Anbenitamab

Suzhou, China, October 28, 2025 - Alphamab Oncology (stock code: 9966.HK) announced that the biparatopic HER2-targeting antibody-drug conjugate (ADC) JSKN003 has been granted Fast Track Designation (FTD) by the U.S. Food and Drug Administration (FDA) for the treatment of advanced or metastatic platinum-resistant recurrent epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer (PROC), not restricted by HER2 expression. This marks another accelerated review recognition for JSKN003 from an internationally authoritative regulatory agency, following two previous Breakthrough Therapy Designations from the National Medical Products Administration (NMPA) for both PROC and colorectal cancer (CRC) and an Orphan Drug Designation from the FDA for gastric cancer/gastroesophageal junction cancer (GC/GEJ) this year. As a significant milestone in its global development progress, this achievement fully validates the drug's substantial clinical potential and market prospects. Ovarian cancer (OC) is one of the most common malignant tumors of the female reproductive system. Most patients are diagnosed at an advanced stage, and the disease is characterized by a high recurrence rate and significant treatment challenges. 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 80% of OC cases recur, and eventually progress to PROC, leaving patients with limited effective treatment options and poor prognosis. The U.S. National Comprehensive Cancer Network (NCCN) recommended single-agent non-platinum chemotherapy with or without bevacizumab as preferred regimens for PROC. However, these non-platinum chemotherapies demonstrate limited efficacy, with the objective response rate (ORR) of only 10% to 15%, a median progression-free survival (mPFS) of only 3 to 4 months, and a median overall survival (OS) of approximately 12 months, highlighting an urgent need for new treatment options. The grant of FTD is based on the promising clinical data of JSKN003. The Company has presented a pooled analysis of the phase I clinical study in Australia (JSKN003-101, NCT05494918) and the phase I/II clinical study in China (JSKN003-102, NCT05744427) at the 2025 Annual Meeting of the American Society of Clinical Oncology (ASCO). As of February 28, 2025, 46 patients with PROC, including 21 patients (45.7%) with HER2 IHC 0 and 18 patients (39.1%) with HER2 IHC 1+, 2+, 3+, were enrolled. Among all 46 patients, the ORR was 63.0%, the median PFS was 7.7 months. In patients with HER2 IHC 1+, 2+ and 3+, the ORR was 72.2%, the median PFS was 9.4 months. JSKN003 demonstrated robust PFS improvement in PROC, and the efficacy was observed across different HER2 expression subgroups. The Phase III clinical study of JSKN003 for PROC is currently underway in China, while a Phase II study has been approved to initiate in the U.S. The granting of FTD by the FDA will further accelerate the clinical development and regulatory review process of JSKN003, offering new hope to global patients with PROC who face limited treatment options. About JSKN003 JSKN003 is developed by site-specific conjugation to the Fc glycans of anbenitamab, resulting in a homogeneous and stable ADC with a DAR of 4. JSKN003 binds to two HER2 epitopes on tumor cells and release topoisomerase I inhibitors through cellular endocytosis, exerting anti-tumor effects. Compared to similar ADCs, JSKN003 demonstrates better serum stability, reduced hematological toxicity, and stronger tumor inhibition and bystander effect, resulting in significantly wider therapeutic window. Multiple registrational studies of JSKN003 are ongoing, including trials in HER2-positive breast cancer (BC), all-comer platinum-resistant ovarian cancer (PROC), HER2-low BC, and HER2-positive colorectal cancer (CRC). JSKN003 has been granted Orphan Drug Designation (ODD) by the U.S. Food and Drug Administration (FDA) for gastric cancer (GC) and gastroesophageal junction cancer (GEJ); It has been granted two Breakthrough Therapy Designations by the National Medical Products Administration (NMPA) for platinum-resistant recurrent epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer and HER2-positive advanced CRC that has failed prior oxaliplatin, fluorouracil, and irinotecan therapy. 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). JMT-Bio was granted the exclusive license and sublicense rights to develop, sell, offer for sale and commercialize JSKN003, for tumor-related indications in mainland China (excluding Hong Kong, Macau or Taiwan). Alphamab retains exclusive production rights for JSKN003. About Alphamab Oncology Alphamab Oncology is an innovative biopharmaceutical company focused on oncology. On December 12, 2019, the Company was successfully listed on the Main Board of the Hong Kong Stock Exchange (Stock Code: 9966.HK). 