Objective:

Report Phase 1/2 RAINFOL-01 findings on the activity and safety of rinatabart sesutecan (Rina-S) in platinum-resistant ovarian, primary peritoneal, or fallopian tube cancer.

Approach:

• Study design: Open-label, multicenter Phase 1/2 trial evaluating Rina-S in patients with selected solid tumors.
• Participants: The reported cohort included 109 patients with platinum-resistant high-grade serous ovarian, primary peritoneal, or fallopian tube cancer who had received one to three prior treatment lines, or up to four if their most recent treatment was mirvetuximab.
• Treatment: Rina-S is an FRalpha-targeted antibody-drug conjugate carrying the topoisomerase I inhibitor exatecan.

Key Findings:

• Confirmed objective response rate was 45.9%, including five complete responses.
• Median duration of response was 12.1 months; 51% of responders remained in response at one year.
• Median progression-free survival was 9.5 months.
• Antitumor activity was reported across FRalpha expression levels, including low or absent expression, and regardless of prior mirvetuximab treatment. Among patients previously treated with mirvetuximab, median duration of response was 13.1 months.
• Commonly reported adverse events included fatigue, gastrointestinal symptoms, anemia, neutropenia, and thrombocytopenia. Treatment-related adverse events led to discontinuation in 1.8% of patients.
• The study reported no safety signals for ocular toxicity, peripheral neuropathy, interstitial lung disease, or stomatitis.

Interpretation:

Lead investigator Elizabeth K. Lee described the responses as clinically meaningful and durable and said further studies are needed to determine Rina-S’s role in ovarian cancer treatment.

Limitations:

• The findings are from a Phase 1/2 trial; the context does not provide a comparator group or detailed subgroup response estimates.
• The reported results concern a selected cohort of 109 patients and do not establish comparative efficacy.

Conclusion:

A randomized Phase 3 trial, RAINFOL-02, is enrolling patients.

Sources:

• Article context supplied in the prompt