Zenas BioPharma stock slides again premarket after INDIGO Phase 3 data sparks fresh scrutiny
New York, January 6, 2026, 08:44 EST — Premarket Zenas BioPharma (ZBIO.O) shares were down 5.8% at $15.66 in premarket trading on Tuesday after ending Monday down 51.9% at $16.61. MarketScreener The slide follows a late-stage readout for the company’s lead drug obexelimab in IgG4-related disease (IgG4-RD), a rare immune condition that can inflame and scar organs. Zenas met the main goal, but Wedbush analyst Martin Fan said investors were looking for a stronger effect than the hazard ratio of 0.44, a measure of risk over time where lower is better. Amgen’s Uplizna, the only FDA-approved treatment for IgG4-RD, cut