Immunotherapy's Evolving Role in Ovarian Cancer: Nicoletta Colombo, MD, PhD

Platinum-resistant, recurrent ovarian cancer remains a difficult clinical situation, but weekly paclitaxel with bevacizumab and pembrolizumab has emerged as an effective regimen. Data presented at the European Society for Medical Oncology Annual Congress 2025 showed significant improvements in overall survival and one of the longest observed progression-free survival outcomes in patients with this type of cancer.1

Nicoletta Colombo, MD, PhD, associate professor of obstetrics and gynecology at the University of Milan-Bicocca, director of the Ovarian Cancer Centre, and chair of the Program of Gynecology at the European Institute of Oncology, spoke to The American Journal of Managed Care® about the scientific rationale behind the regimen and the emergence of antibody-drug conjugates (ADCs) in ovarian cancer.

In the second interim analysis of the KEYNOTE-B96 trial (NCT05116189) of pembrolizumab (Keytruda; Merck) plus chemotherapy in platinum-resistant recurrent ovarian cancer, patients with a combined positive score of 1 or higher in the pembrolizumab arm had a median PFS of 8.3 months in the pembrolizumab arm vs 7.2 months in the placebo arm. The 12-month PFS rates were 35.9% and 23.9%, respectively. At 18 months, the PFS rates were 18.7% and 10.5%, respectively. In the pembrolizumab arm, median OS was 18.2 months vs 14 months in the placebo group; the 12-month OS rates were 69.1% and 59.3%; and the 18-month OS rates were 51.5% and 38.9%.

At the second interim analysis, the intention-to-treat population had a median PFS of 8.3 months vs 6.4 months in the placebo group. The 12-month PFS rates were 33.7% and 22.5% in the pembrolizumab and placebo arms, respectively, and the 18-month PFS rates were 17.3% and 9.0%.

“We are in an era right now with so many new drugs coming, and I'm referring mainly to the ADCs,” Colombo said. “Of course, there are so many new ADCs with very promising results, and I think for our patients, it is much better to have more options than no options. But at the end of the day, we will have to understand how to sequence all these new modalities.”

Reference

Colombo N, Zsiros E, Sebastianelli A, et al. Pembrolizumab vs placebo plus weekly paclitaxel ± bevacizumab in platinum-resistant recurrent ovarian cancer: results from the randomized double-blind phase III ENGOT-ov65/KEYNOTE-B96 study. Presented at: 50th European Society for Medical Oncology Congress; October 17-21, 2025; Berlin, Germany. Abstract LBA3.