biostudies-literatureUnknown7(3)Tran MCRelapse after allogeneic stem cell transplantation (allo-SCT) remains the primary cause of treatment failure. A second SCT can result in long-term survival in a subset of patients, but the relapse rate remains high. We conducted a single-center, phase 1, modified 3 + 3 dose-escalation study of the feasibility of combining intensity-modulated total marrow irradiation (IM-TMI) with fludarabine and melphalan for conditioning. Between December 2015 and May 2020, 21 patients with relapsed hematologic disease undergoing second or greater allo-SCT were treated with IM-TMI doses of 6 Gy, 9 Gy, or 12 Gy. Dose-limiting toxicity was defined as a grade 3 or higher treatment-related adverse event; mucositis was the primary dose-limiting toxicity. The median times to neutrophil and platelet engraftment Blood advances285-292https://www.ebi.ac.uk/biostudies/studies/S-EPMC9898602biostudies-literatureA phase 1 trial utilizing TMI with fludarabine-melphalan in patients with hematologic malignancies undergoing second allo-SCT.PMC9898602Liu HArtz ASWang AHasan YStock WLarson RAKline JWeichselbaum RAydogan BTran MCRiedell PABishop MRYenice KPartouche JKosuri SLaBelle JLfalseA phase 1 trial utilizing TMI with fludarabine-melphalan in patients with hematologic malignancies undergoing second allo-SCT.Relapse after allogeneic stem cell transplantation (allo-SCT) remains the primary cause of treatment failure. A second SCT can result in long-term survival in a subset of patients, but the relapse rate remains high. We conducted a single-center, phase 1, modified 3 + 3 dose-escalation study of the feasibility of combining intensity-modulated total marrow irradiation (IM-TMI) with fludarabine and melphalan for conditioning. Between December 2015 and May 2020, 21 patients with relapsed hematologic disease undergoing second or greater allo-SCT were treated with IM-TMI doses of 6 Gy, 9 Gy, or 12 Gy. Dose-limiting toxicity was defined as a grade 3 or higher treatment-related adverse event; mucositis was the primary dose-limiting toxicity. The median times to neutrophil and platelet engraftment 2023-01-01T00:00:00Z2023 Feb2025-04-27T02:57:10.52Z2025-04-06T18:38:59.111ZS-EPMC98986023585159310.1182/bloodadvances.2022007530