Citius Oncology Announces Preliminary Topline Phase 1 Data from Study of LYMPHIR (E7777) Dosing Prior to Commercial CAR-T Therapy in High-Risk Diffuse Large B-Cell Lymphoma Topline data of investigator-initiated study at

Oncology Announces Preliminary Topline Phase 1 Data from Study of LYMPHIR (E7777) Dosing Prior to Commercial CAR-T Therapy in

High-Risk Diffuse Large B-Cell Lymphoma

data of investigator-initiated study at the University of Minnesota and City of Hope demonstrates 86% overall response rate (OR), including

57% complete response (CR) and 29% partial response (PR)

was well-tolerated with no dose-limiting toxicities observed

N.J., March 4, 2026 - Citius Oncology, Inc. ("Citius Oncology") (Nasdaq: CTOR), an oncology-focused biopharmaceutical

company and majority-owned subsidiary of Citius Pharmaceuticals, Inc. ("Citius Pharma") (Nasdaq: CTXR), today announced positive

topline safety and efficacy results from an investigator-initiated Phase 1 trial evaluating LYMPHIR (E7777, denileukin diftitox-cxdl)

administered prior to commercial CD19-directed CAR-T therapy in patients with high-risk relapsed or refractory diffuse large B-cell lymphoma

(DLBCL). The trial was conducted by lead investigator, Dr. Veronika Bachanova, at the University of Minnesota and City of Hope. Full

results were presented at the 2026 ASTCT & CIBMTR Tandem Meetings1.

Phase 1 trial was designed to augment the lymphodepletion regimen prior to CAR-T infusion through the administration of LYMPHIR to potentially

improve the anti-tumor activity of CAR-T therapies. LYMPHIR, an engineered fusion toxin that preferentially binds to the IL-2 receptor

expressed on regulatory T-cells (Tregs), is currently FDA-approved and commercially available for the treatment of relapsed or refractory

cutaneous T-cell lymphoma (CTCL) after one prior systemic therapy.

Treg depletion prior to CAR-T infusion with LYMPHIR represents a promising immunomodulatory strategy in patients with high-risk DLBCL,

and these Phase 1 data provide an encouraging signal of the potential to enhance current CAR-T regimens," said Dr. Myron Czuczman,

Executive Vice President and Chief Medical Officer of Citius Oncology and Citius Pharma. "These positive data support our broader

strategy of exploring LYMPHIR's modulatory effect on Tregs in combination with other approved therapies to potentially enhance

the body's own immune system to fight cancerous tumors," he added.

Results & Study Design

Phase 1, open-label, dose-escalation study (NCT04855253), enrolled 14 patients with relapsed or refractory DLBCL exhibiting poor prognostic

features, including double/triple hit genetics, primary refractory disease, and extranodal involvement. Participants received one dose

of LYMPHIR (E7777) at 5, 7, or 9 g/kg followed by low dose chemotherapy prior to standard commercial CD19-directed CAR-T cell

therapy. All patients received an infusion of one of the following FDA-approved, commercially manufactured CAR-T products: axicabtagene

ciloleucel (Yescarta ; Kite Pharma/Gilead Sciences), lisocabtagene maraleucel (Breyanzi ; Bristol Myers

Squibb), or tisagenlecleucel (Kymriah ; Novartis).

use of LYMPHIR in this study was investigational and outside of its FDA-approved indication. The Phase 1 study was not designed or powered

to evaluate clinical efficacy, and no conclusions can be drawn regarding comparative effectiveness or long-term outcomes.

Findings from the Phase 1 Trial

this high-risk population, LYMPHIR showed a favorable safety profile and promising pharmacodynamic effects when administered prior to

CAR-T therapies. This data sets the stage for a larger study to assess its potential to enhance CAR-T efficacy through longer duration

of LYMPHIR use," said Dr. Veronika Bachanova, Principal Investigator and Professor of Medicine at the University of Minnesota.

Bachanova presented the topline data at the 2026 Tandem Meetings | ASTCT CIBMTR .

E7777 to Enhance Regulatory T-Cell Depletion Prior to CAR-T for High-Risk LBCL

Diffuse Large B-Cell Lymphoma (DLBCL)

large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL), accounting for approximately 30%-40% of

newly diagnosed cases in the United States. DLBCL is an aggressive and rapidly growing cancer of B lymphocytes, a type of white blood

cell responsible for producing antibodies. While frontline chemoimmunotherapy regimens such as R-CHOP can be curative for many patients,

up to 40% experience relapse or refractory disease. High-risk features are associated with poor outcomes and limited responses to standard

therapies, including CAR-T cell therapy. Novel strategies that modulate the tumor microenvironment, such as transient regulatory T-cell

depletion, are under investigation to improve treatment efficacy and long-term remission rates in this difficult-to-treat population.