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. Four 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, delivering China-innovated cancer therapies to benefit patients worldwide. Alphamab Oncology Forward-Looking Statements This press release contains statements related to our future business，financial performance and future events involving Alphamab Oncology that may constitute forward-looking statements. These statements include projections and estimates and relevant assumptions, statements regarding plans and expectations and statements regarding future activities, operations and performance. These statements may be identified by words such as "expect," "look forward to," "anticipate" "intend," "plan," "believe," "seek," "estimate," "will," or words of similar meaning. Such statements are based on the certain assumptions of Alphamab Oncology’s management and business operations, which are subject to various risks and uncertainties, including but not limited to political, economic, legal and business environment. The actual results, performance or achievements of Alphamab Oncology may (negatively or positively) vary materially from those described explicitly or implicitly in the relevant forward-looking statements. Unless otherwise required by applicable laws, Alphamab Oncology does not undertake obligation to publicly update any forward-looking statement nor liability for the failure to materialize such forward-looking statements, whether because of new information, future events or otherwise. Pharmaceutical Information Statements Alphamab Oncology does not recommend the clinical use of any already approved or under-development drugs/indications. Any information contained in this press release should not be regarded as any drug application, promotion or advertisement. Source: Alphamab Oncology

Paris-based Sanofi and Houston-based The University of Texas MD Anderson Cancer Center entered a five-year strategic partnership to develop immune therapies and targeted cancer treatments. Paris-based Sanofi and Houston-based The University of Texas MD Anderson Cancer Center entered a five-year strategic partnership to develop immune therapies and targeted cancer treatments. It will leverage MD Anderson’s clinical trials infrastructure and Sanofi’s cancer pipeline. This is yet another example of Sanofi’s increased investment in the cancer space. On July 8, Sanofi licensed a previously undisclosed K-NK0004 program from The Netherlands-based Kiadis Pharma in a deal just shy of $1 billion. The deal covered Kiadis’ proprietary CD38 knock out (CD38KO) K-NK therapeutics for combination with anti-CD38 monoclonal antibodies. In early June, Sanofi (China) Investment Co. signed a collaboration deal with Alphamab Oncology, based in Suzhou, China, to advance clinical trials of Alphamab’s KN-26 with Sanofi’s Taxotere (docetaxel) in HER2+ breast cancer. Jiangsu Alphamab Biopharmaceuticals Co., a wholly owned subsidiary of Alphamab Oncology, made the deal to advance clinical trials of the combination of KN026, an anti-HER2 bispecific antibody, and Sanofi’s Taxotere in HER2+ breast cancer. “Our goal is to improve the outcome for patients with a range of difficult-to-treat cancers, which is best achieved through a deep understanding of how investigational new drugs work,” said Peter Adamson, Global Development Head, Oncology and Pediatric Innovation at Sanofi. “This alliance leverages MD Anderson’s agile approach to early phase clinical trials, their laboratory capabilities and broad scientific expertise.” He added, “This will get us to go/no-go decisions much faster and help us identify potential new combinations and indications more accurately. That will save precious time and help us expand the spectrum of patients who could potentially benefit from our therapies.” MD Anderson oversees one of the largest cancer clinical trial programs in the U.S., which includes platforms for tissue collection, molecular and immune profiling and data analysis. This allows for full coverage of clinical trials from the time cancer biopsies are made, through and after treatment. “Not only do clinical trials help us to advance life-saving new treatments for our patients in need, they provide us with valuable information to understand which therapies may be more effective for which patients,” said Funda Meric-Bernstam, chair of Investigational Cancer Therapeutics at MD Anderson. “We are pleased to collaborate with Sanofi in this effort to accelerate the development of a pipeline of innovative cancer therapies.” The pact will also offer support of clinical trials for extra indications and drug combinations that are already being conducted at MD Anderson. The two organizations will collaboration on trial design, as well as usage of biomarker tests and assays. The partnership is expected to launch its first studies together this summer. “MD Anderson’s expertise in deep immune phenotyping and molecular profiling will provide invaluable insights into our emerging immunotherapy assets, helping us refine our selection of indications and explore new avenues,” said Dmitri Wiederschain, Global Head of Immuno-Oncology Research at Sanofi. “The knowledge we gain in this collaboration will also deepen our shared understanding of cancers’ potential vulnerabilities.” In early June, Sanofi’s chief executive officer, Paul Hudson, presented an overview of the company’s oncology strategy. Its strategy is focused on four core therapeutic areas in cancer, including multiple myeloma, skin, lung, and breast cancers. He indicated that its four anchor oncology therapies include Sarclisa, an anti-CD38 monoclonal antibody and Libtayo (cemiplimab-nwlc), a PD-1 checkpoint inhibitor, and pipeline programs that include an investigational anti-CEACAM 5 antibody drug conjugate and SERD (‘859), an oral selective estrogen receptor degrader. “We are rapidly building momentum with the execution of our oncology strategy, with several developments on both our pipeline and marketed treatments,” said Hudson. “Additionally, we are assembling a world-class development and marketing team to support our growth in this core area. We believe our efforts and treatments have the potential to make a significant difference in the lives of people living with cancer.”