Merck's lung cancer drug combo fails trial in setback for new therapy class

New Delhi: Merck said on Thursday its experimental therapy in combination with Keytruda to treat a type of lung cancer in previously treated patients did not meet the main goal in a mid-stage study.

The results mark another setback in the field of an emerging class of therapies called anti-TIGIT that have triggered a flurry of research and deal activity.

Merck's experimental anti-TIGIT drug vibostolimab in combination with its blockbuster drug Keytruda failed to meaningfully slow disease progression and improve overall survival in study patients with non-small-cell lung cancer that spreads to other organs of the body.

This is yet another failure for Merck's drug combination, after data released in March showed that it was less effective than a generic medicine called docetaxel in a non-blinded arm of the trial testing it in patients with the disease.

Gilead Sciences, Roche and GSK are among the half a dozen drugmakers looking to grab a share of the lucrative cancer market focused on the TIGIT receptor protein believed to help cancer cells thwart immune system detection.

Last year, data from Gilead and its co-developer Arcus Biosciences' combo therapy and Roche's lung cancer therapy fell short of expectations.

However, Roche had inadvertently published positive lung cancer drug trial data from an interim analysis earlier this year, raising hopes among investors.

Merck's vibostolimab works by selectively binding itself to TIGIT, a receptor on immune system cells that normally serves to prevent a misguided immune attack against healthy cells.

Some cancers have developed a mechanism that exploits TIGIT to continue to grow unnoticed by cell-killing immune cells, prompting intense research into using anti-TIGITs in combination with other cancer drugs.

Separately, Merck on Thursday said it will discontinue a late-stage study of its combination therapy using already approved cancer drugs Keytruda and Lynparza to treat patients with a type of lung cancer, as the data from interim analysis was disappointing.