Zenas BioPharma Announces Key 2024 Accomplishments and 2025 Business Objectives to Support the Global Development and Commercialization of Therapies for Autoimmune Diseases - Advancing Phase 2 and Phase 3 trials of obexe

Zenas BioPharma Announces Key 2024 Accomplishments

and 2025 Business Objectives to Support the Global Development and Commercialization of Therapies for Autoimmune Diseases

- Advancing Phase 2 and Phase 3 trials of obexelimab,

a unique CD-19 x Fc RIIb inhibitor of B cell function-

-Topline results from Phase 2 Trial in Relapsing

Multiple Sclerosis (MoonStone) expected in third quarter 2025-

-Topline results from pivotal Phase 3 Trial

in Immunoglobulin G4-Related Disease (INDIGO) expected year-end 2025-

- Enrollment of Phase 2 Trial in Systemic Lupus

Erythematosus (SunStone) expected to be completed in 2025-

- Out-licensed greater-China anti-IGF-1R Thyroid

Eye Disease programs to Zai Lab -

WALTHAM, Mass, February 5, 2025 (GLOBE NEWSWIRE)

- Zenas BioPharma, Inc. ("Zenas" or the "Company") (Nasdaq: ZBIO), a clinical-stage global biopharmaceutical

company committed to being a leader in the development and commercialization of therapies for autoimmune diseases, today announced

its 2024 accomplishments, outlined its key business objectives for 2025 and announced preliminary unaudited cash balance as of year-end

"Based upon the progress achieved across

all of our corporate goals and objectives during 2024, we enter 2025 with an opportunity to achieve major value-driving milestones with

the anticipated results from our ongoing obexelimab Phase 2 and Phase 3 clinical trials," said Lonnie Moulder, Founder and Chief

Executive Officer of Zenas. "We are extremely proud of the accomplishments of our dedicated team as we enter the year well-financed

and able to focus on execution, and achievement of our key objectives for the year."

The Company enters 2025 well-capitalized to deliver

its key milestones with approximately $350 million in cash, cash equivalents, and short-term investments as of December 31, 2024,1 which is expected to fund its operating expenses and capital expenditure requirements into the fourth quarter of 2026.

This amount is preliminary and unaudited and is subject to completion of the Company's financial closing procedures. As a

result, this amount may differ materially from the amount that will be reflected in the Company's consolidated financial statements

for the year ended December 31, 2024.

2024 Accomplishments and Recent Achievements

During 2024, the Company achieved the following

objectives and announced a recent business development transaction:

Anticipated 2025 Clinical Milestones for Obexelimab

Obexelimab is a bifunctional monoclonal antibody

designed to bind both CD19 and Fc RIIb, which are broadly present across B cell lineage, to inhibit the activity of cells that are

implicated in many autoimmune diseases without depleting them. This unique mechanism of action and self-administered, subcutaneous once-weekly

injection regimen may broadly and effectively address the pathogenic role of B cell lineage in chronic autoimmune disease. Obexelimab

has been evaluated in five completed clinical trials in a total of 198 patients who received obexelimab either as an intravenous infusion

or as a subcutaneous injection. Obexelimab was well tolerated and demonstrated clinical activity across these five clinical trials, providing

the Company an initial clinical proof of concept for obexelimab as a potent B cell inhibitor for the treatment of patients living with

certain autoimmune diseases.

During 2025, the Company expects to achieve the

following key clinical milestones:

The role of B cells in the pathogenesis

of multiple sclerosis including RMS has been demonstrated through the successful clinical development, approval and clinical use of anti-CD20

B cell targeting therapies of other companies, including OCREVUS (ocrelizumab) and KESIMPTA (ofatumumab), which selectively

deplete CD20-expressing B cells. The Company believes obexelimab's unique mechanism of action to potently inhibit but not deplete

a broader B cell lineage than CD20, nonclinical data, and a subcutaneous injection regimen, supports its potential for the treatment of

More information on the Phase 2 MoonStone

trial (NCT06564311) is available at clinicaltrials.gov

IgG4-RD is a chronic fibro-inflammatory

disease that can affect virtually all organ systems, including the pancreas, biliary tract, salivary and lacrimal glands, lungs, and kidneys.

