Testing the Addition of an Anti-cancer Drug, Hu5F9-G4 (Magrolimab), to the Usual Chemotherapy Treatment (Mogamulizumab) in T-Cell (a Type of Immune Cell) Lymphoma That Has Returned After Treatment or Does Not Respond to Treatment

This phase Ib/II trial identifies the best dose and possible benefits and/or side effects of magrolimab when given in combination with mogamulizumab in treating patients with stage IB-IV mycosis fungoides or Sezary syndrome types of T-cell lymphoma that has come back (relapsed) or does not respond to treatment (refractory). Magrolimab and mogamulizumab are monoclonal antibodies that may interfere with the ability of cancer cells to grow and spread. Treatment with magrolimab in combination with mogamulizumab may stabilize cancer for longer period than the usual treatment in patients with relapsed/refractory T-cell lymphoma who have been previously treated.