By Colin Kellaher


Merck & Co. has ended part of a late-stage study of a co-formulation of its blockbuster cancer drug Keytruda in certain skin-cancer patients because the study was likely to fail.

Merck, which is studying the co-formulation of Keytruda with its investigational anti-TIGIT antibody vibostolimab compared to Keytruda alone as adjuvant treatment for patients with resected high-risk melanoma, on Monday said it ended the co-formulation arm after data showed that the primary endpoint of recurrence-free survival had met pre-specified futility criteria.

The Rahway, N.J., drugmaker said a higher rate of discontinuation of all adjuvant therapy by patients in the co-formulation arm, primarily due to immune-mediated adverse experiences, made it highly unlikely that the trial could achieve a statistically significant improvement in recurrence-free survival.

Merck said it is recommending that patients receiving the co-formulation be offered the option to be treated with Keytruda monotherapy.

Merck is studying Keytruda, a cancer drug that harnesses a patient's immune system to fight tumors, in a raft of trials across a wide variety of cancers and treatment settings, including a development program evaluating the vibostolimab co-formulation alone and in combination with other agents.

Keytruda, which is approved in dozens of indications worldwide, generated sales of more than $25 billion last year.


Write to Colin Kellaher at colin.kellaher@wsj.com


(END) Dow Jones Newswires

05-13-24 0800ET