Commenting on the SOLO2 trial for The ASCO Post was Don S. Dizon, MD, FACP, FASCO, Director of Women’s Cancers at Lifespan Cancer Institute and Professor of Medicine at Brown University, Providence, Rhode Island.
Don S. Dizon, MD, FACP, FASCO
“It’s great to get an overall survival advantage from a PARP inhibitor study. Coming into these results, we had consistently shown that PARP inhibitors improve progression-free survival in advanced ovarian cancer, but we’ve been waiting for the overall survival data,” he said. That said, while support for using PARP inhibitors is greatly boosted by the findings of SOLO2, questions remain, Dr. Dizon added.
SOLO1 studied olaparib maintenance in newly diagnosed patients and showed that 60% of the maintenance arm was progression-free at 3 years; survival data are still pending. The SOLO2 population had received at least two prior lines of therapy but were olaparib-naive. All patients had BRCA mutations and had responded to platinum-based chemotherapy.
“The issue is that PARP inhibitors have shown activity in pretty much all the ovarian cancer treatment settings, particularly for BRCA-mutated disease. Importantly, they are used in the front-line setting as well. A lot of oncologists have started to use PARP inhibitors as part of the standard of care in the first line,” he said. “So what is not yet answered is this: If you use olaparib in the front-line setting and the patient has disease progression, and you treat with platinum and achieve remission, can you use olaparib again as maintenance, based on SOLO2? Can I tell this patient she can expect a survival benefit? Based on the data, I don’t think I can.”
Dr. Dizon added that patients with homologous recombination repair deficiency (HRD)—including some patients with BRCA wild-type disease—also may respond to PARP inhibition, though not as robustly. He tests for this in his patients and offers those with HRD-positive disease PARP inhibitors.
DISCLOSURE: Dr. Dizon serves on data safety monitoring boards for Clovis Oncology, AstraZeneca, and Regeneron and has institutional support for clinical trials funded by Bristol-Myers Squibb, Tesaro, Kazia Therapeutics, and Lilly.
In the final, preplanned, overall survival analysis in the randomized phase III SOLO2/ENGOT-ov211 trial, maintenance treatment with the PARP inhibitor olaparib extended overall survival by an unprecedented 12.9 months, compared with placebo. This marks the first time that overall survival has been...