A Pivotal Phase II/III Clinical Study of Anti-HER2 Bispecific Antibody KN026 Have Met the Primary Endpoint of PFS at Interim Analysis

SUZHOU, China, May 1, 2025 /PRNewswire/ -- Alphamab Oncology (stock code: 9966.HK) and CSPC Pharmaceutical Group Co., Ltd. ("CSPC") (Stock Code: 1093.HK) jointly announced that a phase II/III clinical trial of anti-HER2 bispecific antibody KN026 (Study ID: KN026-001) in combination with chemotherapy as second-line or above treatment of HER2-positive gastric cancer (GC) (including gastroesophageal junction cancer (GEJ)), has completed the first interim analysis and met the pre-specified primary endpoint of progression-free survival (PFS) as evaluated by an Independent Data Monitoring Committee (IDMC), with both statistical significance and clinical relevance.

KN026-001 is a randomized, multicenter, Phase II/III clinical study designed to evaluate the efficacy of KN026 in combination with chemotherapy inpatients with HER2-positive advanced, unresectable, or metastatic GC (including GEJ) who have failed first-line treatment. Part 2 of KN026-001 is a randomized, double-blind, placebo-controlled Phase III study. Patients with HER2-positive GC (including GEJ) who had previously received and failed at least first line standard treatment were enrolled and randomized 1: 1 to receive either KN026 in combination with chemotherapy or placebo in combination with chemotherapy. The primary endpoints of this study are PFS and overall survival (OS) as assessed by the Independent Review Committee (IRC).

The interim PFS analysis results demonstrated that, compared to the current standard treatment, KN026 in combination with chemotherapy significantly improved PFS, reduced the risk of disease progression or death, and showed a trend toward OS benefit. Detailed data from this study will be presented at an upcoming international academic conference.

About KN026

KN026 is an anti-HER2 bispecific antibody independently developed by Alphamab Oncology using the proprietary Fc-based heterodimer bispecific platform technology called CRIB (Charge Repulsion Induced Bispecific). KN026 can simultaneously bind two non-overlapping epitopes of HER2, leading to HER2 signal blockade. KN026 has demonstrated better tumor inhibition in HER2-positive tumor cell lines compared with trastuzumab and pertuzumab in combination. Additionally, KN026 has also shown inhibitory effect on tumor cells with trastuzumab-resistant cell lines.

The results of multiple clinical studies in different stages showed that KN026 has significant anti-tumor activities, even in heavily pretreated patients with HER2-positive breast cancer (BC) and gastric cancer (GC), including those with prior anti-HER2 treatment. Currently, several pivotal clinical trials of KN026 for the second-line and beyond treatment of HER2-positive GC/gastroesophageal junction cancer (GEJ), the first-line treatment of HER2-positive BC, neoadjuvant treatment for HER2-positive BC are being conducted. KN026 in combination with chemotherapy for the treatment of patients with HER2-positive GC (including GEJ) who have failed first-line standard treatment was granted breakthrough therapy designation by the Center for Drug Evaluation (CDE) of the National Medical Products Administration of China (NMPA).

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, pursuant to which, JMT-Bio was granted exclusive license rights of KN026 for the development and commercialization in the indications of BC an GC/GEJ in Mainland China (excluding Hong Kong, Macau and Taiwan).

About Alphamab Oncology

Alphamab Oncology is an innovative biopharmaceutical company focusing on oncology therapeutics. By leveraging its proprietary core technology platforms including single-domain antibodies, bispecific antibodies, glycan-specific conjugation, linker-payload, dual-payload antibody conjugation, and subcutaneous high concentration formulation for biologics, the Company has established a differentiated and globally competitive product portfolio, covering cutting-edge areas such as antibody-drug conjugates (ADCs), bispecific antibodies, and single-domain antibodies.

The Company has one product approved for marketing (Envafolimab, the world's first subcutaneously injectable PD-(L)1 inhibitor), which has made a significant breakthrough in the convenience and accessibility of cancer treatment. Additionally, the Company has multiple bispecific antibodies and bispecific ADCs in clinical stage, while rapidly advancing the preclinical pipeline prioritizing bispecific ADCs and dual-payload ADCs. Multiple strategic collaborations based on innovative products or technology platforms have been established with partners such as CSPC, ArriVent, and Glenmark.

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 to benefit patients.

SOURCE Alphamab Oncology