Genmab (Nasdaq: GMAB) reported that rinatabart sesutecan (Rina-S), its folate receptor alpha (FRα)-targeted antibody-drug conjugate, achieved a confirmed objective response rate of 45.9% and median duration of response of 12.1 months in 109 patients with platinum-resistant ovarian cancer.
The Phase I/II RAINFOL-01 cohort included a heavily pretreated population: 53% had received three or four prior lines of therapy, all had previously received bevacizumab and a taxane, and 33% had received mirvetuximab soravtansine. Genmab reported antitumor activity across FRα expression levels, including in low expressors and non-expressors, and regardless of prior mirvetuximab treatment. That could differentiate Rina-S from AbbVie’s Elahere (mirvetuximab soravtansine), which is approved only for FRα-positive platinum-resistant ovarian cancer selected using an FDA-approved companion diagnostic.
Median progression-free survival was 9.5 months (95% CI: 7.6–11.3), while 51% of responders remained in response at one year. The dataset included five complete responses.
The most common treatment-emergent adverse events were nausea (67.9%), fatigue (57.8%), anemia (57.8%), and neutropenia (57.8%). Treatment discontinuation due to adverse events occurred in 5.5% of patients, and Genmab reported no emerging signals for ocular toxicity, peripheral neuropathy, interstitial lung disease, or stomatitis.