New York, January 6, 2026, 08:44 EST — Premarket
- Zenas BioPharma shares fell about 6% in premarket trade after a 52% drop in the prior session.
- Investors weighed Phase 3 INDIGO results for obexelimab in IgG4-related disease against tougher expectations and a rival drug already on the market.
- Wall Street split: Morgan Stanley cut its rating, while Jefferies and H.C. Wainwright kept buy calls with lower targets.
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. 1
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 flare risk 87% in its own study; Zenas CEO Lonnie Moulder told analysts, “I think I’ll go back and point once again, to the almost 60% risk reduction, as opposed to comparing to the Uplizna study.” 2
In an SEC filing, Zenas said obexelimab also met all four key secondary endpoints and showed no new safety signals, with infection rates lower than placebo and similar injection-site reactions. The company said it expects to file a Biologics License Application (BLA) — the FDA’s approval request for biologic drugs — in the second quarter of 2026, and a European Marketing Authorization Application in the second half of 2026. Harvard Medical School professor John Stone said the data suggest the weekly, self-injected drug “may be an important new therapy” for IgG4-RD patients. 3
Morgan Stanley downgraded Zenas to Equal Weight from Overweight and cut its price target to $19 from $37, saying the results fell short of the benchmark set by Uplizna and could limit peak share. TipRanks H.C. Wainwright analyst Matthew Caufield reiterated a buy rating and $44 target, but said the results “must be interpreted in the context of current therapy” for IgG4-RD as the market digests positioning and payer dynamics. 4
But the path from a statistical win to a commercial one is rarely straight in biotech, especially when investors lean on cross-trial comparisons to a marketed rival. Zenas still needs regulators to sign off on the submission package and label, and investors are watching whether the safety profile holds up as more patients remain on drug longer.
