Citius Pharmaceuticals, Inc. announced the resubmission of the Company's Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for LYMPHIR (denileukin diftitox), an IL-2-based immunotherapy for the treatment of patients with relapsed or refractory cutaneous T-cell lymphoma (CTCL) after at least one prior systemic therapy. The resubmission follows ongoing engagement with the FDA resulting from a Complete Response Letter (CRL) received on July 28, 2023. Citius believes it has addressed enhanced product testing and additional manufacturing controls noted in the letter.

There were no safety or efficacy issues cited and no additional trials required. Based on Center for Drug Evaluation and Research timelines, FDA acceptance of the completed resubmission package and issuance of a Prescription Drug User Fee Act (PDUFA) date is expected within 30 days of resubmission. LYMPHIR is a recombinant fusion protein that combines the interleukin-2 (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. In 2011 and 2013, the FDA granted orphan drug designation to LYMPHIR for the treatment of PTCL and CTCL, respectively. In 2021, denileukin dift itox received regulatory approval in Japan for the treatment of CTCL and peripheral T-cell lymphoma (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. 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 Sezary 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. Citius previously announced plans to form Citius Oncology, a standalone publicly traded company with LYMPHIR as its primary asset.

LYMPHIR received orphan drug designation by the FDA for the treatment of CTC Lymphoma. In addition, Citius completed enrollment in its Phase 2b trial of CITI-002 (Halo-Lido), a topical formulation for the relief of hemorrhoids. One 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.