LITESPARK‑012 Trial Fails
- Merck said its Phase 3 LITESPARK-012 study in previously untreated advanced renal cell carcinoma missed both primary endpoints, with the belzutifan-lenvatinib-pembrolizumab triplet failing on progression-free and overall survival. - The trial tested Welireg, Lenvima and Keytruda against Lenvima plus Keytruda in first-line kidney cancer, and Merck said the safety profile matched known risks seen with each medicine. - The miss hit a program tied to Merck’s post-Keytruda growth plans and added to scrutiny of late-stage pipeline execution. (merck.com)
Merck said its Phase 3 LITESPARK-012 trial in advanced renal cell carcinoma failed, with a three-drug regimen missing both progression-free survival and overall survival goals. (merck.com) The study tested Welireg, Merck’s brand name for belzutifan, together with Eisai’s Lenvima, or lenvatinib, and Merck’s Keytruda, or pembrolizumab, in previously untreated patients with advanced kidney cancer. Merck compared that triplet against the already approved two-drug combination of Lenvima plus Keytruda. (merck.com) (clinicaltrials.gov) Renal cell carcinoma is the most common form of kidney cancer, and first-line treatment is the first drug regimen patients receive after diagnosis of advanced disease. Progression-free survival measures how long patients live without the cancer worsening, while overall survival tracks how long they live after starting treatment. (clinicaltrials.gov) (targetedonc.com) Belzutifan blocks hypoxia-inducible factor 2 alpha, a protein tumor cells use like a low-oxygen survival switch. Merck has been trying to extend that mechanism into broader kidney cancer settings beyond the drug’s earlier approvals. (merck.com) (fiercepharma.com) Merck said the LITESPARK-012 safety profile was consistent with the known profiles of belzutifan, lenvatinib and pembrolizumab. The company did not release detailed efficacy numbers in the announcement. (merck.com) The result mattered because Keytruda is Merck’s biggest product, and investors have been watching whether new combinations can offset the drug’s eventual patent losses later this decade. Belzutifan has been one of the company’s closely watched follow-on cancer assets. (fiercepharma.com) (merck.com) The failure also landed in a crowded kidney cancer market where two-drug regimens already set a high bar in newly diagnosed advanced disease. Lenvima plus Keytruda had already shown enough benefit for Merck and Eisai to make that doublet a standard first-line option. (merck.com) (clinicaltrials.gov) Eisai issued the same update as Merck, underscoring that the miss affected a shared program built around Lenvima’s role in combination therapy. Neither company said the result changed the approved uses of any of the three medicines. (eisai.com) ([merck.com](https://www.merck
