RecruitingPhase 2Drug trialRandomized Phase IIB Trial of Oral Azacytidine Plus Romidepsin Versus Investigator's Choice in PTCLThe purpose of this study is to find out whether the combination treatment of romidepsin and oral azacytidine is safe and effective in patients with Peripheral T-Cell Lymphoma (PTCL). This study will compare the experimental combination treatment of romidepsin and oral azacytidine to single agent drugs already determined effective in patients with PTCL. For the purposes of this study, the single agent drugs already used to treat lymphoma are called investigator's choice (IC), meaning the investigator will choose which one of these drugs to administer. The IC drug options include romidepsin, belinostat, pralatrexate or gemcitabine given alone. Funding Source: FDA OOPD.