FDA Approves Citius Pharmaceuticals' LYMPHIR™ for Relapsed/Refractory Cutaneous T-Cell Lymphoma

Citius Pharmaceuticals, Inc. (NASDAQ: CTXR) has announced that the U.S. Food and Drug Administration (FDA) approved LYMPHIR™ (denileukin diftitox-cxdl), a new immunotherapy for treating relapsed or refractory (r/r) cutaneous T-cell lymphoma (CTCL) in patients who have undergone at least one prior systemic therapy. LYMPHIR targets the interleukin-2 (IL-2) receptor on malignant T-cells and Tregs, making it the only CTCL therapy to do so. This marks the first approval of a novel targeted systemic therapy for r/r CTCL by the FDA since 2018 and is the first FDA-approved product for Citius Pharmaceuticals.

Leonard Mazur, CEO of Citius Pharmaceuticals, expressed optimism about LYMPHIR’s potential. He highlighted its capacity to reduce skin disease and control symptomatic itching without cumulative toxicity. The introduction of LYMPHIR is anticipated to expand the CTCL treatment landscape and grow the market, currently valued between $300-$400 million. Mazur emphasized Citius's commitment to ensuring timely access for all r/r CTCL patients and stated that LYMPHIR is expected to launch in the U.S. within the next five months.

Dr. Myron Czuczman, Chief Medical Officer of Citius Pharmaceuticals, elaborated on LYMPHIR’s unique IL-2 receptor-targeted mechanism. This treatment directly kills tumor cells and depletes host Tregs to boost the immune response, thus offering significant benefits to patients. It provides a novel option for Stage I-III r/r CTCL patients dealing with debilitating skin involvement.

CTCL is a rare and often chronic non-Hodgkin lymphoma that primarily affects the skin, with approximately 2,500-3,000 new diagnoses annually in the U.S. Patients with r/r CTCL face limited treatment options and usually cycle through several therapies until the disease progresses or becomes resistant. The main goal of CTCL treatment is to manage skin plaques and itching without cumulative toxicity. LYMPHIR offers a valuable new treatment option with a unique mechanism that targets and eradicates malignant T-cells while preserving healthy tissue.

Dr. Francine Foss, Professor of Hematology at Yale Cancer Center, stressed the importance of controlling the skin involvement in r/r CTCL, given the disease’s impact on patients’ quality of life. LYMPHIR provides hope in reducing skin disease and addressing the unmet needs of CTCL patients who are unable to complete or continue previous therapies.

The FDA's approval of LYMPHIR is based on results from the Phase 3 Pivotal Study 302, which included patients with stage I-III CTCL who had previously received a median of 4 prior anticancer therapies. The study demonstrated a 36% Objective Response Rate (ORR), with 84% of patients showing a reduction in skin disease and 31.7% experiencing clinically significant pruritus improvement. Importantly, no cumulative toxicity was observed in these patients.

LYMPHIR's safety profile aligns with the known safety profile for denileukin diftitox. Common adverse reactions included increased transaminases, decreased albumin, nausea, edema, and fatigue, among others. Serious visual impairment and infusion-related reactions were also noted. A boxed warning highlights the risk of capillary leak syndrome (CLS), which can be life-threatening or fatal. Monitoring and appropriate medical management are recommended to mitigate these risks.

As part of the approval, the FDA has mandated a postmarketing requirement for Citius to characterize the risk of visual impairment in CTCL patients treated with LYMPHIR. Citius remains committed to patient safety and will continue monitoring emerging safety data.

In summary, LYMPHIR represents a significant advancement in the treatment of r/r CTCL, providing a new therapeutic option with a novel mechanism of action. Its approval is a milestone for Citius Pharmaceuticals as they prepare for its launch in the U.S. market.