SUZHOU, China, Nov. 6, 2025 -- The 16th World ADC San Diego, held from November 3–6, 2025, brought together industry leaders in San Diego, USA. Dr. Ting Xu, Founder, Chairman, and CEO of Alphamab Oncology, was invited to deliver a presentation titled "JSKN021: EGFR/HER3 Targeted Dual-payload ADC", showcasing the company's cutting-edge technological breakthroughs and innovative achievements in the ADC field to a global audience. The modularly designed dual-payload ADC platform technology and the prominent preclinical efficacy of JSKN021 garnered attention from attendees, making it one of the most remarkable highlights of Chinese innovation at the event.

Focusing on Clinical Challenges to Build Sustainable, Platform-Driven Advantages

As a pioneering innovator in China's oncology landscape, Alphamab Oncology is continuously dedicated to addressing unmet clinical needs, with a strategic focus on overcoming key ADC challenges, including tissue penetration, off-target toxicity, and tumor heterogeneity, to advance the development of more effective and safer next-generation ADC therapies.

With a decade of dedicated efforts, Alphamab Oncology has independently developed multiple core technology platforms encompassing single-domain antibodies, bispecific antibodies, glycan-specific conjugation, linker-payload, dual-payload conjugation, and high-concentration subcutaneous formulations. These platforms operate synergistically to form a modular and iterative R&D ecosystem for innovative drugs, serving as the core engine that powers the company's continuous development of innovative molecules with global competitiveness.

Dr. Xu's presentation provided an overview of Alphamab Oncology's integrated ADC technology system, with a special focus on the innovative dual-payload conjugation platform. He detailed that the glycan-specific conjugation platform utilizes a proprietary "one-enzyme, two-step" approach to precisely modify Fc glycans, significantly improving the homogeneity and pharmacokinetic stability of ADCs while effectively reducing off-target toxicity. Meanwhile, the linker-payload platform (Alphatecan) employs a hydrophilic linker and a topoisomerase I inhibitor (TOPO1i) payload, specifically designed to optimize both the efficacy and safety profiles of ADC therapeutics. The dual-payload platform, a standout feature of Alphamab Oncology's ADC technology, enables the simultaneous conjugation of two toxin molecules with distinct mechanisms of action onto a single antibody. This approach effectively enhances ADC efficacy and addresses the challenges of tumor heterogeneity and drug resistance.

With Cutting-Edge Technology, Differentiated Pipeline Demonstrating Robust R&D Capabilities

Leveraging its fully integrated proprietary technology platforms, Alphamab Oncology has established a product portfolio with "Best-in-Class" (BIC) or "First-in-Class" (FIC) potential.

In the later sessions of his presentation, Dr. Xu provided an in-depth analysis of the development progress and preclinical data of JSKN021, fully demonstrating its role as a representative example of the company's latest R&D achievements. JSKN021 is a "2-in-1" antibody-drug conjugate targeting both EGFR and HER3, exhibiting excellent patent drug potential. The molecule employs two glycosyltransferases to efficiently catalyze the site-specific and quantitative conjugation of two distinct payloads onto the Fc glycans of the antibody. Through extensive optimization, this process has been refined to be simple, stable, and highly efficient. The generated ADC product demonstrates the characteristically high stability and safety profile intrinsic to Alphamab Oncology's proprietary technology platforms. Across various animal tumor models with different cells, JSKN021 has shown superior inhibitory activity compared to competitive molecules. The company plans to submit an Investigational New Drug (IND) application for JSKN021 by the end of 2025.

Currently, four of the company's bispecific ADC candidates have entered clinical development, spanning key targets including HER2, TROP2, HER3, PD-L1, αvβ6, and EGFR, demonstrating remarkable translational power and pipeline execution efficiency of the proprietary platforms.

