FDA Grants Breakthrough Therapy Designation to Rina-S for Endometrial Cancer Treatment.

Genmab's Rina-S has been granted Breakthrough Therapy Designation by the US FDA for the treatment of recurrent or progressive endometrial cancer in patients with disease progression on platinum-containing regimens and PD-(L)1 therapy. The designation is based on encouraging response data from the Phase 1/2 RAINFOL-01 trial. Rina-S will be evaluated further in a planned Phase 3 trial.

Copenhagen, Denmark — Genmab A/S (Nasdaq: GMAB) announced today that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation (BTD) to rinatabart sesutecan (Rina-S®), an investigational folate receptor alpha (FRα)-directed, TOPO1-inhibitor antibody-drug conjugate (ADC), for the treatment of adult patients with recurrent or progressive endometrial cancer (EC) who have disease progression on or following prior treatment with a platinum-containing regimen and a PD-(L)1 therapy. This designation aims to expedite the development and review of investigational medicines by the U.S. FDA for serious or life-threatening diseases where preliminary clinical evidence shows substantial improvements over available therapies.

The designation was supported by previously published results from the endometrial cancer monotherapy dose expansion B2 cohort of the multi-part, Phase 1/2 RAINFOL™-01 trial (NCT05579366), evaluating the safety and efficacy of Rina-S in solid tumors. In the B2 cohort, 64 patients with heavily pretreated advanced or recurrent EC whose disease had progressed on or after an anti-PD-(L)1 and platinum-based chemotherapy were enrolled and treated with Rina-S. The results were presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting.

Rina-S continues to be evaluated as a single-agent in patients with advanced EC in the Phase 1/2 RAINFOL™-01 trial and will be further evaluated in a planned Phase 3 trial. This trial is part of a growing portfolio of clinical trials for Rina-S, which includes the ongoing Phase 1/2 RAINFOL-01 trial, the ongoing Phase 3 RAINFOL-02 trial (NCT06619236) in ovarian cancer, and several planned trials to evaluate Rina-S as a potential treatment option for a variety of tumor types.

Endometrial cancer (EC) is the second most prevalent gynecologic cancer globally, with increasing incidence and mortality rates. Patients with advanced or recurrent EC have a relatively poor prognosis and treatment options are limited for those patients who have progressed following treatment with chemotherapy and immune checkpoint inhibitor. FRα is overexpressed on multiple tumors, including EC, making it a promising therapeutic target. Anti-tumor activity with Rina-S was observed across a broad range of FRα expression, and there are currently no approved FRα-directed therapies approved for the treatment of endometrial cancer.

Rinatabart sesutecan (Rina-S; GEN1184) is an investigational ADC composed of a novel human monoclonal antibody directed at folate receptor α (FRα), a novel hydrophilic protease-cleavable linker, and exatecan, a topoisomerase I inhibitor payload. The clinical trial program for Rina-S continues to expand, including ovarian, endometrial, and other cancers of unmet need.

Genmab, established in 1999, is an international biotechnology company with a core purpose of guiding its unstoppable team to strive toward improving the lives of patients with innovative and differentiated antibody therapeutics. The company's pipeline includes bispecific T-cell engagers, antibody-drug conjugates, next-generation immune checkpoint modulators, and effector function-enhanced antibodies.

References:
[1] https://www.businesswire.com/news/home/20250825239262/en/Genmab-Receives-FDA-Breakthrough-Therapy-Designation-for-Rinatabart-Sesutecan-Rina-S-in-Advanced-Endometrial-Cancer-EC
[2] https://www.stocktitan.net/news/GMAB/genmab-receives-fda-breakthrough-therapy-designation-for-rinatabart-t9nmztar07wt.html