SunRock Biopharma and Escugen Forge Alliance to Develop First-in-Class CCR9-Targeted ADC

SunRock Biopharma and Escugen have joined forces in a strategic partnership to co-develop SRB123, a First-in-Class antibody-drug conjugate (ADC) targeting C-C motif chemokine receptor 9 (CCR9), a tumor-associated antigen overexpressed in multiple solid tumors, including pancreatic, ovarian and lung cancer.

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The collaboration combines SunRock’s proprietary SRB1 antibody, selected for its high binding affinity and efficient tumor cell internalization, with Escugen’s EZWi-Fit™ linker-payload platform, a next-generation ADC technology optimized for the linker stability and selective tumor release of the potent payload. The result is a highly differentiated therapeutic candidate designed exclusively for solid tumors with high CCR9 expression and internalization rates.

Under the agreement, both companies will share development responsibilities, file joint patents, and hold reciprocal licensing option rights. The primary goal is to generate robust preclinical proof-of-concept data to support early clinical entry in the near term.

“Combining our deep antibody engineering expertise with Escugen’s innovative conjugation platform enables us to deliver a precision oncology candidate with First-in-Class potential,” said Dr. Laureano Simón, CEO of SunRock. “CCR9 remains an underexploited but clinically validated target. This program addresses real unmet needs in aggressive tumors with poor prognosis.”

Dr. Qing Zhou, Co-Founder and CEO of Escugen, stated, “This strategic collaboration with SunRock Biopharma aligns with our vision of developing First-in-Class precision oncology candidates through technological innovation. It further highlights the unique advantages of our EZWi-Fit™ platform technology in next-generation ADC development. The platform’s strong anti-tumor activity and favorable tolerability provide a solid foundation for targeting high CCR9-expressing solid tumors. We are confident that combining our expertise will accelerate SRB123’s progress and bring new hope to patients.”

CCR9 has been associated with metastatic potential and chemoresistance, particularly in pancreatic and ovarian cancers. SRB1, the unconjugated antibody from SunRock, has already demonstrated strong preclinical efficacy in these models. The ADC format (SRB123) leverages this targeting while enhancing tumor cell killing via Escugen’s payload delivery system.

The partnership will be showcased during the BIO International Convention 2025, where both companies will engage with potential development and commercialization partners.

About SunRock Biopharma

SunRock Biopharma is a biotech company focused on developing next-generation antibody-based therapies targeting unmet medical needs in oncology and immunology. Operating under an open innovation model, SunRock combines cutting-edge academic science, advanced technology platforms, and a selective business approach to generate highly differentiated, licensable assets. Its portfolio includes optimized monoclonal antibodies, next-generation ADCs, and radioconjugates, with validated targets such as CCR9 and HER3. SunRock follows an early-stage out-licensing strategy, designed to maximize risk-adjusted returns, and maintains active collaborations with leading pharma and biotech partners worldwide.

About Escugen

Escugen is a clinical-stage biotechnology company located in Shanghai, China, focusing on the development of innovative ADC drugs. Currently, Escugen's lead Trop-2 ADC pipeline, ESG401, has entered Phase III clinical trials. Escugen's next-generation linker-payload technology platform, EZWi-Fit®, offers significant competitive advantages in terms of safety, efficacy, anti-multiple drug resistance, and pharmacokinetic characteristics. Leveraging this platform technology, Escugen is rapidly expanding its ADC pipeline targeting new or validated target. The first ADC product baring the EZWi-Fit® technology has successfully launched its FIH clinical campaign. In addition, Escugen has licensed this platform technology to several domestic and international biotechnology companies to empower their innovative ADC projects.

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