Adagene's ADG126-Keytruda Combination Shows Promising 33% Response Rate in MSS Colorectal Cancer Trial

• Updated Phase 1b/2 trial data reveals ADG126 combined with pembrolizumab achieved a 33% overall response rate in microsatellite stable colorectal cancer patients, showing improvement from previous 23% response rate.
• All responding patients remain on treatment with maintenance doses of either 10 mg/kg every 3 or 6 weeks, demonstrating sustained therapeutic effect.
• The study implemented flexible dose modifications to optimize individual patient treatment outcomes, with final time-to-event data expected in 2025.

In a significant development for colorectal cancer treatment, Adagene has reported enhanced efficacy data for its ADG126 therapy when combined with Merck's pembrolizumab (Keytruda) in patients with microsatellite stable colorectal cancer (MSS CRC). The updated results were presented at the ASCO Gastrointestinal Cancers Symposium in San Francisco.

The Phase 1b/2 open-label, multicenter study evaluated escalating doses of ADG126 in combination with pembrolizumab, focusing on MSS CRC patients without liver and peritoneum metastases. The latest data showed an improved overall response rate (ORR) of 33% using a modified dosing regimen that includes a 20 mg/kg loading dose followed by 10 mg/kg every three weeks (Q3W).

Enhanced Treatment Response

This new response rate marks a significant improvement from the previously reported 23% ORR, which included four confirmed partial responses and one unconfirmed partial response at the initial 10 mg/kg Q3W dose level. Notably, all patients who responded to the treatment continue to receive therapy, maintaining doses at either 10 mg/kg Q3W or 10 mg/kg every six weeks (Q6W) in combination with pembrolizumab.

Adaptive Treatment Strategy

The trial protocol incorporated flexibility in dose modifications, allowing investigators to manage toxicity effectively. This adaptive approach enabled healthcare providers to tailor treatment regimens to individual patient needs, potentially contributing to improved response durability. The strategy reflects a growing trend in oncology toward personalized medicine and adaptive trial designs.

Ongoing Evaluation

While the initial results are encouraging, the full impact of this combination therapy remains to be determined. Time-to-event endpoints, which will provide crucial information about the treatment's long-term effectiveness, are scheduled to be reported when the data matures in 2025. These endpoints typically include progression-free survival and overall survival metrics, which are essential for understanding the therapy's full clinical benefit.