Alphamab Oncology Announces IND Application for Innovative EGFR/HER3 Dual Payload Bispecific ADC JSKN021 was Officially Accepted by CDE

SUZHOU, China, March 13, 2026 /PRNewswire/ -- Alphamab Oncology (stock code: 9966.HK) announced that the Investigational New Drug (IND) application for JSKN021, an independently developed innovative dual payload bispecific antibody-drug conjugate (ADC) targeting EGFR and HER3, has been officially accepted by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA). The Company plans to initiate a clinical study of JSKN021 for the treatment of advanced malignant solid tumors.

JSKN021 is a "2-in-1" dual payload bispecific ADC targeting EGFR and HER3. By leveraging glycan-specific conjugation technology, it precisely and quantitatively links two different cytotoxic payloads to the antibody's Fc region. This process has been refined to be simple, stable, and highly efficient. The generated ADC product demonstrates the characteristically high stability and safety profile intrinsic to Alphamab Oncology's proprietary technology platforms. According to preclinical data presented at the 2025 annual meeting of American Association for Cancer Research (AACR), JSKN021 inhibited the growth of cancer cells with either HER3 or EGFR or both expressions. Furthermore, JSKN021 showed stronger tumor inhibition efficacy than mono payload ADCs in multiple CDX models.

This Phase I clinical study will evaluate the safety, tolerability, pharmacokinetics (PK), and antitumor activity of JSKN021 in patients with advanced malignant solid tumors, and determine the maximum tolerated dose (MTD) and/or recommended Phase II dose (RP2D).

ABOUT JSKN021

JSKN021 is a first-in-class dual payload ADC consisting of an EGFR/HER3 bispecific antibody conjugated with novel topoisomerase I inhibitor (T01) and Monomethyl auristatin E (MMAE). Engineered with finely tuned binding avidity in both arms to address tumor heterogeneity while minimizing on-target, off-tumor toxicity, JSKN021 was designed for enhanced stability and improved homogeneity. It combines T01 (drug-to-antibody ratio (DAR) 4) and MMAE (DAR 2) payloads to overcome non-response and resistance observed with single-payload treatment strategies. The investigational new drug (IND) application for JSKN021 has been accepted by the Center for Drug Evaluation (CDE), and the Phase I clinical trial for advanced malignant solid tumors will soon be initiated.

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. Five 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, enabling patients to achieve long-term, high-quality survival and delivering China-innovated cancer therapies to benefit patients worldwide.

SOURCE Alphamab Oncology