Samsung Bioepis Presents Nonclinical Data for its First Novel Antibody-Drug Conjugate Candidate SBE303 at AACR 2026

- Nonclinical findings from pharmacology, pharmacokinetics, and toxicology studies support the advancement of SBE303 into clinical development with a favorable therapeutic index (TI), with its first-in-human Phase I clinical trial began in March this year
- SBE303, designed to enhance internalization, demonstrated a wider therapeutic window compared to existing Nectin-4 targeting ADCs, characterized by highest non-severely toxic dose (HNSTD), and an intestinal lung diseases (ILD)-free safety profile of ≥40 mg/kg in repeat-dose toxicity studies and robust efficacy

INCHEON, Korea--(BUSINESS WIRE)--Samsung Bioepis Co., Ltd. announced today that the company has presented a nonclinical characterization of its first novel antibody-drug conjugate (ADC) candidate SBE303 in a poster presentation at the 2026 American Association for Cancer Research (AACR) Annual Meeting, taking place April 17-22, 2026, in San Diego.

“The results we’ve shared reinforce the strong potential of SBE303 as a next-generation ADC and our commitment to innovation beyond biosimilars,” said Donghoon Shin, Executive Vice President and Clinical Sciences Division Leader at Samsung Bioepis. “The nonclinical results show encouraging efficacy, safety, tolerability and a promising ability to work in combination with existing immuno-oncology therapies. Importantly, it demonstrates that our engineered antibody is designed to significantly improve target-mediated internalization. We look forward to continuing the clinical development of SBE303 and advancing our broader mission to bring innovative treatments to patients in need.”

SBE303 is Samsung Bioepis’s first novel ADC engineered to bind to Nectin-4, an adhesion protein that is specifically expressed in tumor cells, including urothelial cancer, lung cancer, and breast cancer.¹ Currently available Nectin-4 targeting ADCs are often limited by narrow therapeutic index (TI) and dose-limiting toxicities. SBE303 is engineered to improve the therapeutic window by combining a highly specific anti-Nectin-4 antibody conjugated with a potent novel topoisomerase I inhibitor via a proprietary linker. For nonclinical characterization of SBE303, a comprehensive set of pharmacology, pharmacokinetics, and toxicology studies was performed to evaluate the underlying mechanism, preclinical efficacy and safety, as well as its potential form combination therapy with anti-PD-1 blockade to support clinical development. SBE303 treatment resulted in robust anti-tumor activity with a differentiated tolerability profile, supporting an improved TI. Notably, the highest non severely toxic dose (HNSTD) was estimated to be 40 mg/kg and no intestinal lung disease (ILD) findings were observed at doses ≥40 mg/kg in repeat-dose toxicity studies. Based on the promising data, SBE303 is currently under Phase I clinical development (NCT07524348).

Poster presentation details:

- Title: Nonclinical characterization of SBE303: A Nectin-4 targeted antibody-drug conjugate (ADC) with novel topoisomerase 1 inhibitor shows a favorable safety margin
- Authors: Ji Yeon Kim, Sungwoo Hyung, Hyun-Ji Choi, Songhyun Lim, Jae Hee Lee, Seokuee Kim, Donghyun Kim, So-Shin Ahn, Donghoon Shin
- Abstract number: 1815
- Presentation Date & Time: Monday, April 20, 2026, 09:00 a.m. CET

The abstract is available on the AACR 2026 website.

About Samsung Bioepis Co., Ltd.

Established in 2012, Samsung Bioepis is a biopharmaceutical company committed to realizing healthcare that is accessible to everyone. Through innovations in product development and a firm commitment to quality, Samsung Bioepis aims to become the world's leading biopharmaceutical company. As a wholly owned subsidiary of Samsung Epis Holdings, Samsung Bioepis continues to advance a broad pipeline of biologic candidates that cover a spectrum of therapeutic areas, including immunology, oncology, ophthalmology, hematology, nephrology, endocrinology. For more information, please visit www.samsungbioepis.com and follow us on LinkedIn and X.

¹ Li K, Zhou Y, Zang M, Jin X, Li X. Therapeutic prospects of nectin-4 in cancer: applications and value. Front Oncol. 2024 Mar 28;14:1354543. doi: 10.3389/fonc.2024.1354543. PMID: 38606099; PMCID: PMC11007101.