Genmab has shared the first data on rinatabart sesutecan (Rina-S) in advanced endometrial cancer. The biotech reported a 50% unconfirmed response rate, beating the expectations of William Blair analysts to boost confidence in the program ahead of its move into phase 3. Rina-S is a FRα-directed ADC that Genmab picked up last year in its $1.8 billion takeover of ProfoundBio. At the time, Rina-S was in a phase 1/2 trial in ovarian cancer and Genmab outlined an opportunity worth $1 billion or more. Subsequently, the biotech identified a broader set of target indications and dialled up its valuation of the opportunity to $2 billion or more. Endometrial cancer represents a meaningful piece of the opportunity, making the publication of the first clinical data in this setting a key early test of Genmab’s growing ambitions for the ADC. Rina-S passed the test. Ahead of the American Society of Clinical Oncology (ASCO) Annual Meeting that begins next week, Genmab reported unconfirmed response rates of 50% and 45.5%, respectively, in the lower and higher dose cohorts. The biotech saw two complete responses at the lower dose. Around 80% of the responses were ongoing in both cohorts as of the cutoff. The patients had received one to eight lines of prior therapies before joining the trial.

Full report : Genmab’s Rina-S Data Promises Efficacy and Strategic Growth Potential in Endometrial Cancer Treatment.