Qilu Pharmaceutical Initiates Phase Ib Clinical Trial of GPRC5D/BCMA/CD3 Trispecific Antibody QLS4131 in Systemic Lupus Erythematosus

▎Armstrong

On June 3, 2025, Qilu Pharmaceutical registered a Phase 1b clinical trial for QLS4131 in the treatment of systemic lupus erythematosus on the Clinicaltrials.gov website.

QLS4131 is a GPRC5D/BCMA/CD3 trispecific antibody developed by Qilu Pharmaceutical, with the molecular design shown in the figure below.

This Phase 1b clinical trial registration plans to enroll 108 patients with systemic lupus erythematosus and is expected to be completed by December 2026.

Summary

In China, four GPRC5D/BCMA/CD3 trispecific antibodies have entered the clinical stage, namely MBS314 from Tian Guangshi/Kang Yuan Bochuang, SIM0500 from Mr. Pharmaceutical, QLS4131 from Qilu Pharmaceutical, and IBI3003 from Innovent Biologics. As the potential of B-cell depleting TCE in autoimmune diseases gains popularity across the industry, Qilu Pharmaceutical has taken the lead in shifting to autoimmune indications and advancing into the clinical stage.