Obexelimab: A Differentiated B Cell Therapy - Obexelimab is a potentially highly differentiated I&I franchise molecule targeting autoimmune diseases [5] - It is the first bifunctional B cell targeting (CD19 x FcγRIIb) antibody in Phase 3 trial for IgG4-Related Disease and Phase 2 trials for RMS and SLE [6] - The company estimates a potential multi-billion-dollar commercial opportunity for Obexelimab [6, 45, 120] - Zenas BioPharma had approximately $314 million in cash as of Q1 2025, funding operations into Q4 2026 [6, 121] Clinical Development and Trial Readouts - Phase 3 topline results for the INDIGO trial in IgG4-RD are expected around year-end 2025 [46] - Phase 2 primary endpoint (12-week) data for the MoonStone trial in RMS is expected in early Q4 2025 [46] - Phase 2 primary endpoint (24-week) data for the SunStone trial in SLE is expected in mid-2026 [46] - The Phase 3 INDIGO trial in IgG4-RD has completed enrollment with approximately 190 patients [67] Market Opportunity and Strategic Collaboration - The estimated prevalence of IgG4-RD patients in the U S is approximately 20,000 to 40,000, and approximately 20,000 to 40,000 collectively in the UK, Germany, France, Italy, and Spain alone [52] - The company estimates that Obexelimab represents a compelling $1 billion+ commercial revenue opportunity in the U S alone for IgG4-RD [75] - Bristol Myers Squibb (BMS) has rights to develop and commercialize obexelimab in Japan, South Korea, Taiwan, Singapore, Hong Kong and Australia [47, 110]