William Bradley, MD, Medical College of Wisconsin, Milwaukee, discusses 5-year follow-up results from the SOLO-1 trial, which aimed to assess the long-term efficacy and tolerability of maintenance olaparib for newly diagnosed advanced ovarian cancer.

These results were presented at the 2021 Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancer.

Transcript

Hello, I'm William Bradley. I'm an associate professor of gynecologic oncology in the Department of Obstetrics and Gynecology at Froedtert and the Medical College of Wisconsin.

I recently had the honor of presenting the data for the 5-year follow-up of the SOLO-1 trial. This is a trial addressing the utilization of olaparib, a PARP inhibitor, in women with epithelial ovarian cancer and a somatic or germline mutation in BRCA1 or 2 genes.

The 5-year follow-up was done after a 2-year exposure to either the treatment arm which was olaparib or the control arm which was a placebo. Patients, as we remember on this study, were randomized 2:1 to receive the treatment arm and over 300 patients were treated on studying.

At 2 years, the follow-up demonstrated a significant improvement in progression-free survival for the patients who received olaparib. What's interesting about this 5-year study is that it demonstrates this progression-free survival benefit was maintained after the conclusion of exposure to olaparib.

The vast majority of patients in this trial stopped taking olaparib at 2 years, and the median exposure was just over 24 months. Despite that, the patients who received olaparib for maintenance for that 2-year period enjoyed a significantly improved progression-free survival at a 5-year interval.

Furthermore, these patients were divided into what were considered to be higher-risk and lower-risk groups. Higher-risk groups were patients who had residual disease at the conclusion of their debulking surgery, who underwent neoadjuvant chemotherapy, or who were staged IV at the initial diagnosis.

Even those higher-risk patients received an equivalent benefit in progression-free survival compared to the placebo arm. The durability of this benefit is very impressive, as is the safety signal which was followed for the full 5 years.

Safety signal looked at some of the severe toxicities of exposure to PARP inhibitor including AML and myelodysplastic syndrome. This did not demonstrate that there was an increased rate of these findings. In fact after the 5-year follow-up, there were no new signal events concerning for toxicity.

Bradley W, et al. Maintenance olaparib for patients with newly diagnosed, advanced ovarian cancer and a BRCA mutation: 5-year follow-up from SOLO1. Presented at: the virtual 2021 SGO Annual Meeting on Women’s Cancer; March 19-25, 2021. Abstract 10520.

Dr Bradley reports no relevant financial relationships.