatment because of an adverse event than those receiving olaparib. The open-label design, though a limitation, was necessary because the treatments have different delivery routes and schedules.
Disclosure: The study authors’ disclosure information may be found at ascopubs.org.