Zenas BioPharma Partner InnoCare Achieves Phase 2b Success For Orelabrutinib In Lupus, Wins Approval To Start Phase 3 Trial In China

Zenas BioPharma, Inc., a Nasdaq-listed clinical-stage global biopharmaceutical company focused on developing and commercializing transformative therapies for patients with autoimmune diseases, announced that its partner InnoCare Pharma has achieved a key clinical milestone in the development of orelabrutinib for systemic lupus erythematosus (SLE). InnoCare reported that the drug met its primary endpoint in a Phase 2b clinical study in patients with SLE and has also received approval from China’s Center for Drug Evaluation to initiate a Phase 3 registrational clinical trial as part of its development program in China.

The Phase 2b study enrolled a total of 187 patients with SLE, who were randomized in a 1:1:1 ratio to receive either orelabrutinib 75 mg once daily, orelabrutinib 50 mg once daily, or placebo. The primary endpoint of the trial was the SLE Response Index-4 (SRI-4) response rate at week 48. Results showed that patients treated with orelabrutinib 75 mg once daily achieved a statistically significant improvement in SRI-4 response compared with placebo, with response rates of 57.1 percent versus 34.4 percent, respectively. The study therefore met its primary endpoint, and a clear dose-dependent trend was observed, with the higher dose demonstrating greater efficacy than the 50 mg once-daily dose.

In addition to the primary endpoint, orelabrutinib demonstrated positive results across key secondary endpoints. At week 48, patients in the 75 mg once-daily group showed significantly higher response rates based on both the SLE Response Index-6 (SRI-6) and the British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) compared with placebo. These results further support the clinical activity of orelabrutinib in SLE and highlight its potential as a differentiated therapy in this patient population.

Orelabrutinib was generally well tolerated throughout the study, with a safety profile consistent with its mechanism of action as a Bruton’s tyrosine kinase inhibitor and with the known biology of SLE. No new safety signals were reported. Earlier clinical evidence supporting the drug’s potential in SLE was previously presented from a Phase 2a study, which was featured as a late-breaking oral presentation at the European Congress of Rheumatology in 2022.

Orelabrutinib is a highly selective, central nervous system–penetrant, oral small-molecule BTK inhibitor that is being evaluated across multiple autoimmune and inflammatory conditions. In October 2025, Zenas BioPharma and InnoCare Pharma entered into a transformational licensing agreement that significantly expanded Zenas’ pipeline and global reach. Under the agreement, Zenas obtained exclusive rights to develop, manufacture, and commercialize orelabrutinib globally in the field of multiple sclerosis, as well as in all non-oncology indications outside Greater China and Southeast Asia, while InnoCare retained global oncology rights.

As part of the same agreement, Zenas also acquired exclusive rights outside Greater China and Southeast Asia to develop, manufacture, and commercialize ZB021, an oral IL-17AA/AF inhibitor, and global rights to ZB022, an oral, brain-penetrant TYK2 inhibitor. These assets further strengthen Zenas BioPharma’s position as a global developer of innovative therapies for autoimmune and neuroinflammatory diseases.