Merck (NYSE:MRK) Eisai announced today that their Phase 3 LITESPARK-012 trial failed to meet its dual primary endpoints, a disappointing result for the pharmaceutical partners’ attempt to establish a new standard of care in first-line kidney cancer treatment.
The study evaluated whether adding Welireg (belzutifan) or an investigational anti-CTLA-4 antibody (quavonlimab) to the existing combination of Keytruda and Lenvima would improve outcomes for patients with advanced clear cell renal cell carcinoma (RCC).
At a pre-specified interim analysis, neither of the intensive combination regimens demonstrated a statistically significant improvement in progression-free survival (PFS) or overall survival (OS) when compared to the current dual-therapy benchmark of Keytruda plus Lenvima.
Despite the clinical failure to meet survival targets, the safety profiles of the experimental regimens remained consistent with previously reported data for the individual agents.
No new or unexpected safety signals were identified during the study.
Merck and Eisai noted that while the primary objectives were not met, a comprehensive evaluation of the data is ongoing.
The trial results represent a strategic hurdle for Merck as it seeks to fortify its oncology franchise ahead of Keytruda’s looming patent expiration later this decade.
Welireg, which was approved by the FDA in 2021 for specific Von Hippel-Lindau disease-associated tumors and later for certain advanced RCC patients, remains a central pillar of Merck's pipeline.
The companies intend to work with investigators to present the full findings of LITESPARK-012 at an upcoming medical meeting to further inform the scientific community’s understanding of HIF-2α and CTLA-4 inhibition in renal cell carcinoma.