Zenas BioPharma Shares Plunge 51.86% Following Disappointing Phase 3 Trial Results

Written by Emily J. Thompson, Senior Investment Analyst

ZBIO+3.88%

Source: PRnewswire

Updated: Jan 09 2026

0mins

Source: PRnewswire

Stock Price Plunge: Zenas BioPharma's shares fell 51.86% to close at $16.61 on January 5, 2026, after the company announced that its IgG4-RD drug trial results did not meet commercial viability standards, indicating strong market disappointment in its product prospects.
Trial Results Analysis: Although Zenas characterized the trial results as 'positive', analysts noted that the drug's efficacy fell short of the expected threshold for commercialization, severely undermining investor confidence and further impacting the company's stock price.
CEO Acknowledges Disappointment: During a conference call on January 6, 2026, Zenas's CEO admitted that the hazard ratio did not meet market expectations, leading to an additional 8.49% drop in stock price to $15.20, reflecting growing investor concerns about the company's future.
Legal Investigation Initiated: Pomerantz LLP is investigating whether Zenas and its executives engaged in securities fraud or other unlawful business practices, which could further impact the company's reputation and shareholder confidence, increasing legal risks.

ZBIO

$20.07+Infinity%1D

Analyst Views on ZBIO

Wall Street analysts forecast ZBIO stock price to rise over the next 12 months. According to Wall Street analysts, the average 1-year price target for ZBIO is 41.20 USD with a low forecast of 19.00 USD and a high forecast of 55.00 USD. However, analyst price targets are subjective and often lag stock prices, so investors should focus on the objective reasons behind analyst rating changes, which better reflect the company's fundamentals.

5 Analyst Rating

4 Buy

1 Hold

0 Sell

Strong Buy

Current: 19.320

Low

19.00

Averages

41.20

High

55.00

Current: 19.320

Low

19.00

Averages

41.20

High

55.00

Citi

Buy

downgrade

$46 -> $43

2026-01-05

Reason

Citi

Price Target

$46 -> $43

AI Analysis

2026-01-05

downgrade

Buy

Reason

Citi lowered the firm's price target on Zenas BioPharma to $43 from $46 and keeps a Buy rating on the shares after the company announced Phase 3 INDIGO results for obexelimab in IgG4-RD. A weaker hazard ratio than Uplizna's has resulted in a selloff to levels below the firm's "ultra-bear case" of $18 per share, which implies zero contribution for obex in IgG4-RD, the analyst says. The firm remains confident obexelimab will be approved and recommends investors seeking discounted opportunities at the outset of 2026 buy the stock, noting that its revised target reflects model adjustments based on increasing its view of the odds of success for obex in IgG4-RD to 80% from 60%, offset by slightly lower peak share estimates.

Morgan Stanley

Overweight -> Equal Weight

downgrade

$37 -> $19

2026-01-05

Reason

Morgan Stanley

Price Target

$37 -> $19

2026-01-05

downgrade

Overweight -> Equal Weight

Reason

Morgan Stanley downgraded Zenas BioPharma to Equal Weight from Overweight with a price target of $19, down from $37, after the company announced top-line results from the Phase 3 INDIGO study evaluating obexelimab in IgG4-RD. While INDIGO met its primary endpoint, demonstrating a 56% reduction in the risk of IgG4-RD flare vs. placebo, the results fell short of the benchmark set by Uplizna, which demonstrated an 87% reduction in IgG4-RD flare risk versus placebo, the analyst tells investors. Obexelimab likely has a place in IgG4-RD based on the trial results, but peak share may be lower than previously anticipated, the analyst added.

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Morgan Stanley

Judah Frommer

Overweight

maintain

$34 -> $37

2025-11-13

Reason

Morgan Stanley

Judah Frommer

Price Target

$34 -> $37

2025-11-13

maintain

Overweight

Reason

Morgan Stanley analyst Judah Frommer raised the firm's price target on Zenas BioPharma (ZBIO) to $37 from $34 and keeps an Overweight rating on the shares after the company reported its Q3 update. The "highly anticipated" Phase 3 INDIGO results in IgG4-RD expected around year-end "should offer another opportunity for positive share inflection" if obexelimab data are competitive with Amgen's (AMGN) Uplizna, the analyst tells investors.

H.C. Wainwright

Buy

upgrade

$30 -> $44

2025-10-28

Reason

H.C. Wainwright

Price Target

$30 -> $44

2025-10-28

upgrade

Buy

Reason

H.C. Wainwright raised the firm's price target on Zenas BioPharma to $44 from $30 and keeps a Buy rating on the shares. The firm says obexelimab achieved the primary endpoint of 95% relative reduction in new gadolinium (Gd)-enhancing T1 lesions versus placebo in the Phase 2 MoonStone trial.

About ZBIO

Zenas BioPharma, Inc. is a clinical-stage global biopharmaceutical company focused on the development and commercialization of transformative therapies for patients with autoimmune diseases. The Company's lead product candidate, obexelimab, is a bifunctional monoclonal antibody designed to bind both CD19 and FcyRIIb, which are broadly present across B cell lineage, to inhibit the activity of cells that are implicated in many autoimmune diseases without depleting them. The Company is developing obexelimab as a potential immunology and inflammation (I&I) franchise for patients in several autoimmune diseases. The first three indications it is pursuing include immunoglobulin G4-related disease (IgG4-RD), relapsing multiple sclerosis (RMS) and systemic lupus erythematosus (SLE). Its other programs include ZB002 (an anti-TNFα monoclonal antibody), ZB004 (a CTLA-4-Ig fusion), and ZB001 and related programs. ZB002 is a recombinant human monoclonal antibody directed at human TNFα.

About the author

Emily J. Thompson

Emily J. Thompson, a Chartered Financial Analyst (CFA) with 12 years in investment research, graduated with honors from the Wharton School. Specializing in industrial and technology stocks, she provides in-depth analysis for Intellectia’s earnings and market brief reports.