Genmab's Rina-S cuts death risk 57% in platinum-resistant OC

Phase 3 RAINFOL-02 showed Rina-S reduced disease progression risk by 71% and death risk by 57% versus chemotherapy in platinum-resistant ovarian cancer.

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A medical IV pump with clear tubing is mounted on a pole in a bright hospital room, featuring a window, potted plant, and a bed in the background.

Genmab has reported that its antibody-drug conjugate rinatabart sesutecan (Rina-S) met both the primary endpoint of progression-free survival and the key secondary endpoint of overall survival in the Phase 3 RAINFOL-02 trial, pitting the drug against investigator's choice chemotherapy in patients with platinum-resistant ovarian cancer regardless of folate receptor alpha expression level or prior treatment history.

In the intent-to-treat population of 584 randomised patients, Rina-S reduced the risk of disease progression or death by 71% versus chemotherapy (hazard ratio 0.29; 95% CI, 0.23–0.37; p less than 0.0001). The overall survival benefit was also statistically significant, with a 57% reduction in the risk of death (HR 0.43; 95% CI, 0.31–0.59; p less than 0.0001). Results were consistent in the primary analysis set, which restricted enrolment to patients with higher FRα expression or prior mirvetuximab treatment, with hazard ratios of 0.33 and 0.44 for PFS and OS respectively.

Genmab said the safety profile was consistent with previously observed data from the Rina-S programme, with no new signals identified.

Clinical context

Angeles Alvarez Secord, lead investigator for the Gynecologic Oncology Group and professor at the Duke Cancer Institute, said the results "set a new benchmark" in platinum-resistant ovarian cancer, a setting where patients face limited options and poor prognosis after failure of platinum-based regimens. The magnitude of the PFS benefit, expressed as an HR of 0.29 in the all-comers population, is notably large by the standards of later-line gynaecologic oncology trials.

A critical feature of the trial design is that efficacy was demonstrated regardless of FRα expression level. This broadens the potential eligible population significantly beyond that addressed by Elahere (mirvetuximab soravtansine), ImmunoGen's approved FRα-targeted ADC, which is licensed for use in patients with high FRα expression. If regulatory agencies accept the all-comers framing, Rina-S could address a substantially wider segment of the platinum-resistant ovarian cancer population.

Regulatory path and pipeline

Genmab said it intends to engage with regulators worldwide to discuss potential next steps, and that full data will be submitted for presentation at a future medical meeting. The company is hosting an investor update on 28 October 2026.

RAINFOL-02 is the first Phase 3 readout from the Rina-S programme, which now spans five Phase 3 trials across platinum-resistant and platinum-sensitive ovarian cancer, endometrial cancer, and first-line ovarian cancer maintenance therapy. Additional Phase 2 investigations are ongoing in non-small cell lung cancer and advanced gastrointestinal cancers, reflecting the breadth of FRα expression across solid tumour types.

The ADC field has seen considerable activity in gynaecologic oncology, with trastuzumab deruxtecan (Enhertu) approved in HER2-positive endometrial cancer and multiple competitors advancing FRα and folate receptor-targeted programmes. A successful regulatory submission for Rina-S would position Genmab as a significant commercial player in a competitive but high-value oncology segment, consistent with the company's stated ambition to lead in gynaecologic cancers.

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