Exelixis teams up with Merck for CRC trial

New deal, same high-stakes biotech roulette

Exelixis just announced a clinical development collaboration with Merck for STELLAR-316, a planned phase 3 pivotal trial in patients with resected stage II/III colorectal cancer. The setup: Merck will supply KEYTRUDA QLEX for subcutaneous administration, and Exelixis will pair it with zanzalintinib.

Why you should care

This isn’t the kind of headline that sends a drug straight to the finish line, but it does matter. When two big-name biopharma players join forces on a late-stage study, it can be a sign the combo has real commercial ambition — and real confidence behind it. If the trial works, it could expand zanzalintinib’s opportunity beyond the solo-act life.

The investor angle

For Exelixis, this is about building optionality. Cancer drug development is basically a long game of “show me the data,” and a Merck collaboration can add credibility, visibility, and potentially a bigger future market if the regimen lands. The market will now be watching for trial design details, timelines, and eventually whether the combo can deliver the kind of results that matter in oncology.

Big picture: biotech partnerships are part science experiment, part strategic dating app. Exelixis just swiped right on a heavyweight.