Merck's colorectal cancer therapy fails late-stage trial

(Reuters) -Merck said on Wednesday a combination of its experimental drug and blockbuster therapy Keytruda failed a late-stage trial testing it in previously treated patients with a type of colorectal cancer.

This is the latest failure in a set of trials studying a combination involving Keytruda at a time the drugmaker seeks to expand its use in types of cancers not yet treated by immunotherapies while facing a loss of patent protection for the drug at the end of the decade.

In the past few months, Merck has discontinued trials that tested a Keytruda combination in skin or lung cancer.

The trial for colorectal cancer enrolled 441 patients, where the participants who took the experimental drug favezelimab along with Keytruda did not show significant improvement in overall survival compared to those on the standard-of-care treatment.

Colorectal cancer, which develops in the colon or rectum, affects more than 150,000 people in the United States annually, according to data from the National Institutes of Health.

Favezelimab works by preventing a protein called LAG-3 from binding to certain molecules on tumor cells. This activates the body's immune response and can reduce tumor growth.

The favezelimab-Keytruda combination is also being evaluated as a treatment for types of blood disorders and solid tumors.

(Reporting by Christy Santhosh; Editing by Varun H K and Shilpi Majumdar)