SUZHOU, China, Feb. 14, 2026 /PRNewswire/ -- Alphamab Oncology (stock code: 9966.HK) announced that the first patient has been successfully dosed in the Phase III clinical study (Study ID: JSKN003-005) of the biparatopic HER2-targeting 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 among the most common malignancies worldwide. China has a high incidence of CRC, with over 500,000 new cases diagnosed annually. Approximately 83% of patients are initially diagnosed at an advanced stage, and about 44% already have distant metastases to organs such as the liver or lungs. Despite advances in systemic therapies, the 5-year survival rate for patients with metastatic CRC remains below 20%, indicating a poor prognosis. There are currently no HER2-targeted therapies approved in China for CRC. For patients with HER2-positive advanced CRC who have failed prior treatments with oxaliplatin, fluorouracil and irinotecan, the median progression-free survival (mPFS) of approved therapies 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 within this patient population. Early clinical data of JSKN003 are promising, and JSKN003 has been granted Breakthrough Therapy Designation by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) for this indication. According to the data presented at the 2025 European Society for Medical Oncology (ESMO) Congress, JSKN003 demonstrated an objective response rate (ORR) of 68.8% and a 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 versus investigator's choice of regimen (regorafenib/fruquintinib/trifluridine tipiracil) in HER2-positive advanced CRC patients who have failed prior oxaliplatin, fluorouracil, and irinotecan therapy. 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 endpoints evaluated by BICR/investigator according to RECIST v1.1. The rapid progression of this study marks a critical stage in the development of JSKN003 for colorectal cancer, and is expected to provide patients with a new therapeutic option.

About JSKN003

JSKN003 is developed by site-specific conjugation to 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 release topoisomerase I inhibitors through cellular endocytosis, exerting anti-tumor effects.

Compared to similar ADCs, JSKN003 demonstrates better serum stability, reduced hematological toxicity, and stronger tumor inhibition and bystander effect, resulting in significantly wider therapeutic window.

Multiple registrational studies of JSKN003 are ongoing, including trials in HER2-positive breast cancer (BC), all-comer platinum-resistant ovarian cancer (PROC), HER2-low BC, and HER2-positive colorectal cancer (CRC).

JSKN003 has been granted Orphan Drug Designation (ODD) by the U.S. Food and Drug Administration (FDA) for gastric cancer (GC) and gastroesophageal junction cancer (GEJ), has been granted Fast Track Designation (FTD) by the FDA for the treatment of advanced or metastatic platinum-resistant recurrent epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer (PROC), not restricted by HER2 expression, has been granted Breakthrough Therapy Designation (BTD) by the FDA for the treatment of patients with HER2-expressing PROC who have received prior treatment with bevacizumab. It has also been granted two BTDs by the National Medical Products Administration (NMPA) for PROC and HER2-positive advanced CRC that has failed prior oxaliplatin, fluorouracil, and irinotecan therapy.

In September 2024, the Company entered 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 was granted the 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 conjugation, linker-payloads, dual-payload ADCs, and high-concentration subcutaneous formulations, the Company has built a differentiated and globally competitive pipeline, covering cutting-edge candidates in ADCs, bispecific antibodies, and single-domain antibodies.

One product has received market approval: Envafolimab (KN035, brand name: 恩维达^®), the world's first subcutaneously injected PD-(L)1 inhibitor, offering 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 advancing rapidly. The Company has established strategic partnerships with organizations including CSPC, ArriVent, and Glenmark, covering 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 the development of effective, safe, and globally competitive anti-tumor drugs, delivering China-innovated cancer therapies to benefit patients worldwide.

Source: Alphamab Oncology Related Stocks: HongKong:9966