Genmab's Experimental Ovarian Cancer Drug Shows Sustained Response Rates in Phase 2 Trial

Genmab announced Phase 2 results for rinatabart sesutecan, an investigational cancer treatment that achieved a 45.9% response rate among 109 patients with platinum-resistant ovarian cancer. Responses persisted for a median of 12.1 months, with approximately half of responders still showing benefit after one year. The drug demonstrated effectiveness regardless of folate receptor expression levels, expanding its potential patient population.

Rinatabart sesutecan targets folate receptor alpha, a protein often found on cancer cells, and works by delivering a topoisomerase inhibitor directly to tumors. The drug showed clinical benefit in a challenging patient population—most had already undergone multiple previous treatment regimens and had been exposed to several standard-of-care options including bevacizumab, taxanes, and PARP inhibitors. A notable finding was the drug's activity across patients regardless of how much folate receptor they expressed, potentially broadening its applicability.

The median follow-up period exceeded one year, allowing researchers to assess durability. About half of patients who initially responded maintained that response after 12 months, suggesting sustained therapeutic benefit rather than temporary tumor shrinkage.