LYMPHIR (denileukin diftitox-cxdl)

is a targeted immune therapy for relapsed or refractory cutaneous T-cell lymphoma (CTCL) indicated for use in Stage I-III disease after

at least one prior systemic therapy. It is a recombinant fusion protein that combines the IL-2 receptor binding domain with diphtheria

toxin (DT) fragments. The agent specifically binds to IL-2 receptors on the cell surface, causing diphtheria toxin fragments that have

entered cells to inhibit protein synthesis. After uptake into the cell, the DT fragment is cleaved and the free DT fragments inhibit

protein synthesis, resulting in cell death. Denileukin diftitox-cxdl demonstrated the ability to deplete immunosuppressive regulatory

T lymphocytes (Tregs) and antitumor activity through a direct cytocidal action on IL-2R-expressing tumors.

2021, denileukin diftitox received regulatory approval in Japan for the treatment of relapsed or refractory CTCL and peripheral T-cell

lymphoma (PTCL). Subsequently, in 2021, Citius acquired an exclusive license with rights to develop and commercialize denileukin diftitox

in all markets except for India, Japan and certain parts of Asia. LYMPHIR (denileukin diftitox-cxdl) was approved by the FDA and subsequently

launched in the U.S. in December 2025.

Citius Oncology, Inc.

Oncology, Inc. (Nasdaq: CTOR) is a platform to develop and commercialize novel targeted oncology therapies. In December 2025, Citius

Oncology launched LYMPHIR, approved by the FDA for the treatment of adults with relapsed or refractory Stage I-III CTCL who had

had at least one prior systemic therapy. Management estimates the initial market for LYMPHIR currently exceeds $400 million, is growing,

and is underserved by existing therapies. Robust intellectual property protections that span orphan drug designation, complex technology,

trade secrets and pending patents for immuno-oncology use as a combination therapy with checkpoint inhibitors would further support Citius

Oncology's competitive positioning. For more information, please visit www.citiusonc.com.

press release may contain "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933 and

Section 21E of the Securities Exchange Act of 1934. Such statements are made based on our expectations and beliefs concerning future

events impacting Citius Oncology. You can identify these statements by the fact that they use words such as "will," "anticipate,"

"estimate," "expect," "plan," "should," and "may" and other words and terms

of similar meaning or use of future dates. Forward-looking statements are based on management's current expectations and are subject

to risks and uncertainties that could negatively affect our business, operating results, financial condition and stock price. Factors

that could cause actual results to differ materially from those currently anticipated are: risks relating to the results of research

and development activities, including those from our existing and any new pipeline assets; early-stage clinical data may not be predictive

of results from larger or later-stage studies;, our need for substantial additional funds and our ability to raise additional money to

fund our operations for at least the next 12 months as a going concern; our ability to successfully commercialize LYMPHIR and establish

a sustainable revenue stream; the estimated markets for LYMPHIR and our product candidates and the acceptance thereof by any market;

our ability to secure strategic partnerships and expand international access to LYMPHIR; our ability to maintain Nasdaq's continued

listing standards; our ability to use the latest technology to support our commercialization efforts for LYMPHIR; physician and patient

acceptance of LYMPHIR in a competitive treatment landscape; our reliance on third-party logistics providers, distributors, and specialty

pharmacies to support commercial operations; our ability to educate providers and payers, secure adequate reimbursement, and maintain

uninterrupted product supply; post-marketing requirements and ongoing regulatory compliance related to LYMPHIR; the ability of LYMPHIR

and our product candidates to impact the quality of life of our target patient populations; our ability to procure cGMP commercial-scale

supply; our ability to obtain, perform under and maintain financing and strategic agreements and relationships; market and other conditions;

risks related to our growth strategy; patent and intellectual property matters; government regulation; as well as other risks described

in our Securities and Exchange Commission ("SEC") filings. These risks have been and may be further impacted by any future

public health risks. Accordingly, these forward-looking statements do not constitute guarantees of future performance, and you are cautioned

not to place undue reliance on these forward-looking statements. Risks regarding our business are described in detail in our SEC filings

which are available on the SEC's website at www.sec.gov, including in Citius Oncology's Annual Report on Form 10-K for the

year ended September 30, 2025, filed with the SEC on December 23, 2025. These forward-looking statements speak only as of the date hereof,

and we expressly disclaim any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements

contained herein to reflect any change in our expectations or any changes in events, conditions or circumstances on which any such statement

is based, except as required by law.

is a registered trademark of Kite Pharma, Inc., a Gilead company.

is a registered trademark of Bristol Myers Squibb.

is a registered trademark of Novartis.

(denileukin diftitox-cxdl)

is an IL2-receptor-directed cytotoxin indicated for the treatment of adult patients with r/r Stage I-III cutaneous T-cell lymphoma (CTCL)

after at least one prior systemic therapy.

WARNING: CAPILLARY LEAK SYNDROME

leak syndrome (CLS), including life-threatening or fatal reactions, can occur in patients receiving LYMPHIR. Monitor patients for signs

and symptoms of CLS during treatment. Withhold LYMPHIR until CLS resolves, or permanently discontinue based on severity.

can cause capillary leak syndrome (CLS), including life-threatening or fatal reactions. CLS was defined in the clinical trials as the

occurrence of at least 2 of the following symptoms at any time during LYMPHIR therapy: hypotension, edema, and serum albumin <3 g/dL.

These symptoms were not required to occur simultaneously to be characterized as capillary leak syndrome.