Genmab's Rina-S meets key endpoints in Phase 3 trial for platinum-resistant ovarian cancer

What happened: Genmab reported positive results from the Phase 3 RAINFOL-02 trial of rinatabart sesutecan (Rina-S), its experimental antibody-drug conjugate for platinum-resistant ovarian cancer — cancer that has stopped responding to platinum-based chemotherapy. The trial met its primary endpoint: Rina-S reduced the risk of disease progression or death by 71% versus standard chemotherapy (hazard ratio 0.29; p<0.0001) in the 584-patient intent-to-treat population. It also met the key secondary endpoint of overall survival, cutting the risk of death by 57% (HR 0.43; p<0.0001).

How it works: Rina-S is an antibody-drug conjugate — an engineered antibody that locks onto folate receptor alpha (FRα), a protein found in high amounts on many ovarian cancer cells, and delivers a chemotherapy-like toxin directly into the tumour. In RAINFOL-02 the benefit was seen regardless of how strongly patients' tumours expressed FRα and regardless of prior treatment with mirvetuximab, another FRα-targeting drug — potentially broadening the treatable patient group.

Why it matters: Platinum-resistant ovarian cancer is one of the hardest-to-treat gynaecological cancers, with few effective options and a poor outlook. This is the first Phase 3 readout for Rina-S and a key test for Genmab's late-stage pipeline. The company plans to discuss next steps with regulators worldwide and will submit the full data to a future medical meeting. Rina-S is also being evaluated in several other Phase 3 trials, including endometrial cancer and earlier-line ovarian cancer.

Read more: Genmab, 23 October 2026