Citius Oncology is focused on developing and commercializing LYMPHIR™ (denileukin diftitox-cxdl), a targeted immune therapy for an initial indication in the treatment of persistent or recurrent cutaneous T-cell lymphoma (CTCL), a rare form of non-Hodgkin lymphoma. 

LYMPHIR is a specially engineered IL-2-diphtheria toxin fusion protein made using recombinant DNA technology. It works by targeting cells that have IL-2 receptors with a toxin derived from diphtheria bacteria. Once inside the cell, this toxin stops the cell from making proteins, which leads to the cell's death. LYMPHIR has two main effects:

  • Directly kills tumor cells: It binds to IL-2 receptors and internalizes the diphtheria toxin directly into the tumor cells, causing them to die.
  • Boosts the immune response: It reduces the number of regulatory T cells (Tregs) that suppress the immune system, thereby enhancing the body's ability to fight the tumor.

How It Works



Cutaneous T-cell Lymphoma (CTCL)

CTCL is a subset of non-Hodgkin lymphomas predominantly affecting the skin. The most common types include Mycosis Fungoides (MF) and Sézary Syndrome (SS). Approximately 30,000 to 40,000 patients live with CTCL in the U.S., with an estimated annual incidence rate of 0.5/100,000 according to the National Cancer Institute. 

CTCL is a chronic disease. Despite existing therapeutic options to treat the disease, there remains a significant unmet medical need due to limitations in current treatments, such as toxicity and resistance. Available systemic agents are not curative, and the primary focus of treatment is to induce and maintain remission.

LYMPHIR is a novel targeted oncology asset with an attractive near-term revenue opportunity. LYMPHIR is now FDA approved. It is the only recombinant fusion protein in the CTCL treatment landscape.

Program Highlights

  • Phase 3 Pivotal trial completed December 2021.
  • The FDA approved LYMPHIR on August 7, 2024.

Important safety information and LYMPHIR’s full prescribing information may be accessed here.

Citius Oncology plans to further explore the potential of LYMPHIR to treat larger patient populations with additional indications in peripheral T-cell lymphoma (PTCL) and immuno-oncology.

Investigator-Initiated Trials

Citius Oncology is exploring the potential of LYMPHIR in immuno-oncology through two investigator-initiated trials.

University of Minnesota, Masonic Cancer Center 

  • Trial Type: Phase 1, single-arm, open-label
  • Initiated: June 2021
  • Enrollment: approximately 20
  • Objectives:
    • Part I will administer LYMPHIR before CAR-T therapies to establish the maximum tolerated dose (MTD); 
    • Part II will evaluate efficacy in patients with relapsed/refractory B-Cell Lymphoma
  • Trial Title: Phase I/II Trial Using E7777 to Enhance Regulatory T-Cell Depletion Prior to CAR-T Therapy. (NCT04855253)

University of Pittsburgh Medical Center, Hillman Cancer Center

    • Trial Type: Phase 1, single -arm, open-label
  • Initiated: September 2022
  • Enrollment: Part I will enroll 18-30 patients for dose escalation; Part II will enroll approximately 40 patients for dose expansion
  • Objectives:
    • Assess the safety and efficacy of LYMPHIR combined with pembrolizumab in patients with recurrent or metastatic solid tumors
    • Evaluate immune microenvironment changes and secondary endpoints like objective response, progression-free survival, and overall survival
  • Trial Title: The Efficacy of T-regulatory Cell Depletion with E7777 Combined with Immune Checkpoint Inhibitor, Pembrolizumab. (NCT05200559)

Both trials are ongoing and continue to enroll patients.