• JSKN003 is Alphamab's first ADC developed based on a HER2-targeting bispecific antibody. Utilizing glycan-specific conjugation technology, it achieves a homogeneous drug-to-antibody ratio (DAR) of 4, exhibiting superior serum stability, reduced hematological toxicity, and stronger tumor inhibition and bystander effect compared to similar ADCs. 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 designations including Breakthrough Therapy, Orphan Drug, and Fast Track by both Chinese and U.S. regulatory authorities, with the first New Drug Application (NDA) expected to be submitted in 2026.
• JSKN016 is a TROP2/HER3 targeting bispecific ADC developed using the proprietary single-domain antibody and bispecific antibody platforms. It is conjugated via site-specific glycosylation to generate a homogeneous and stable ADC with a drug-to-antibody ratio (DAR) of 4. JSKN016 has demonstrated promising efficacy across multiple solid tumors and a favorable safety profile with low hematological toxicity.
• JSKN022 is the world's first PD-L1/αvβ6 bispecific ADC to advance into clinical trials. It was precisely constructed through antibody-directed evolution to generate a bispecific single-domain antibody, followed by glycan-specific conjugation. JSKN022 simultaneously blocks the PD-L1/PD-1 pathway and αvβ6-mediated TGFB1/3 production, thereby activating immune responses and improving the tumor immune microenvironment. The Phase I clinical study of JSKN022 has been conducted in China.

Multidimensional Breakthroughs Driving a Leap in ADC Clinical Value

Powered by its integrated, platform-driven innovation engine, Alphamab Oncology is dedicated to exploring new horizons in ADC therapeutics, focused on bringing high-value treatment options to patients globally. As presented by Dr. Xu, the company's R&D efforts are around three key strategic directions:

• Dual Advancements in Efficacy and Safety: Our current focus is novel ADCs with increased safety without compromising efficacy, thereby enabling the application of ADC therapies as the preferred choice in early line and perioperative settings.
• Tackling Heterogeneity and Resistance: We focus on overcoming the challenges of tumor heterogeneity and drug resistance by developing ADC-based therapeutic strategies suitable for chronic diseases management. This approach aims to extend patient survival while optimizing dosing regimens to improve quality of life.
• Multidimensional Exploration of Combination Therapies: We are advancing the combined use of ADC drugs with immunotherapy (IO), tyrosine kinase inhibitors (TKIs), T-cell engagers (TCEs), and standard chemotherapy (such as Decetaxol, Caboplatin, and Paclitaxol) to expand the therapeutic window and build diversified clinical solutions.

Confronting intensifying industry competition, Alphamab Oncology has established four core technological pillars to build differentiated advantages: leveraging the function of the antibody, particularly bispecific ADCs; identifying novel and better payload mechanisms; developing multi-payload ADCs with suitable linkers; and further increasing tumor-specific release of payloads.

These four interconnected and co-evolving pillars collectively form the company's competitive edge in the ADC landscape and point toward the future direction of the industry—shifting from "later-line rescue" to "early-line intervention and chronic disease management", and from monotherapy to combination strategies, ultimately helping patients achieve longer survival and a better quality of life.

Conclusion

Guided by a systematic technology platform and a clear R&D strategy, Alphamab Oncology is accelerating the translation of innovative concepts into clinical value. From the biparatopic design of JSKN003 demonstrating outstanding efficacy, to JSKN016 broadening the therapeutic window with its favorable safety profile; from JSKN022 pioneering a new mode of immune microenvironment modulation, to JSKN021 tackling tumor heterogeneity through a dual-payload strategy—each product embodies the company's deep understanding of clinical needs and its forward-looking approach to technological innovation.

As these innovative molecules advance through clinical stages and the relevant data continue to be read out, the company is not only bringing new hope to cancer patients but also helping steer the entire ADC field toward safer, more effective, and more precise therapeutics. Under the strategic vision of "developing differentiated, clinically valuable and globally competitive new drugs", Alphamab Oncology is demonstrating the robust capabilities of Chinese biopharmaceutical innovation on the global ADC stage, with its platform-driven innovation strength and international development perspective.

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.