What safety findings were reported?
The most common treatment-emergent adverse events (TEAEs) were fatigue (57.8%) and low-grade gastrointestinal events, including nausea (67.9%), vomiting (36.7%), constipation (26.6%), decreased appetite (23.9%), and abdominal pain (18.3%). Among the most frequent hematologic TEAEs were anemia (57.8%), neutropenia (57.8%), decreased platelet counts (34.9%), and thrombocytopenia (34.9%).
Serious adverse events were reported in approximately one-third of participants, and 5.5% discontinued treatment because of TEAEs. No safety signals for ocular toxicity, peripheral neuropathy, interstitial lung disease, or stomatitis were observed.
How was part C of RAINFOL-01 designed?
Part C evaluated Rina-S at 120 mg/m² every 3 weeks as monotherapy in patients with platinum-resistant high-grade serous ovarian, primary peritoneal, or fallopian tube cancer. Eligible patients had received 1 to 3 prior lines of therapy, though those who received mirvetuximab as their last prior therapy could have had up to 4 prior lines. More than half of patients (53%) had received 3 or 4 prior lines, and all patients had received prior bevacizumab and a taxane. A total of 49.5% had received a PARP inhibitor, and 33% had received prior mirvetuximab soravtansine-gynx, a different FRα-directed ADC approved by the FDA for FRα-positive PROC.3
RAINFOL-01 is an open-label, multicenter phase 1/2 study evaluating Rina-S every 3 weeks at various doses in selected solid tumors, including tumors across a range of FRα expression levels.¹
What is next for rinatabart sesutecan?
Rina-S is composed of a human monoclonal antibody directed at FRα, a hydrophilic protease-cleavable linker, and exatecan, a TOPO1 inhibitor payload. The development program includes 4 phase 3 trials: RAINFOL-02 in PROC (NCT06619236), RAINFOL-03 in recurrent or progressive endometrial cancer (NCT07166094), RAINFOL-04 in maintenance therapy for platinum-sensitive ovarian cancer (NCT07225270), and RAINFOL-07 in second-line platinum-sensitive ovarian cancer (NCT07564141). Phase 2 trials are also evaluating Rina-S in non–small cell lung cancer (RAINFOL-05; NCT07288177) and advanced gastrointestinal cancers (RAINFOL-09; NCT07539311).
“The late-breaking results presented today add an important layer of evidence to the growing clinical experience with Rina-S in patients with [PROC],” stated Tahamtan Ahmadi, MD, PhD, executive vice president, chief medical officer, and head of experimental medicines at Genmab, in the press release.1
References
- Genmab announces rinatabart sesutecan (Rina-S®) phase 2 RAINFOL™-01 results demonstrated durable and clinically meaningful responses in patients with platinum-resistant ovarian cancer. News release. Genmab A/S. October 3, 2026. Accessed October 5, 2026. https://tinyurl.com/43ta993r
- Lee EK, Yeku O, Winer I, et al. Rinatabart sesutecan (Rina-S®) for patients with advanced ovarian cancer: results from dose expansion cohort B1 of a phase 1/2 study. Presented at: 2025 Society of Gynecologic Oncology Annual Meeting on Women’s Cancer; March 14-17, 2025; Seattle, WA. Abstract 809034.
- FDA approves mirvetuximab soravtansine-gynx for FRα positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer. News release. FDA. March 22, 2024. Accessed October 5, 2026. https://tinyurl.com/2apx6e5s
