FDA Wants Additional Data Before Approving Citius’s Lymphir for T-Cell Lymphoma

Rare Daily Staff

The U.S. Food and Drug Administration notified Citius Pharmaceuticals that it would not approve the company’s Biologics License Application seeking approval for Lymphir, its experimental treatment for the rare blood cancer relapsed or refractory cutaneous T-cell lymphoma after at least one prior systemic therapy.

The agency told Citius that it would need to incorporate enhanced product testing, and additional controls agreed to with the FDA during the market application review. There were no concerns relating to the safety and efficacy clinical data package submitted with the application, or the proposed prescribing information.

Cutaneous T-cell lymphoma (CTCL) is a type of cutaneous non-Hodgkin lymphoma 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 and Sézary Syndrome 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 systemic 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.

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 diftitox received regulatory approval in Japan for the treatment of CTCL and peripheral T-cell lymphoma. 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.

“We appreciate the FDA’s expeditious review of our application. We intend to provide additional data and remain fully engaged with the FDA as we continue to work toward approval,” said Leonard Mazur, chairman and CEO of Citius. “We remain confident in the potential of Lymphir to become an important addition to the treatment landscape for patients with relapsed or refractory CTCL and make a meaningful difference in their lives.”

Photo: Leonard Mazur, chairman and CEO of Citius