To Evaluate Efficacy of Belinostat or Pralatrexate in Combination Against CHOP Alone in PTCL

Part 1: This is a 5 Arm study primarily to determine the best dose out of the two dose levels of Belinostat and Pralatrexate combined with CHOP/COP in newly diagnosed PTCL patients based on Safety for part 2 study.

Part 2 (Efficacy and Safety): This is a 3 Arm study. Patients with previously untreated PTCL will be randomized 1:1:1 into 1 of 3 treatment groups: 2 experimental treatment groups (Bel-CHOP or Fol-COP) or 1 active comparator treatment group (CHOP). Patients will be treated for up to 6 cycles. The primary objective is to compare the Progression Free Survival of patients with newly diagnosed PTCL treated for up to 6 cycles with Beleodaq (belinostat) in combination with CHOP (Bel-CHOP) or Folotyn (pralatrexate injection) in combination with COP (Fol-COP) to CHOP alone.