Junshi Biosciences Completes First Patient Dosing in Phase 3 Trial for JS203

SHANGHAI, China, Oct. 23, 2026 /CourierPR/ -- Junshi Biosciences, a leading innovation-driven biopharmaceutical company based in Shanghai, has announced the completion of the first patient dosing in a phase 3 clinical trial for its product JS203. JS203 is a recombinant humanized anti-CD20/CD3 bispecific antibody, designed to treat relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL).

This clinical trial, known as the JS203-003-III-DLBCL Study (NCT07808827), is the first registrational study for JS203. The trial aims to compare the efficacy and safety of JS203 in combination with chemotherapy against rituximab in combination with chemotherapy for patients with R/R DLBCL. The study, led by Professor Yuqin SONG of Beijing Cancer Hospital, plans to enroll 282 subjects, with overall survival (OS) as the primary endpoint.

Diffuse large B-cell lymphoma (DLBCL) is one of the most common types of non-Hodgkin lymphoma (NHL), accounting for approximately 40% of adult NHL cases in China. According to GLOBOCAN 2022 statistics, there are approximately 45,000 new cases of DLBCL in China each year, with the incidence rate showing a slow increasing trend. DLBCL is characterized by high aggressiveness and rapid progression. A retrospective study in an Asian population revealed that, even after active treatment, patients with R/R DLBCL had a median overall survival (mOS) of over one year and a 5-year survival rate of approximately 30%.

JS203, developed by Junshi Biosciences, consists of an anti-CD20 segment and an anti-CD3 segment. By associating and activating lymphoma cells (binding to CD20) and T cells (binding to CD3), JS203 enables T cells to effectively kill lymphoma cells. Early clinical studies have shown that, for JS203 monotherapy at the recommended phase 2 dose (RP2D) administered with step-up dosing (SUD) to 30 mg for the treatment of patients with CD20-positive relapsed or refractory B-cell non-Hodgkin lymphoma, the objective response rate (ORR) reached 72.4%. Among patients with DLBCL, the ORR was 69.7%, and the complete response rate (CRR) was 39.4%, with persistent relief observed. The overall safety profile was manageable, with a cytokine release syndrome (CRS) incidence rate of only 27.3% and no occurrence of immune effector cell-associated neurotoxicity syndrome (ICANS).

Founded in December 2012, Junshi Biosciences is dedicated to the discovery, development, and commercialization of novel therapies. The company has a well-structured research pipeline, covering therapeutic areas including cancer, autoimmune, metabolic, and infectious diseases. Five of the company's products have received marketing authorizations in China and international markets, including its domestically developed anti-PD-1 monoclonal antibody, toripalimab, which has been approved in over 50 countries and regions, including China, the US, and Europe.

The company currently employs more than 3,000 people worldwide and has a business presence in multiple countries and regions around the world. With a mission to provide patients with world-class, trustworthy, affordable, and innovative drugs, Junshi Biosciences continues to advance its research and development efforts to bring new treatment options to patients.