Adagene Inc. (Nasdaq: ADAG) announced that its investigational therapy ADG126 will be featured in two oral presentations at the 2025 Chinese Society of Clinical Oncology (CSCO) Meeting in Jinan, China, from September 10-14. The presentations will showcase compelling Phase 1b/2 trial results for ADG126 in combination with pembrolizumab for treating microsatellite stable (MSS) colorectal cancer, a historically treatment-resistant cancer type.
Breakthrough Results in Treatment-Resistant Cancer
ADG126, a masked anti-CTLA-4 therapy, achieved an objective response rate of approximately 30% with durable duration of response in refractory/resistant MSS colorectal cancer patients with no liver metastasis. The combination therapy also demonstrated over 80% disease control in this challenging patient population.
The 10 mg/kg cohorts exhibited a median overall survival of 19.4 months, a particularly notable outcome given that refractory MSS CRC patients typically have survival measured in single-digit months with standard therapies. The treatment maintained a favorable safety profile with less than 20% Grade 3 treatment-related adverse events.
Addressing a Critical Unmet Need
MSS colorectal cancer represents approximately 85% of colorectal cancer cases and has historically been considered a "cold tumor" resistant to immunotherapeutic approaches. Traditional immunotherapies typically show minimal effectiveness in this population, making ADG126's results particularly significant.
"Microsatellite stable (MSS) colorectal cancer (CRC) remains one of the cold tumors where effective immunotherapy still remains elusive and I believe anti-CTLA-4 therapy should be part of the solution," said Dr. Heinz-Josef Lenz, Chair of the GI Oncology Program and co-director of the Colorectal Center at University of Southern California's Keck School of Medicine.
Novel Mechanism of Action
ADG126 utilizes Adagene's proprietary SAFEbody precision masking technology to target a unique epitope of CTLA-4 in regulatory T cells (Tregs) within the tumor microenvironment. This approach enables CTLA-4-mediated intratumoral Treg depletion while minimizing on-target off-tumor toxicity in healthy tissues.
Dr. Lenz noted that "the safety profile of ADG126 allows higher, more frequent and repeat doses of anti-CTLA-4 in combination with anti-PD-1 therapy, and has shown promise to significantly improve longer-term survival benefit for MSS CRC patients."
Clinical Presentations
The CSCO presentations will be delivered by leading oncology experts. Dr. Xu Ruihua, Professor and President of Sun Yat-sen University Cancer Center and Chairman of CSCO, will present updated Phase 1b/2 results on Thursday, September 11 at 14:45-15:00 CST. Dr. Lenz will discuss immunotherapy for metastatic colorectal cancer on the same day at 14:00-14:25 CST.
ADG126 represents the first masked anti-CTLA-4 therapy in combination with an approved anti-PD-1 therapy to achieve these response rates in MSS colorectal cancer. The compelling efficacy results, combined with the improved safety profile compared to traditional CTLA-4 inhibitors like ipilimumab, position ADG126 as a potential breakthrough therapy for a substantial patient population currently lacking effective immunotherapy options.
