Pralatrexate (PDX) Offers Hope for some PTCL Patients

A chemotherapy agent called pralatrexate and developed by Allos Therapeutics could become the first FDA-approved agent to treat patients with relapsed or refractory Peripheral T-Cell Lymphoma (PTCL).

Allos Therapeutics' Phase II trial was called PROPEL (an acronym that stretches the definition of an acronym, standing for Pralatrexate in patients with Relapsed Or refractory PEripheral T-cell Lymphoma) and it was presented in December 2008 at the 50th Annual Meeting of the American Society of Hematology in San Francisco.

The study featured 115 patients and was the largest prospective clinical trial in patients with relapsed or refractory peripheral T-cell lymphoma. Patients in the study received weekly intravenous infusions of pralatrexate (30 mg/m^2) for seven weeks, along with vitamin B12 and folic acid to offset any potential side-effects from the pralatrexate.

What it found was that pralatrexate produced "complete responses (disappearance of all signs of cancer) in patients who had previously failed an average of three treatment regimens, including an autologous stem cell transplant for some patients."

The drug is designed to be imported selectively into cancer cells; as the level of pralatrexate adds up to high concentrations within the cancer cell, it eventually inhibits DNA synthesis and leads to cell death.

In the US, pralatrexate enjoys orphan drug status and fast track designation for treating PTCL, and in Europe it has orphan medicinal product designation for the same purpose.

Pending FDA approval, Pralatrexate will become the first drug FDA approved to treat relapsed or refractory PTCL. The FDA's decision has a deadline date of September 24, 2009.

Sources:

--"FDA Accepts Allos Therapeutics' Pralatrexate NDA for Filing and Grants Priority Review Status." Health & Beauty Close-Up. M2 Communications Ltd. 2009
--"Novel Treatments Demonstrate Improvements in Overall Survival and Response Rates in Difficult-To-Treat Forms of Leukemia and Lymphoma." US Newswire. 2008.