Patients with IgG4-RD may present with a single organ involved but more frequently present with multiple organ involvement. As the disease

progresses and patients experience new or worsening symptoms (i.e., flares), lesions develop in additional organs and the cellular inflammation

characterizing early disease moves toward a more fibrotic stage, which can lead to major irreversible tissue damage and ultimately organ

failure. We estimate that the currently diagnosed population of IgG4-RD patients in the U.S. is approximately 20,000, with comparable

prevalence rates globally.

Despite the growing recognition of IgG4-RD

and advances in the understanding of its pathophysiology, there are no approved therapies for the treatment of this disease and there

remains high unmet medical need. The current standard of care is treatment with glucocorticoids (GCs). Although GCs are initially effective,

treatment with GCs can often result in various complications and co-morbidities. Most patients can relapse within 12 months of discontinuing

GC treatment, and maintenance therapy with GCs has not been shown to prevent recurrence of disease.

The pathogenesis of IgG4-RD suggests

that B cell-targeted therapies may provide therapeutic benefit. Although not approved by any regulatory authorities to treat IgG4-RD,

certain B cell depleting agents (e.g., rituximab) are occasionally administered to patients with IgG4-RD. However, B cell depleting agents

are often associated with infections, including serious opportunistic infections, and can compromise a patient's ability to mount

a response to vaccinations.

The reported evidence for the role of

B cells in the pathogenesis of IgG4-RD, the observed effects of B cell targeting agents in previous trials in IgG4-RD, the data from our

Phase 2 IgG4-RD trials with obexelimab, and its unique, non-depleting mechanism and once-weekly, subcutaneous injection regimen support

its development in patients with IgG4-RD.

More information on the Phase 3 INDIGO

trial (NCT05662241) is available at clinicaltrials.gov

The crucial role of B cells in SLE pathogenesis

is well recognized, from producing autoantibodies to abnormal regulation of immune responses. Moreover, SLE is an autoimmune disease characterized

by B cell dysfunction, the production of autoantibodies toward cellular and nuclear components, and multiorgan damage caused by immune

complex deposition and inflammation within affected tissues. Current treatments are limited in number and modestly effective. Obexelimab

has demonstrated clinical activity in a prior Phase 2 double-blind, randomized trial demonstrating proof-of-concept in the overall

trial population and increased response in patients who maintained higher systemic exposure to obexelimab, and also in biomarker-defined

subpopulations. Coupled with the safety data obtained to date, we believe these data provide support for the development of obexelimab

in patients with SLE.

More information on the Phase 2 SunStone

trial (NCT06559163) is available at clinicaltrials.gov

About Zenas BioPharma, Inc.

is a clinical-stage global biopharmaceutical company committed to becoming a leader in the development and commercialization of transformative therapies for patients with autoimmune diseases. Our core business strategy combines our experienced leadership team with a disciplined

product candidate acquisition approach to identify, acquire and develop product candidates globally that we believe can provide superior

clinical benefits to patients living with autoimmune diseases. Zenas' lead product candidate, obexelimab, is a bifunctional monoclonal

antibody designed to bind both CD19 and Fc RIIb, which are broadly present across B cell lineage, to inhibit the activity of cells

that are implicated in many autoimmune diseases without depleting them. We believe that obexelimab's unique mechanism of action

and self-administered, subcutaneous injection regimen may broadly and effectively address the pathogenic role of B cell lineage in chronic

Forward looking statements

This press release contains "forward-looking

statements" which involve risks, uncertainties and contingencies, many of which are beyond the control of the Company, which may

cause actual results, performance, or achievements to differ materially from anticipated results, performance, or achievements. All statements

other than statements of historical facts contained in this press release are forward-looking statements. In some cases, forward-looking

statements can be identified by terms such as "may," "will," "should," "expect," "plan,"

"anticipate," "could," "intend," "target," "project," "contemplate,"

"believe," "estimate," "predict," "potential" or "continue" or the negative

of these terms or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements

include, but are not limited to, statements concerning Zenas's plans, objectives, expectations and intentions; the timing and results

of ongoing and future clinical trials, including expectations on the timing of reporting INDIGO trial topline results, the 12-week primary

endpoint data for the MoonStone trial and the anticipated timing of completing enrollment and reporting topline results for the SunStone

trial; its growth strategy; the Company's preliminary unaudited cash, cash equivalents and short-term investments as of December 31,