Allos Therapeutics, Inc. is a biopharmaceutical company focused on the development and commercialization of anti-cancer therapeutics. As of December 31, 2011, the Company focused on the development and commercialization of FOLOTYN (pralatrexate injection). FOLOTYN is a folate analogue metabolic inhibitor designed to accumulate preferentially in cancer cells. FOLOTYN targets the inhibition of dihydrofolate reductase (DHFR), an enzyme critical in the folate pathway, thereby interfering with deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) synthesis and triggering cancer cell death. FOLOTYN can be delivered as a single agent, for which the Company has approval for the treatment of patients with relapsed or refractory peripheral T-cell lymphoma (PTCL), and can be used in combination therapy regimens. On September 5, 2012, Spectrum Pharmaceuticals, Inc. acquired Allos Therapeutics, Inc.