RecruitingDrug trialIOMAB-CAR-T Followed by CAR-T Cell Therapy in R/R DLBCLThis study is being done to determine the safety, efficacy and tolerability of a single 50 mCi dose of 131I-Apamistamab given prior to FDA approved (commercially available) infusion in patients with Relapsed or refractory (R/R) non-Hodgkin lymphoma.