Merck And Eisai’s WELIREG + LENVIMA Combo Achieves Key Milestone In Advanced Renal Cell Carcinoma Trial

Merck and Eisai have announced that their Phase 3 LITESPARK-011 trial met one of its primary endpoints, demonstrating a significant improvement in progression-free survival (PFS) with the combination of WELIREG® (belzutifan) and LENVIMA® (lenvatinib) compared to cabozantinib in patients with advanced renal cell carcinoma (RCC) whose disease had progressed following prior anti-PD-1/L1 therapy. The combination also achieved a statistically significant improvement in objective response rate (ORR), while showing a positive trend toward overall survival (OS), which will be evaluated further in future analyses.

“Despite recent treatment advances, many patients with advanced RCC may still experience disease progression following treatment with a PD-1/L1 inhibitor,” said Dr. M. Catherine Pietanza, Vice President, Global Clinical Development, Merck Research Laboratories. “These positive results from LITESPARK-011 show the potential of this novel combination to reduce the risk of disease progression or death for patients who are in need of innovative options on or after treatment with immunotherapy.”

The safety profile of the WELIREG plus LENVIMA regimen remained consistent with prior studies of each individual therapy, and no new safety signals were observed. These promising results underscore the potential of combining a first-in-class HIF-2α inhibitor with a multi-targeted tyrosine kinase inhibitor to address the treatment challenges in previously treated RCC. Merck and Eisai plan to engage with regulatory authorities globally and present the findings at an upcoming medical conference.

“We are encouraged by the data observed in the LITESPARK-011 trial, which bolster our belief in the role of LENVIMA in various combinations as a treatment option for patients impacted by advanced RCC,” said Dr. Corina Dutcus, Senior Vice President, Oncology Global Clinical Development Lead at Eisai. “These results further demonstrate Eisai’s commitment to people living with advanced RCC and invigorate our mission to address the unmet needs of patients with difficult-to-treat cancers. We look forward to sharing these investigational findings with regulatory authorities worldwide, with the goal of bringing this treatment option to patients as soon as possible. We extend our heartfelt gratitude to the patients, caregivers and investigators for their participation in this study, and for helping us move this important research forward.”

The LITESPARK-011 trial is part of Merck’s broader late-stage clinical program evaluating WELIREG across several tumour types, including RCC, pheochromocytoma, paraganglioma, and von Hippel-Lindau (VHL) disease-associated neoplasms. Additional studies, such as the Phase 3 LITESPARK-012, are assessing WELIREG in combination with KEYTRUDA® (pembrolizumab) and LENVIMA in first-line RCC. WELIREG, KEYTRUDA, and LENVIMA already hold approvals across major markets for various advanced cancers, further strengthening the collaboration’s oncology portfolio.