On July 3, the FDA granted accelerated approval to Beleodaq, a histone deacetylase inhibitor, for the treatment of patients with relapsed or refractory peripheral T-cell lymphoma.

The FDA approved Beleodaq (belinostat; Spectrum Pharmaceuticals) on July 3 for the treatment of patients with relapsed or refractory peripheral T-cell lymphomas (PTCL), a rare and aggressive group of diseases that accounts for 10% to 15% of all non-Hodgkin lymphomas.

PTCL is difficult to treat, and patients often relapse after first-line treatment, usually combination chemotherapy such as CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone). “Anything we can add to the armamentarium is helpful,” says Eric D. Jacobsen, MD, an oncologist at Dana-Farber Cancer Institute in Boston, MA.

Beleodaq inhibits histone deacetylases (HDAC), enzymes involved in the regulation of genes linked to tumorigenesis and cancer progression. It is the third drug to receive FDA approval for PTCL since 2009. Folotyn (pralatrexate; Spectrum Pharmaceuticals) received accelerated approval in 2009 for patients with relapsed or refractory PTCL, and Istodax (romidepsin; Celgene), another HDAC inhibitor, was approved in 2011 for patients who had received at least one prior therapy. Beleodaq received accelerated approval, a designation given to drugs that fill an unmet medical need.

The FDA based its approval on results from a multicenter, phase II trial of 120 evaluable patients with relapsed or refractory PTCL. In the trial, 10.8% of patients experienced a complete response and 15% had a partial response. The most common adverse effects, which occurred in more than a quarter of study participants, included nausea, fatigue, pyrexia, anemia, and vomiting.

Jacobsen, an investigator on an earlier phase II trial of Beleodaq, notes that in the BELIEF trial, which led to the FDA approval, the overall response rates were comparable to those of Folotyn and Istodax. The response rate was even higher—45.5%—in patients with angioimmunoblastic T-cell lymphoma, a common subtype of PTCL. Jacobsen called those results “very encouraging.”

As part of the approval process, the drug's sponsor, Spectrum Pharmaceuticals, is required to conduct a phase III trial to compare the efficacy of Beleodaq combined with CHOP versus CHOP alone, to establish whether the drug would be effective in first-line treatment as well.

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