Citius Oncology Signs U.S. Distribution Agreement with McKesson to Support LYMPHIR™ Commercial Launch

McKesson joins leading distribution service providers as authorized U.S. distributor of LYMPHIR

CRANFORD, N.J., Oct. 20, 2025 /PRNewswire/ -- Citius Oncology, Inc. ("Citius Oncology") (Nasdaq: CTOR), the oncology-focused subsidiary of Citius Pharmaceuticals, Inc. ("Citius Pharma") (Nasdaq: CTXR), today announced it has entered into a distribution services agreement with McKesson Corporation (NYSE: MCK), one of the largest pharmaceutical distributors and healthcare services companies in North America. Under the agreement, McKesson will serve as an authorized distributor of record for LYMPHIR (denileukin diftitox-cxdl), a novel immunotherapy approved by the U.S. Food and Drug Administration (FDA) for the treatment of adult patients with relapsed or refractory Stage I-III cutaneous T-cell lymphoma (CTCL) after at least one prior systemic therapy.

The agreement with McKesson completes Citius Oncology's core U.S. distribution network for LYMPHIR, which now includes all three of the largest pharmaceutical distributors in the country. This strategic milestone ensures broad and reliable access to the therapy in preparation for its planned commercial launch in the fourth quarter of 2025.

"This agreement marks the final major component of our U.S. distribution strategy and reflects our deep commitment to ensuring that physicians and patients have timely access to LYMPHIR," said Leonard Mazur, Chairman and CEO of Citius Oncology and Citius Pharmaceuticals. "With a complete top-tier distribution network in place, we believe we are well-positioned to deliver on our promise to the CTCL community and execute a successful launch."

Headquartered in Irving, Texas, McKesson Corporation is a global leader in healthcare supply chain management, medical products distribution, and pharmaceutical logistics. The company supports thousands of hospitals, clinics, and pharmacies across the United States, making it a critical partner for enabling access to life-saving therapies like LYMPHIR.

Citius Oncology has now finalized distribution agreements with all three of the largest U.S. pharmaceutical wholesalers and specialty distributors, paving the way for broad national access across both academic centers and community oncology practices. These efforts complement the Company's ongoing commercialization activities, including inventory readiness, market access infrastructure, permanent J-code assignment (J9161), NCCN guideline inclusion, and a robust suite of provider and patient education resources.

About LYMPHIR™ (denileukin diftitox-cxdl)

LYMPHIR 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 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.

In 2021, denileukin diftitox received regulatory approval in Japan for the treatment of CTCL and PTCL. Subsequently, in 2021, Citius acquired an exclusive license with rights to develop and commercialize LYMPHIR in all markets except for Japan and certain parts of Asia. LYMPHIR was approved by the FDA in August 2024.

About Cutaneous T-cell Lymphoma

Cutaneous T-cell lymphoma is a type of cutaneous non-Hodgkin lymphoma (NHL) that comes in a variety of forms and is the most common type of cutaneous lymphoma. In CTCL, T-cells, a type of lymphocyte that plays a role in the immune system, become cancerous and develop into skin lesions, leading to a decrease in the quality of life of patients with this disease due to severe pain and pruritus. Mycosis Fungoides (MF) and Sézary Syndrome (SS) comprise the majority of CTCL cases.  Depending on the type of CTCL, the disease may progress slowly and can take anywhere from several years to upwards of ten to potentially reach tumor stage. However, once the disease reaches this stage, the cancer is highly malignant and can spread to the lymph nodes and internal organs, resulting in a poor prognosis. Given the duration of the disease, patients typically cycle through multiple agents to control disease progression. CTCL affects men twice as often as women and is typically first diagnosed in patients between the ages of 50 and 60 years of age. Other than allogeneic stem cell transplantation, for which only a small fraction of patients qualify, there is currently no curative therapy for advanced CTCL.

INDICATION

LYMPHIR 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.

IMPORTANT SAFETY INFORMATION

BOXED WARNING: CAPILLARY LEAK SYNDROME

Capillary 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.

WARNINGS AND PRECAUTIONS

Capillary Leak Syndrome

LYMPHIR 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