Suzhou, China, July 14, 2026 - Alphamab Oncology (stock code: 9966.HK) today announced that HER2 bispecific antibody Anbenitamab (brand name: 恩尼妥® , KN026), 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 granted Breakthrough Therapy Designation (BTD) by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) for the first-line treatment of adult patients with unresectable or metastatic HER2-positive breast cancer, in combination with CSPC’s Docetaxel for Injection (Albumin-bound) (HB1801). This is the second BTD for Anbenitamab, following its prior designation in HER2-positive gastric cancer (including gastroesophageal junction adenocarcinoma), further validating its exceptional clinical value and broad therapeutic potential across HER2-positive solid tumors.
Anbenitamab features a unique mechanism of action, simultaneously binding to two non-overlapping epitopes of HER2 to achieve dual blockade of downstream proliferative signaling pathways and deliver potent synergistic antitumor activity. In May 2026, Anbenitamab obtained approval for marketing from NMPA for gastric cancer indication, becoming the first domestically developed HER2 bispecific antibody commercialized in China, representing a key breakthrough for homegrown innovation in the bispecific antibody field.
Breast cancer ranks among the most common malignant tumors in Chinese women, with the HER2-positive subtype accounting for approximately 20% to 30% of cases. Approximately 20% of patients are already at an advanced stage upon initial diagnosis, and approximately 10% of patients with early-stage HER2-positive breast cancer experience disease recurrence within three years after radical surgery. Although the THP regimen (trastuzumab in combination with pertuzumab and docetaxel) has significantly prolonged progression-free survival (PFS) in such patients, approximately 50% of patients still experience disease progression within two years. Extending PFS and improving long-term prognosis remain key clinical priorities. As the largest therapeutic area for HER2-targeted therapies, the clinical demand in breast cancer, coupled with additional needs in gastric and other cancers, continues to drive the global expansion of the HER2-targeted therapeutics market. Industry estimates project that the global market will exceed US$30 billion by 2035, with China's homegrown innovative therapies poised to become the core driver of market growth.
The pivotal Phase III clinical trial (KN026-003) evaluating Anbenitamab in combination with HB1801 as first-line treatment for HER2-positive advanced breast cancer successfully met its primary endpoint as assessed by the Independent Data Monitoring Committee (IDMC) in June 2026. Results demonstrated that the combination therapy achieved superior PFS compared with the current standard THP regimen, with statistically significant superiority and clear clinical benefit, and showed a trend toward overall survival (OS) benefit. Although trastuzumab deruxtecan plus pertuzumab has shown success in first‑line HER2‑positive advanced breast cancer, it carries a risk of severe interstitial lung disease (ILD). Anbenitamab avoids the ILD risk inherent to ADC therapies and offers a more favorable overall safety profile, making it more suitable for long‑term treatment, especially during the maintenance phase after combination chemotherapy. In addition, the non-ADC antibody regimen in the first‑line setting preserves the opportunity for subsequent ADC therapy, enabling a “first‑line bispecific antibody, second‑line ADC” sequencing strategy to maximize patients’ high-quality overall survival. Detailed data from the study will be presented at an upcoming international academic conference, and a New Drug Application (NDA) for this indication is planned for submission in the near future.
This Breakthrough Therapy Designation will accelerate the clinical development and regulatory review and approval of Anbenitamab in advanced breast cancer. Following the commercialization of the gastric cancer indication, the rapid advancement of the breast cancer indication is expected to fully unlock the clinical value and commercial potential of Anbenitamab, driving sustained product growth. Looking ahead, Alphamab Oncology remains committed to deepening its presence in precision HER2 therapy, strengthening its industry leadership in HER2-targeted treatments, and contributing to the upgrading and high-quality development of China's innovative biopharmaceutical industry.
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 New Drug Application (NDA) will be submitted in the near future. 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. HB1801 has been granted Breakthrough Therapy Designation by NMPA for first-line treatment of patients with unresectable or metastatic HER2-positive 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, 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.
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