Lymphir: US approves therapy for rare blood cancer

The US Food and Drug Administration has approved Lymphir, Citius Pharmaceuticals’ therapy, for patients with a form of blood cancer who have received at least one prior treatment, the company said on Thursday, an year after the regulator rejected the treatment.

The therapy, called Lymphir, is approved to treat certain adult patients with relapsed cutaneous T-cell lymphoma, a group of rare blood cancers that affects the skin. About 2,500-3,000 patients are diagnosed each year, the company estimated.

The company plans to launch the therapy in the next five months and said it would price it at comparable levels with existing treatments in the market.

The health regulator had declined to approve the therapy in July last year, and had sought additional product testing data.

The prescribing information for Lymphir carries the FDA’s serious “boxed warning”, flagging a life-threatening risk of a rare blood condition called capillary leak syndrome.

Capillary leak syndrome causes blood plasma to escape through tiny blood vessels and leads to a rapid drop in blood pressure.

About LYMPHIR™ (denileukin diftitox-cxdl)

LYMPHIR is a targeted immune therapy for r/r (R/R) 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.