Adagene masked CTLA-4 shows breakthrough potential in colorectal cancer

Adagene (NASDAQ:ADAG) reported updated clinical data for its lead "SAFEbody" candidate, muzastotug, revealing a significant dose-dependent response in patients with treatment-resistant colorectal cancer—a population that has traditionally been unresponsive to immunotherapy.

The updated Phase 1b/2 results focused on muzastotug (ADG126) in combination with Merck’s anti-PD-1 therapy, pembrolizumab, for patients with late-line microsatellite stable (MSS) colorectal cancer (CRC) without liver metastases.

The data highlights a marked improvement in efficacy at higher doses: the confirmed objective response rate (ORR) climbed to 31% in the 20 mg/kg cohort, more than double the 13% observed at the 10 mg/kg dose level.

Survival metrics also trended favorably with the higher dose.

Median progression-free survival (PFS) reached 6.7 months for the 20 mg/kg group, compared to 4.8 months for those on the lower dose.

For the 10 mg/kg cohort—which has a longer follow-up period—median overall survival (mOS) was reported at 19.8 months, a robust figure for a patient population that has typically exhausted all standard chemotherapy options.

Perhaps most critically for the CTLA-4 class, which has historically been hindered by severe systemic toxicity, muzastotug continued to demonstrate a superior safety profile.

Adagene reported no dose-limiting toxicities (DLTs) and no Grade 4 or 5 treatment-related adverse events (TRAEs).

This "masking" technology allows the drug to remain inactive in the bloodstream and trigger only within the tumor microenvironment, enabling the use of higher, more effective doses.

The company is currently enrolling patients in a randomized Phase 2 study, with results expected in the first half of 2027.

Adagene’s FDA Fast Track designation for this program is expected to streamline future regulatory submissions as the company seeks to establish muzastotug as a cornerstone of combination immunotherapy in "cold" tumors.