Genmab reported Part C results from the Phase I/II RAINFOL‑01 trial of Rina‑S (rinatabart sesutecan) in 109 patients with platinum‑resistant ovarian, peritoneal or fallopian tube cancer. The confirmed ORR was 45.9% (including five CRs); median DOR was 12.1 months and median PFS was 9.5 months. Activity was seen across FRα expression levels and regardless of prior mirvetuximab; safety was manageable with ~33% experiencing serious adverse events and 5.5% discontinuing due to toxicity.
Genmab: Rina‑S Produces 45.9% ORR and Durable Responses in Platinum‑Resistant Ovarian Cancer
The trial found a confirmed objective response rate of 45.9%
Genmab has released results from Part C of the Phase I/II RAINFOL‑01 study evaluating rinatabart sesutecan (Rina‑S; GEN1184) in 109 patients with platinum‑resistant high‑grade serous ovarian, primary peritoneal, or fallopian tube cancer.
Rina‑S is an investigational antibody‑drug conjugate (ADC) composed of a human monoclonal antibody targeting folate receptor alpha (FRα), a hydrophilic protease‑cleavable linker, and an exatecan topoisomerase I inhibitor payload designed to deliver potent cytotoxic activity to FRα‑expressing tumor cells.
Key Efficacy Results
At the evaluated dose of 120 mg/m² every three weeks, the trial reported a confirmed objective response rate (ORR) of 45.9%, including five complete responses. The median duration of response (DOR) was 12.1 months, with 51% of responders remaining in response at one year. Median progression‑free survival (PFS) was 9.5 months.
Activity Across Subgroups
Antitumour activity was observed across all levels of FRα expression and occurred irrespective of prior exposure to mirvetuximab, suggesting potential benefit in a broad platinum‑resistant population.
Patient Profile and Follow‑Up
The analysis included 109 patients. Eligible participants had received between one and three prior lines of therapy, except patients whose most recent treatment was mirvetuximab, who could have had up to four prior lines; overall, 53% had three or four prior lines. All patients had previously received bevacizumab and a taxane; 49.5% had received a PARP inhibitor and 33% had been treated with mirvetuximab soravtansine. Median follow‑up exceeded one year.
Safety
The safety profile was manageable. The most common adverse events were fatigue and Grade 1–2 gastrointestinal symptoms (nausea, vomiting, decreased appetite, constipation, abdominal pain). Frequent hematologic events included neutropenia, anemia and decreased platelet counts (thrombocytopenia). Serious adverse events were reported in approximately one‑third of participants, and 5.5% discontinued treatment because of adverse events. Importantly, no safety signals were observed for interstitial lung disease (ILD), ocular toxicity, peripheral neuropathy or stomatitis.
“These findings, including the observed antitumour activity, duration of response, and the first progression‑free survival data reported for the programme, as well as the manageable tolerability, reinforce the potential of Rina‑S. As our Phase III programme continues to advance, the results further inform our evaluation of Rina‑S as a potential treatment option for patients with gynaecologic cancers.”
— Tahamtan Ahmadi, Executive Vice‑President and Chief Medical Officer, Head of Experimental Medicines, Genmab
Separately, Genmab reported in June 2026 that a Phase III trial of a combination regimen incorporating its bispecific T‑cell engager (BiTE) approach with Epkinly met its primary endpoint in adult patients with relapsed or refractory diffuse large B‑cell lymphoma (DLBCL).
These Part C data support continued development of Rina‑S and will inform the ongoing Phase III programme.
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