Reduced Intensity Conditioning for Hemophagocytic Syndromes or Selected Primary Immune Deficiencies (BMT CTN 1204)

HLH, HLH-related disorders, Chronic Granulomatous (CGD), HIGM1, Immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (IPEX) and severe LAD-I represent primary immune disorders that are typically fatal without Hematopoietic Cell Transplant (HCT). However, transplant is often complicated by inflammation, infection and other co-morbidities. In addition, these disorders have been shown to be cured with partial chimerism, making them an ideal target for the use of reduced intensity approaches, where a portion of patients may not achieve full donor chimerism, but instead achieve stable mixed chimerism. Reduced-intensity conditioning strategies have demonstrated improved survival with decreased Treatment Related Mortality (TRM) in institutional series for patients with HLH (Cooper et al., 2006; Marsh et al., 2010; Marsh et al., 2011). However, graft loss and unstable chimerism remain challenges. An institutional case series from Cincinnati Children's Hospital demonstrated full or high-level chimerism and improved durable engraftment using intermediate (Day -14) timing alemtuzumab (Marsh et al., 2013b). This study aims to test the efficacy of the Intermediate RIC strategy in a prospective multi-center study including HLH as well as other primary immunodeficiencies where allogeneic transplant with RIC has been shown to be feasible and stable chimerism is curative.

The primary goal of this Phase II clinical trial is to determine the one-year overall survival of patients treated for immune deficiencies including HLH, HLH-like disorders, CGD, HIGM1, IPEX syndrome, and severe LAD-I with Matched Related Donor (MRD)/ Matched Unrelated Donor (MUD) bone marrow transplant using a reduced-intensity conditioning strategy including intermediate-timing of alemtuzumab. The donor choice is an unaffected related bone marrow donor who is a 6/6 match at HLA-A, -B (intermediate or higher resolution) and -DRB1 (at high resolution using DNA-based typing) OR a 7/8 or 8/8 match for human leukocyte antigen (HLA)-A, -B, -C and -DRB1 (at high resolution using DNA-based typing), OR an unrelated bone marrow donor who is a 7/8 or 8/8 match at HLA-A, -B, -C and -DRB1 (at high resolution using DNA-based typing). The transplant conditioning regimen will include fludarabine, melphalan, and alemtuzumab starting at Day -14 (Flu/Mel/Alem). Graft Versus Host Disease (GVHD) prophylaxis will consist of cyclosporine and corticosteroids through engraftment. Post-transplant supportive care will include infection surveillance and prophylaxis, and disease-specific supportive care.