On November 9, 2026 Adagene Inc. (Nasdaq: ADAG), a platform-driven, clinical-stage biotechnology company transforming the discovery and development of novel antibody-based therapies, reported completion of enrollment in its randomized Phase 2 dose-optimization trial of muzastotug (ADG126), a masked, anti-CTLA-4 SAFEbody, in combination with Merck’s (known as MSD outside of the United States and Canada) anti-PD-1 therapy, KEYTRUDA (pembrolizumab), in patients with late-line microsatellite stable colorectal cancer (MSS CRC) without liver metastases.

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"Completing enrollment in this randomized trial is an important step toward identifying the dose regimen of muzastotug for the Phase 3 registration trial," said Peter Luo, Ph.D., Chairman and President of R&D at Adagene. "We acknowledge Sanofi’s additional equity investment associated with this trial, which supports continued development of muzastotug in solid tumors, including MSS CRC, where dose-limiting challenges have restricted the use of anti-CTLA-4 therapies. As we look ahead to initial results in the first half of 2027, we hope new data will validate muzastotug’s broad applicability and combinability, further enhanced by its induction and maintenance dosing regimens. This could position muzastotug as a transformative next-generation backbone for combination therapies across multiple indications, in both early- and late-line treatment settings. It could also unlock value in indications where legacy CTLA-4/PD-1 based combinations are already FDA-approved, as well as in historically refractory tumors like MSS CRC."

About the Phase 2 Trial

The randomized Phase 2 trial (NCT05405595) was incorporated into the existing protocol for the Phase 1b/2 study following a 2025 meeting with the U.S. Food and Drug Administration (FDA). The primary endpoint of the Phase 2 trial is overall response rate (ORR), and secondary endpoints include duration of response (DOR), progression-free survival (PFS), and overall survival (OS).

The study enrolled 60 patients, randomized 1:1 into one of two treatment arms evaluating different dose regimens of muzastotug in combination with pembrolizumab. Both arms use induction to rapidly establish activated muzastotug exposure in tumors, followed by maintenance to sustain exposure and potentially improve ORR and OS:

· Arm A: Muzastotug 10 mg/kg every three weeks (Q3W) for four doses, followed by 10 mg/kg every six weeks (Q6W) maintenance

· Arm B: Muzastotug 20 mg/kg Q6W for two doses, followed by 15 mg/kg Q6W maintenance

As previously announced in July 2025, the following elements of the Phase 3 trial design were also confirmed following a meeting with the FDA:

· Patient Population: Trials will enroll late-line patients with MSS CRC without liver metastases, including those with peritoneal metastasis/involvement.

· Phase 3 Trial Design: The FDA agreed with Adagene’s proposed standard-of-care (SOC) control arm for the Phase 3 clinical trial and confirmed that a muzastotug monotherapy arm was not required.

· Phase 3 Endpoints: The primary endpoint of the Phase 3 trial will be OS. Secondary endpoints will include PFS, DOR and ORR.

(Press release, Adagene, NOV 9, 2026, View Source [SID1234674459])