Genmab reports 45.9% response rate for Rina-S in ovarian cancer study

Genmab said its experimental drug rinatabart sesutecan, or Rina-S, produced a confirmed objective response rate of 45.9% in 109 treated patients with platinum-resistant ovarian cancer, with five complete responses and a median duration of response of 12.1 months. The results were presented on October 3, 2026, at the International Gynecologic Cancer Society Congress in Montreal.

The company also said median progression-free survival in the Part C cohort of the Phase 1/2 RAINFOL-01 trial was 9.5 months. It added that antitumor activity was observed regardless of folate receptor alpha, or FRα, expression levels, including in low expressors and non-expressors, and regardless of prior treatment with mirvetuximab.

For people following drug development in ovarian cancer, the data matter because the study was run in patients with platinum-resistant disease, where Genmab said all patients had already received bevacizumab and taxane therapy, and many had received several earlier lines of treatment. More than half of the patients, 53%, had received three or four prior lines, while 49.5% had received a prior PARP inhibitor and 33% had received prior mirvetuximab soravtansine.

Genmab said the most common treatment-emergent adverse events included fatigue, nausea, vomiting, constipation, decreased appetite and abdominal pain. The most frequently reported hematologic adverse events included anemia, neutropenia, decreased platelet count and thrombocytopenia, and serious adverse events were reported in approximately one-third of participants. Treatment discontinuation because of treatment-emergent adverse events occurred in 5.5% of participants, and the company said no safety signals for ocular toxicity, peripheral neuropathy, interstitial lung disease or stomatitis were observed.

The company said Rina-S is being evaluated in a broader program that includes four Phase 3 trials in platinum-resistant ovarian cancer, recurrent or progressive endometrial cancer, platinum-sensitive ovarian cancer maintenance therapy and second-line platinum-sensitive ovarian cancer, as well as additional studies in non-small cell lung cancer and advanced gastrointestinal cancers. Genmab is based in Copenhagen and said the safety and efficacy of Rina-S have not been established.