Suzhou, China, August 19, 2026 – Alphamab Oncology (stock code: 9966.HK) today announced that the New Drug Application (NDA) for the third indication of Anbenitamab (brand name: 恩尼妥®, KN026), a HER2 bispecific antibody 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), has been accepted by China’s National Medical Products Administration (NMPA) and included in the priority review and approval procedure. The submitted indication is for the first‑line treatment of unresectable or metastatic HER2‑positive adult breast cancer in combination with docetaxel (albumin‑bound) (HB1801). This combination therapy had previously been granted Breakthrough Therapy Designation by Center for Drug Evaluation (CDE).
Anbenitamab is the first domestically developed HER2 bispecific antibody approved for marketing in China. Independently developed using Alphamab Oncology’s proprietary CRIB (Charge Repulsion Induced Bispecific) platform, it can simultaneously and precisely bind to two non-overlapping epitopes of the HER2 receptor (domain IV and domain II), achieving comprehensive blockade of downstream signaling pathways, enhanced HER2 endocytosis, downregulation of HER2 expression, and retained Fc‑mediated ADCC activity. It represents a landmark innovation in the HER2-targeted field.
The NDA is primarily supported by a pivotal phase III clinical study (study code: KN026-003/Healer). As assessed by the Independent Data Monitoring Committee (IDMC) in June 2026, the study successfully met its primary endpoint. Results showed that the progression-free survival (“PFS”) of the combination therapy of Anbenitamab and HB1801 was significantly superior to the current standard therapy of trastuzumab in combination with pertuzumab and docetaxel (the “THP regimen”), with statistically significant superiority and clear clinical benefit, as well as a favorable trend in overall survival (OS). The combination also demonstrated a favorable overall safety profile, making it more suitable for long‑term treatment. Detailed data from the study will be presented at an upcoming international academic conference.
There remains a significant unmet medical need in HER2‑positive advanced breast cancer. In China, approximately 20% of patients with breast cancer are already at an advanced stage upon initial diagnosis, and approximately 10% of patients with HER2-positive early breast cancer experience disease recurrence within three years after radical surgery. Although the THP regimen remains the preferred first-line treatment for HER2-positive advanced breast cancer in China and globally, approximately 50% of patients still experience disease progression within two years, limiting long‑term survival benefits. The KN026‑003/Healer study is the world’s first head‑to‑head trial in HER2‑positive advanced breast cancer to demonstrate that a HER2 bispecific antibody‑based combination therapy can surpass the THP regimen, achieving a historic breakthrough in the first‑line treatment of this indication. It is expected to provide a new treatment option for Chinese patients and reshape the first‑line standard of care.
The combination therapy of Anbenitamab and HB1801 has completed a full-course clinical development program covering neoadjuvant, adjuvant and first-line treatment of advanced HER2-positive breast cancer. The NDA for this combination therapy as neoadjuvant treatment for adult patients with early or locally advanced HER2-positive breast cancer has also been accepted by the NMPA and included in the priority review and approval procedure.
About 恩尼妥® (Anbenitamab Injection)
恩尼妥® (Anbenitamab injection, KN026) is an anti-HER2 bispecific antibody independently developed by the Company using the proprietary Fc-based heterodimer bispecific platform technology called CRIB (Charge Repulsion Induced Bispecific). Anbenitamab can simultaneously bind two non-overlapping epitopes of HER2, resulting in HER2 signal blockade. Through antibody-induced receptor clustering, it enhances antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) effects while promoting the down-regulation of HER2 receptors on the cell surface.
In May 2026, 恩尼妥® obtained approval for marketing from the National Medical Products Administration of China (NMPA) through the priority review and approval pathway for combination with chemotherapy for the treatment of adult patients with locally advanced or metastatic HER2 positive gastric cancer/gastroesophageal junction cancer (GC/GEJ) who have previously received at least one trastuzumab-containing regimen. Two Phase III clinical studies of neoadjuvant treatment for HER2-positive breast cancer (BC) and first-line treatment of HER2-positive BC have reached the primary endpoints, and both corresponding New Drug Applications (NDAs) have been accepted by NMPA. Currently, multiple registrational clinical trials of Anbenitamab for indications such as adjuvant treatment of HER2-positive BC and first-line treatment of HER2-positive GC/GEJ are ongoing.
Anbenitamab has been granted Orphan Drug Designation by the U.S. Food and Drug Administration (FDA) for the treatment of HER2-positive or low expressing GC; it has been granted two Breakthrough Therapy Designations by NMPA for the treatment of patients with HER2-positive GC/GEJ who have failed first-line standard treatment, and first-line treatment of patients with unresectable or metastatic HER2-positive BC.
In August 2021, the Company entered an agreement with JMT-Bio Technology Co., Ltd. (JMT-Bio), a wholly-owned subsidiary of CSPC Pharmaceutical Group Co., Ltd. (CSPC) (stock code: 1093.HK), for the development and commercialization of KN026 in Mainland China. JMT-Bio was granted exclusive license rights of KN026 for the development and commercialization in the indications of BC and GC/GEJ in Mainland China (excluding Hong Kong, Macau and Taiwan).
About Docetaxel (Albumin-bounded) HB1801
Docetaxel (Albumin-Bound) for Injection (HB1801) is one of the flagship drugs independently developed by CSPC Group on its proprietary nanomedicine technology platform. With docetaxel encapsulated in human serum albumin and free of Tween-80 and ethanol, HB1801 has the following advantages over conventional docetaxel injection: (1) Safety: No steroid premedication is needed. It can be rapidly administered at high concentrations, featuring superior safety and better patient compliance; (2) Efficacy: It has exhibited remarkable efficacy in multiple preclinical tumor models and several early-stage clinical studies. Higher doses can be applied clinically to further improve therapeutic outcomes. HB1801 has currently entered pivotal phase III registrational clinical trials for indications including breast cancer and gastric cancer. The two NDAs for HB1801 as neoadjuvant treatment for HER2-positive breast cancer and as first-line treatment for HER2-positive breast cancer have been accepted by the NMPA. In addition, HB1801 has been granted Breakthrough Therapy Designation by the NMPA for the first-line unresectable or metastatic HER2-positve breast cancer.
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.
Two products have 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; and Anbenitamab (KN026, brand name: 恩尼妥®), the first domestically developed HER2 bispecific antibody approved for marketing in China, redefining the standard of treatment for second‑line HER2‑positive gastric cancer. Six bispecific ADC and dual-payload ADC candidates are currently in clinical development, and next-generation ADC pipelines are advancing rapidly. The Company has established strategic partnerships with organizations including CSPC, ArriVent, Glenmark, and Pathos, 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.
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