Alphamab Oncology Announced Anti-HER2 Bispecific ADC JSKN003 Received Approval from CDE to Initiate a Phase III Clinical Study for Ovarian Cancer

Alphamab Oncology (stock code: 9966.HK) announced that anti-HER2 bispecific antibody-drug conjugate (ADC) JSKN003 has received approval from the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) to initiate a Phase III clinical study (study number: JSKN003-306). The study aims to compare the efficacy of JSKN003 versus investigator-selected chemotherapy for the treatment of platinum-resistant recurrent epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer.

Ovarian cancer (OC) ranks as the third most common gynecologic malignancy in China and continues to show a rising incidence, with the highest mortality rate among all malignant gynecologic tumors. The standard treatment regimens recommended by authoritative guidelines both domestically and internationally include surgery combined with platinum-based chemotherapy and targeted therapy maintenance. However, about 70% of OC cases recur after treatment and progress to platinum-resistant ovarian cancer (PROC), leaving patients with limited effective treatment options and poor prognosis. The 2024 NCCN guideline recommend non-platinum cytotoxic drugs and targeted monotherapy as the preferred treatment option for patients with PROC. Previous studies have shown that the objective response rate (ORR) of PROC treated with non-platinum chemotherapy alone is only 4% to 13%, while the ORR for non-platinum chemotherapy combined with targeted therapy is merely 10% to 30%, highlighting an urgent need for new treatment options.

JSKN003 is an anti-HER2 bispecific ADC, which is developed inhouse with Alphamab's proprietary Glycan-specific conjugation platform. Multiple clinical studies of JSKN003 are currently being conducted in Australia and China. Clinical research results have demonstrated favorable tolerability and safety profile, with promising efficacy of JSKN003 in heavily pretreated patients with advanced solid tumors. Data from two Phase I clinical studies of JSKN003 for the treatment of PROC presented at the 2024 European Society for Medical Oncology (ESMO) Congress indicated that JSKN003 monotherapy showed promising efficacy signals in patients with advanced PROC, and the efficacy was observed across patients with or without HER2 expression, prior bevacizumab treatment, prior PARP inhibitor treatment, and whether they were primary platinum-resistant.

JSKN003-306 is a randomized, open-label, parallel-controlled, multi-center Phase III clinical study for the all-comer population with platinum-resistant recurrent epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer who have received 1-4 lines of prior treatment. The study aims to compare the efficacy and safety of JSKN003 versus investigator-selected chemotherapy in this patient population.

About JSKN003

JSKN003 is an anti-HER2 bispecific antibody-drug conjugate (bis-ADC), which is developed inhouse with Alphamab's proprietary Glycan-specific conjugation platform. JSKN003 can bind HER2 on the surface of tumor cells and release topoisomerase I inhibitors (TOPIi) through cellular endocytosis, thereby exert anti-tumor effects. Compared with its ADC counterparts, JSKN003 demonstrated better serum stability and stronger bystander effect, which effectively expands the therapeutic window.

Multiple clinical studies at various stages of JSKN003 are currently being conducted in China and Australia. Clinical research results have demonstrated favorable tolerability and safety profile, with promising efficacy of JSKN003 in heavily pretreated patients with advanced solid tumors, especially in patients with HER2-expressing breast cancer, platinum-resistant ovarian cancer (PROC) or high HER2-expressing solid tumors.

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), pursuant to which, JMT-Bio was granted the exclusive license and sublicense rights to develop, sell, offer for sale and commercialize JSKN003, for the treatment of tumor-related indications (the "Field") in mainland China (excluding Hong Kong, Macau or Taiwan) (the "Territory") and become the sole marketing authorization holder for JSKN003 for the Field in the Territory. Alphamab retains the sole right to supply JSKN003.

About Alphamab Oncology

Alphamab Oncology is a leading biopharmaceutical company committed to the development, manufacturing, and commercialization of cutting-edge biotherapeutics for the treatment of cancer. On December 12, 2019, the company was successfully listed on the Main Board of the Hong Kong Stock Exchange, trading under the stock code 9966.

Our integrated platform seamlessly combines research, development, and manufacturing capabilities for biologics. We take pride in our extensive intellectual property portfolio, which encompasses protein/antibody engineering, antibody screening, and multi-module/multi-functional antibody modification.

Distinguished by a globally competitive pipeline, Alphamab Oncology specializes in antibody-drug conjugation (ADC), single domain antibody, and bispecific antibodies. Notably, Envafolimab, the world's first subcutaneously injectable PD-L1 inhibitor, was approved by Chinese authorities in 2021, making a significant breakthrough in the convenience and accessibility of cancer treatment. Three assets are currently undergoing Phase III or pivotal clinical trials, and several other bispecific ADC new drug candidates are in early clinical stage. 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 dedicated to the development of safe, effective and affordable drugs, leveraging a global competitive edge.