FDA grants breakthrough therapy designation to R-DXd for platinum-resistant ovarian and related cancers

Raludotatug deruxtecan is a specifically engineered, potential first-in-class CDH6-directed DXd antibody drug conjugate (ADC) discovered by Daiichi Sankyo

Daiichi Sankyo and Merck announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation (BTD) to raludotatug deruxtecan (R-DXd) for the treatment of adult patients with platinum-resistant epithelial ovarian, primary peritoneal, or fallopian tube cancers expressing CDH6 who have received prior treatment with bevacizumab.

Raludotatug deruxtecan is a specifically engineered, potential first-in-class CDH6-directed DXd antibody drug conjugate (ADC) discovered by Daiichi Sankyo and being jointly developed with Merck. This marks the first Breakthrough Therapy Designation for raludotatug deruxtecan, the second since the start of the Daiichi Sankyo and Merck collaboration, and the fifteenth Breakthrough Therapy Designation granted by the FDA across Daiichi Sankyo’s oncology portfolio.

The FDA’s Breakthrough Therapy Designation is designed to expedite the development and review of medicines that may offer substantial improvements over existing treatments for serious conditions with high unmet need. The designation for raludotatug deruxtecan is based on data from a phase 1 trial and the ongoing REJOICE-Ovarian01 phase 2/3 trial. Findings from subgroup analyses of the phase 1 study have been presented at major international conferences, including the 2023 European Society for Medical Oncology Congress, the 2024 Society for Gynecologic Oncology Annual Meeting on Women’s Cancer, and the 2025 European Society for Medical Oncology Gynaecological Cancers Congress.

“Patients have limited treatment options once ovarian cancer becomes resistant to platinum-based chemotherapy, highlighting the urgent need for new therapies that can improve outcomes,” said Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo. “This Breakthrough Therapy Designation represents a significant step forward in our mission to advance raludotatug deruxtecan as a novel treatment option for patients with CDH6-expressing platinum-resistant ovarian, primary peritoneal, or fallopian tube cancers previously treated with bevacizumab.”

Eliav Barr, MD, Senior Vice President, Head of Global Clinical Development and Chief Medical Officer, Merck Research Laboratories, added, “The FDA’s designation reflects our commitment to delivering innovative research for patients affected by women’s cancers. Raludotatug deruxtecan has the potential to become an important treatment option for patients with these difficult-to-treat cancers, and we look forward to sharing additional data from the REJOICE-Ovarian01 trial at an upcoming medical meeting as we continue our collaboration with the FDA.”