Merck Halts Skin Cancer Drug Trial On High Discontinuation Rate - A Setback in High-Risk Melanoma Treatment

Monday, Merck & Co Inc MRK announced the discontinuation of the vibostolimab and pembrolizumab coformulation arm of the Phase 3 KeyVibe-010 trial. 

The trial evaluates the investigational coformulation of vibostolimab and Keytruda (pembrolizumab) compared to Keytruda alone as adjuvant treatment for patients with resected high-risk melanoma (Stage IIB-IV). 

Also Read: Merck Stock Gains On Its Blockbuster Cancer Drug Keytruda, Raises Annual Outlook.

Data from a pre-planned analysis showed that the primary endpoint of recurrence-free survival (RFS) met the pre-specified futility criteria. 

A higher discontinuation rate of all adjuvant therapy by patients was observed in the coformulation arm versus the Keytruda-only arm, primarily due to immune-mediated adverse experiences. Thus, it is highly unlikely that the trial could achieve a statistically significant improvement in RFS. 

Based on the recommendation of an independent Data Monitoring Committee (DMC), Merck is unblinding the study and recommends that patients receiving the vibostolimab and pembrolizumab coformulation be offered the option to be treated with Keytruda monotherapy. 

Data analysis from this study is ongoing. 

Ongoing Phase 3 studies evaluating the vibostolimab and pembrolizumab coformulation in lung cancer include KeyVibe-003, KeyVibe-006, KeyVibe-007, and KeyVibe-008. 

Interim external data monitoring committee safety reviews have not resulted in safety-related study modifications.

Last week, Merck’s Phase 3 KEYNOTE-B21 trial of Keytruda in combination with chemotherapy as adjuvant treatment, with or without radiotherapy, did not meet its primary endpoint of disease-free survival (DFS) for newly diagnosed, high-risk endometrial cancer patients after surgery with curative intent.

The study’s other primary endpoint of overall survival (OS) was not formally tested since DFS did not reach superiority. 

Read Next: Newly Diagnosed Cervical Cancer Patients – Merck’s Blockbuster Drug Keytruda Plus Chemoradiotherapy Improves Overall Survival.

Price Action: MRK shares are down 1.35% at $128.31 at last check Monday.

Photo via Company