Pralatrexate has been approved for use as a single agent for treating patients with refractory or relapsed peripheral T-cell lymphoma, the Food and Drug Administration announced on Sept. 25.The first treatment ever approved for this rare, often aggressive type of non-Hodgkin's lymphoma, the new drug is expected to available in the United States in October, according to Allos Therapeutics Inc., of Westminster, Colo. Allos plans to market pralatrexate, which is administered intravenously, as Folotyn.Pralatrexate...