SUZHOU, China, February 14, 2026 /PRNewswire/ — Alphamab Oncology (stock code: 9966.HK) announced that the first patient successfully received one dose in the Phase III clinical study (Study ID: JSKN003-005) of HER2-targeting biparatopic antibody-drug conjugate (ADC) JSKN003, for the treatment of HER2-positive advanced colorectal cancer (CRC). JSKN003 is independently developed by the Company and co-developed with JMT-Bio Technology Co., Ltd., a wholly-owned subsidiary of CSPC Pharmaceutical Group Co., Ltd. (stock code: 1093.HK).
Colorectal cancer is one of the most common malignancies worldwide. China experiences a high incidence of CRC, with more than 500,000 new cases diagnosed each year. Around 83% of patients are initially diagnosed at an advanced stage and around 44% already have distant metastases in organs such as the liver or lungs. Despite advances in systemic therapies, the 5-year survival rate of patients with metastatic CRC remains less than 20%, indicating a poor prognosis. There are currently no HER2-targeted treatments approved in China for CRC. For patients with advanced HER2-positive CRC who have failed prior treatments with oxaliplatin, fluorouracil, and irinotecan, the median progression-free survival (mPFS) of approved treatments is only 2.0 to 3.7 months, and the median overall survival (mOS) is approximately 7 to 10 months. There remains a significant unmet clinical need in this patient population. Early clinical data for JSKN003 are promising and JSKN003 has been granted Breakthrough Therapy Designation by the National Medical Products Administration’s (NMPA) Center for Drug Evaluation (CDE) for this indication. According to data presented at the European Society for Medical Oncology (ESMO) Congress 2025, JSKN003 demonstrated an objective response rate (ORR) of 68.8% and mPFS of 11.04 months in 32 patients with HER2-positive advanced colorectal cancer, showing a clear therapeutic advantage over existing therapies.
JSKN003-005 is a randomized, open-label, controlled, multicenter phase III clinical study designed to evaluate the efficacy and safety of JSKN003 compared to the investigator’s chosen regimen (regorafenib/fruquintinib/trifluridine tipiracil) in patients with advanced HER2-positive CRC who have failed prior treatment with oxaliplatin, fluorouracil and irinotecan. The primary endpoint is PFS assessed by blinded independent central review (BICR) according to RECIST v1.1. Secondary endpoints include OS, as well as investigator-assessed PFS and ORR, disease control rate (DCR), duration of response (DOR), time to response (TTR), and other BICR/investigator-assessed endpoints per RECIST v1.1. The rapid progression of this study marks a critical milestone in the development of JSKN003 for colorectal cancer and is expected to provide patients with a new treatment option.
About JSKN003
JSKN003 is expanded by site-specific conjugation with the Fc glycans of anbenitamab, resulting in a homogeneous and stable ADC with a DAR of 4. JSKN003 binds to two HER2 epitopes on tumor cells and releases topoisomerase I inhibitors through cellular endocytosis, exerting antitumor effects.
Compared to similar ADCs, JSKN003 demonstrates better serum stability, reduced hematologic toxicity, and stronger tumor inhibition and bystander effect, resulting in a significantly wider therapeutic window.
Multiple registration studies of JSKN003 are underway, including trials in HER2-positive breast cancer (BC), platinum-resistant ovarian cancer (PROC), HER2-low BC cancer, and HER2-positive colorectal cancer (CRC).
JSKN003 received Orphan Drug Designation (ODD) by the United States Food and Drug Administration (FDA) for gastric cancer (GC) and gastroesophageal junction (GEJ) cancer, received Fast Track Designation (FTD) by the FDA for the treatment of recurrent epithelial ovarian cancer, primary peritoneal cancer or fallopian tube cancer (PROC), advanced or metastatic platinum-resistant, not limited by HER2 expression, received Breakthrough Therapy Designation (BTD) by the FDA for the treatment of patients with HER2-expressing PROC who have previously received treatment with bevacizumab. The National Medical Products Administration (NMPA) also granted it two BTDs for advanced PROC and HER2-positive CRCs that have failed prior treatment with oxaliplatin, fluorouracil, and irinotecan.
In September 2024, the Company entered into a licensing agreement with JMT-Bio Technology Co., Ltd. (“JMT-Bio”), a wholly owned subsidiary of CSPC Pharmaceutical Group Co., Ltd. (“CSPC”) (stock code: 1093.HK). JMT-Bio has obtained exclusive license and sublicense rights to develop, sell, offer for sale and commercialize JSKN003, for tumor-related indications in mainland China (excluding Hong Kong, Macau or Taiwan). Alphamab retains exclusive production rights for JSKN003.
About Alphamab Oncology
Alphamab Oncology (stock code: 9966.HK) is an innovative biopharmaceutical company focused on oncology. Leveraging proprietary platforms, including single-domain antibodies, bispecific antibodies, glycan-specific conjugations, linker payloads, dual-payload ADCs and high-concentration subcutaneous formulations, the Company has built a differentiated and globally competitive pipeline, spanning leading ADC, bispecific antibody and single-domain antibody candidates.
One product has received marketing authorization: Envafolimab (KN035, brand name: 恩维达®), the world’s first subcutaneously injected PD-(L)1 inhibitor, providing greater convenience and accessibility in cancer treatment. The NMPA has accepted the New Drug Application for KN026 (Anbenitamab Injection), a HER2 bispecific antibody, for second-line or later HER2-positive gastric cancer. Four bispecific ADC candidates have entered clinical stages, and next-generation ADC pipelines, such as dual-payload ADCs, are progressing rapidly. The company has established strategic partnerships with organizations such as CSPC, ArriVent and Glenmark, spanning both product development and technology platforms.
Our overarching mission is to make cancer manageable and curable by addressing unmet clinical needs in oncology. Alphamab Oncology is continuously dedicated to developing effective, safe and globally competitive anti-tumor drugs, bringing innovative anti-cancer therapies in China to benefit patients around the world.
SOURCE Alphamab Oncology
