Genmab’s Rinatabart Sesutecan Continues Success in Advanced Ovarian Cancer Clinical Trials

Genmab has shared positive results from the Phase I/II RAINFOL-01 clinical trial showing that its rinatabart sesutecan (Rina-S), an investigational folate receptor-alpha (FRα)-targeted, TOPO1 antibody-drug conjugate (ADC), achieved an overall response rate (ORR) of 55.6% in heavily pre-treated ovarian cancer (OC) patients regardless of FRα expression levels. Additionally, 1 out of 10 patients experienced disease progression and the median duration of response (mDOR) was not reached.¹

These emerging results are from the B1 cohort of the trial, which is a dose expansion study in patients with histologically or cytologically confirmed advanced OC (epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer). Participants received Rina-S 120 mg/m² every 3 weeks with a median on-study follow-up of 48 weeks. In addition to the 55.6% ORR, the investigational ADC demonstrated a disease control rate (DCR) of 88.9%.

In the Rina-S 100 mg/m² every 3 weeks arm, with a median on study follow-up of 46 weeks, the confirmed ORR was 22.7%, the DCR was 86.4%, and the mDOR was not reached.

In a press release, Elizabeth Lee, MD, a medical oncologist in the gynecologic oncology program at Dana-Farber, said, “The antitumor activity observed in the dose expansion cohort continues to demonstrate the potential for a much-needed treatment option for patients with PROC, who have historically had poor prognosis. I am hopeful that further exploration of Rina-S will lead to advancements in the treatment landscape.”

Judith Klimovsky, MD, executive vice president and chief development officer of Genmab, added, “The updated results reinforce the potential of Rina-S and further validate our development approach in advanced ovarian cancer. We are excited to keep moving forward with the ongoing Phase III trial, to evaluate the potential of Rina-S as a treatment option for patients facing this challenging disease.”

This most recent update from Genmab follows encouraging results of Rina-S announced in September 2024. Initially, the ADC demonstrated a confirmed ORR 50% in OC patients treated with Rina-S at the 120 mg/m² dose once every 3 weeks.²

In a press release from the time, Lee said, “Ovarian cancer presents a significant challenge, especially for those with advanced or recurrent cases, where treatment options and prognosis are often limited. The encouraging Phase I/II data for Rina-S demonstrates the potential for future treatment options for patients. We are looking forward to additional data from tumor-specific dose expansion cohorts.”

According to Genmab, the Phase II RAINFOL-01 and Phase III RAINFOL-02 studies evaluating Rina-S at 120 mg/m² in patients with platinum resistant ovarian cancer are actively recruiting.

References

1. Investigational Rinatabart Sesutecan (Rina-S®) Continues to Show Encouraging Antitumor Activity in Patients with Advanced Ovarian Cancer. News release. Genmab. March 17, 2025. Accessed March 17, 2025. https://www.businesswire.com/news/home/20250317671140/en/Investigational-Rinatabart-Sesutecan-Rina-S-Continues-to-Show-Encouraging-Antitumor-Activity-in-Patients-with-Advanced-Ovarian-Cancer

2. Investigational Rinatabart Sesutecan (Rina-S) Shows Promising Anti-Tumor Activity as Single Agent in Heavily Pretreated Patients with Ovarian and Endometrial Cancers in Phase 1/2 Clinical Trial. News release. Genmab. September 15, 2024. Accessed March 17, 2024. https://www.businesswire.com/news/home/20240913038747/en/Investigational-Rinatabart-Sesutecan-Rina-S-Shows-Promising-Anti-Tumor-Activity-as-Single-Agent-in-Heavily-Pretreated-Patients-with-Ovarian-and-Endometrial-Cancers-in-Phase-12-Clinical-Trial