Cyclophosphamide conditioning in patients with severe aplastic anaemia given unrelated marrow transplantation: a phase 1-2 dose de-escalation study. Lancet Haematol 2015 Sep;2(9):e367-75
Date
12/22/2015Pubmed ID
26685770Pubmed Central ID
PMC4861234DOI
10.1016/S2352-3026(15)00147-7Scopus ID
2-s2.0-84954025938 (requires institutional sign-in at Scopus site) 64 CitationsAbstract
BACKGROUND: The optimum preparative regimen for unrelated donor marrow transplantation in patients with severe aplastic anaemia remains to be established. We investigated whether the combination of fludarabine, anti-thymocyte globulin, and total body irradiation (TBI) would enable reduction of the cyclophosphamide dose to less than 200 mg/kg while maintaining engraftment and having a survival similar to or better than that with standard regimens using a cyclophosphamide dose of 200 mg/kg (known to be associated with significant organ toxicity) for unrelated donor transplantation for severe aplastic anaemia. We have previously shown that cyclophosphamide at 150 mg/kg resulted in excess toxicity and its omission (0 mg/kg) resulted in unacceptable graft failure (three of three patients had secondary graft failure). Here we report results for the 50 mg/kg and 100 mg/kg cohorts.
METHODS: In a multicentre phase 1-2 study, patients (aged ≤65 years) with severe aplastic anaemia, adequate organ function, and an unrelated adult marrow donor HLA matched at the allele level for HLA A, B, C, and DRB1 or mismatched at a single HLA locus received bone marrow grafts from unrelated donors. All patients received anti-thymocyte globulin (rabbit derived 3 mg/kg per day, intravenously, on days -4 to -2, or equine derived 30 mg/kg per day, intravenously, on days -4 to -2), fludarabine (30 mg/m(2) per day, intravenously, on days -5 to -2), and TBI (2 Gy). Cyclophosphamide dosing started at 150 mg/kg and was de-escalated in steps of 50 mg/kg (to 100 mg/kg, 50 mg/kg, and 0 mg/kg). The primary endpoint was the selection of the optimum cyclophosphamide dose based on assessments of graft failure (primary or secondary), toxicity, and early death during 100 days of follow-up after the transplant; this is the planned final analysis for the primary endpoint. This trial is registered with ClinicalTrials.gov, number NCT00326417.
FINDINGS: 96 patients had bone marrow transplant. At day 100, 35 (92%) of 38 patients were engrafted and alive in the cyclophosphamide 50 mg/kg cohort and 35 (85%) of 41 in the 100 mg/kg cohort. Cyclophosphamide 50 mg/kg and 100 mg/kg resulted in posterior means for fatality without graft failure of 0·7% (credible interval 0-3·3) and 1·4% (0-4·9), respectively. Three patients (8%) had graft failure with cyclophosphamide 50 mg/kg and six (15%) with cyclophosphamide 100 mg/kg. Four (11%) patients had major regimen-related toxicity with cyclophosphamide 50 mg/kg and nine (22%) with cyclophosphamide 100 mg/kg. The most common organ toxicity was pulmonary (grade 3 or 4 dyspnoea or hypoxia including mechanical ventilation), and occurred in three (8%) and four (10%) patients given cyclophosphamide 50 mg/kg and 100 mg/kg, respectively.
INTERPRETATION: Cyclophosphamide at 50 mg/kg and 100 mg/kg with TBI 2 Gy, fludarabine, and anti-thymocyte globulin results in effective conditioning and few early deaths after unrelated donor transplantation for severe aplastic anaemia. These doses of cyclophosphamide provide a framework for further regimen optimisation strategies.
FUNDING: US National Heart, Lung, and Blood Institute and National Cancer Institute.
Author List
Anderlini P, Wu J, Gersten I, Ewell M, Tolar J, Antin JH, Adams R, Arai S, Eames G, Horwitz ME, McCarty J, Nakamura R, Pulsipher MA, Rowley S, Leifer E, Carter SL, DiFronzo NL, Horowitz MM, Confer D, Deeg HJ, Eapen MAuthors
Mary Eapen MBBS, DCh, MRCPI, MS Professor in the Medicine department at Medical College of WisconsinMary M. Horowitz MD, MS Professor in the Medicine department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdolescentAdult
Aged
Anemia, Aplastic
Bone Marrow Transplantation
Child
Child, Preschool
Cyclophosphamide
Female
Graft vs Host Disease
Humans
Immunosuppressive Agents
Infant
Male
Middle Aged
Transplantation Conditioning
Young Adult