RecruitingPhase 2Drug trialMT2022-60: Ph 2 Study of Pembro+ BEAM With ASCT for Relapsed Hodgkin LymphomaThis is a Phase 2 single arm study to evaluate efficacy and safety of Pembrolizumab before with BEAM ASCT followed by Pembrolizumab maintenance for 1 year. Patients will receive 200 mg Pembrolizumab Q3week starting at day - 28 before stem cell transplant until 1 year after autologous stem cell transplant.