ZBIO Tanks Despite Positive Data From Rare Autoimmune Diseases Study

Core Insights - Zenas BioPharma's phase III INDIGO study for obexelimab in treating IgG4-related disease has met its primary endpoint, showing a significant reduction in flare risk [1][2][7] Study Results - Obexelimab demonstrated a 56% reduction in the risk of IgG4-RD flare compared to placebo over a 52-week period, achieving the primary endpoint of the INDIGO study [2][7] - The treatment also showed significant efficacy across four key secondary endpoints, including reductions in investigator-assessed flares and the number of flares requiring rescue therapy [3][7] Market Reaction - Despite the positive study results, Zenas BioPharma's shares fell by 51.9% on January 5, indicating that the efficacy data may not have met investor expectations [4][7] Future Plans - The company plans to submit a biologics license application to the FDA for obexelimab in Q2 2026 and a marketing authorization application to the European Medicines Agency in the second half of 2026 [5][7] Ongoing Development - Zenas BioPharma is also exploring obexelimab for other autoimmune diseases, with ongoing studies for systemic lupus erythematosus and multiple sclerosis [8][9] - The company is focused on the successful development of obexelimab and other pipeline candidates, as it currently lacks a marketed product [10] Stock Performance - Over the past six months, Zenas BioPharma's shares have increased by 69.7%, outperforming the industry average rise of 21.5% [6]