Susana M. Campos, MD, MPH, clinical director of the Division of Gynecologic Oncology and director of Educational Initiatives at Dana-Farber Cancer Institute, and assistant professor of medicine at Harvard Medical School, discussed where rinatabart sesutecan (Rina-S), an investigational folate receptor alpha (FRα)–directed antibody-drug conjugate (ADC), may fit into the endometrial cancer treatment paradigm. Early data show disease control regardless of FRα expression level, and Rina-S is now being evaluated against standard of care in the randomized phase 3 RAINFOL-03 trial (NCT07166094).1,2
In a Satellite Session post-program conversation, Campos explained why a biomarker-independent option matters in a landscape increasingly crowded with immunotherapy and HER2-directed agents.
Transcript:
CancerNetwork: Preliminary data for Rina-S showed strong disease control rates regardless of FRα expression. If approved, where does a biomarker-independent ADC fit into a paradigm that’s already crowded with IO and HER2-targeted agents?
Campos: Rina-S has been quite an interesting drug, targeting the folate receptor. It’s been studied in endometrial cancer in earlier studies and is now being studied in a randomized phase 3 study, [the RAINFOL-03 trial]. It’s a drug that targets a different receptor, and it will have a role as just another drug in the management of [endometrial] cancer if it proves to be efficacious in the randomized phase 3 [trial]. I don’t think we can have enough drugs for these patients. Oftentimes, patients have a performance status that allows the continuation of chemotherapy, so having more agents available to us is by far what we need. When you think back, IO works by 1 mechanism, pembrolizumab and lenvatinib works by another mechanism, not biomarker driven. Fam-Trastuzumab deruxtecan-nxki [Enhertu] targets HER2/neu and has a topoisomerase payload.3 Rina-S also has a topoisomerase inhibitor payload, but what we don’t know is if we target a different marker, whether or not we can still get activity. One has to remember that the expression of HER2/neu on endometrial cancer is not as high as we would like it to be. It’s important to continue to retest it, but it may not be as high. Having more drugs available to these individuals is by far extremely important. We just want options.
References
1. Lee EK, Yeku O, Winer I, et al. 719MO A phase I/II study of rinatabart sesutecan (Rina-S) in patients with advanced ovarian or endometrial cancer. Ann Oncol. 2024;35(suppl 2):S550. doi:10.1016/j.annonc.2024.08.781
2. Study to assess the efficacy and safety of Rina-S compared to treatment of investigator’s choice in participants with endometrial cancer (RAINFOL-03). ClinicalTrials.gov. Updated August 17, 2026. Accessed August 18, 2026. https://tinyurl.com/4b8cucwz
3. Lee JY, Oaknin A, Manso L, et al. Trastuzumab deruxtecan in HER2-expressing gynecologic cancers from DESTINY-PanTumor02: antitumor activity, safety, and exploratory biomarker analyses. J Gynecol Oncol. 2026;37(3):e65. doi:10.3802/jgo.2026.37.e65
