Biosion Announces First Patient Dosed in Investigator-Initiated Phase 1 Trial of BSI-082, a Next-Generation Anti-SIRPα Monoclonal Antibody for Advanced Solid Tumors

Milestone validates the clinical potential of BSI-082 as a synergistic combination partner for antibody-drug conjugates (ADCs) and reinforces Biosion's "In Global, For Global" collaboration strategy.

NEWARK, Del. and NANJING, China, Feb. 3, 2026 /PRNewswire/ -- Biosion, Inc. ("Biosion"), a global, clinical-stage biotechnology company developing innovative antibody-based therapeutics, today announced that the first patient has been dosed in a Phase 1a/1b Investigator-Initiated Trial (IIT) evaluating BSI-082, a highly differentiated, fully human anti-SIRPα monoclonal antibody. The study is sponsored by and being conducted at the Mays Cancer Center, a National Cancer Institute (NCI)-designated Cancer Center and part of The University of Texas at San Antonio's Health Science Center.

This clinical milestone highlights the medical community's strong interest in Biosion's oncology assets and follows the company's recent transformative partnership with Aclaris Therapeutics for its immunology portfolio.

Collaborating to Unlock Innate Immunity

BSI-082 is engineered to block the CD47-SIRPα "don't eat me" signal, a critical checkpoint tumor cells use to evade macrophage phagocytosis. Unlike other candidates in the class, BSI-082 was designed using Biosion's proprietary H³ Antibody Discovery Platform to overcome historical development challenges.

Key differentiators of BSI-082 include:

• Broad Population Coverage: High-affinity binding to SIRPα variants V1, V2, and V8, covering >90% of the human population.
• Superior Safety Profile: Engineered Fc domain minimizes binding to red blood cells (RBCs) and platelets, significantly reducing the risk of anemia and thrombocytopenia often seen with anti-CD47 therapies.
• Preserved T-Cell Function: No binding to SIRPγ, ensuring that adaptive immune responses remain active and uninhibited.

"The initiation of this trial by a premier institution like the Mays Cancer Center serves as powerful validation of BSI-082's scientific rationale and therapeutic potential," said Mingjiu Chen, Ph.D., Founder and CEO of Biosion. "BSI-082's unique profile—specifically its ability to potently block the 'don't eat me' signal without compromising patient safety—positions it as an ideal combination partner for standard-of-care therapies, particularly antibody-drug conjugates (ADCs). We are honored to support Dr. Sarantopoulos and his team in this study, which represents a key step in our strategy to maximize the value of our oncology assets through high-quality clinical partnerships."

Study Design and Strategic Combinations

The Phase 1a/1b study is an open-label, dose-escalation and dose-expansion trial designed to evaluate the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of BSI-082 in patients with locally advanced or metastatic solid tumors.

• Phase 1a: Will establish the Recommended Dose for Expansion (RDE) of BSI-082 as a monotherapy.
• Phase 1b: Will evaluate BSI-082 in combination with trastuzumab deruxtecan (T-DXd) in patients with HER2-positive solid tumors. Preclinical data has demonstrated that SIRPα blockade can synergistically enhance the antitumor activity of ADCs by promoting antibody-dependent cellular phagocytosis (ADCP).

"Targeting the innate immune system via the SIRPα-CD47 axis offers a compelling therapeutic strategy for refractory tumors," said John Sarantopoulos, M.D., associate professor of medicine in the Division of Hematology and Oncology, medical oncologist, and principal investigator at the Mays Cancer Center. "We are excited to lead the clinical evaluation of BSI-082, whose design addresses key limitations of earlier generation agents. We look forward to exploring its potential to improve outcomes for patients, particularly in combination with ADCs."

About Biosion 

Biosion is a global, clinical-stage biotechnology company dedicated to developing innovative antibody therapies to improve outcomes for patients with immunological and oncological diseases. By leveraging its proprietary core technology platforms—including the H³ Antibody Discovery platform, the SynTracer® HT Endocytosis platform, and the Flexibody® Bispecific platform—the company develops highly differentiated innovative medicines to address significant unmet medical needs worldwide. Through its flexible "Discover-Develop-Partner" model, Biosion has established over 10 global partnerships, with 9 programs currently in clinical development. These include monoclonal antibodies, bispecific antibodies, and antibody-drug conjugates (ADCs). Biosion maintains integrated operations across the United States, China, and Australia. For more information, please visit www.biosion.com.

CONTACT:
PR: Josie Zhou, [email protected]
BD: Anthony Yeh, [email protected]

SOURCE Biosion, Inc.