Hematopoietic Stem Cell Transplantation at Home
Authors: Sung Anthony D. , Nichols Krista R. , Messina Julia A. , Romero Kristi , Dalton Tara , Bush Amy , Covington Megan , Shelby Rebecca , Frith Jennifer , Gasparetto Cristina J. , Horwitz Mitchell E. , Long Gwynn D. , Lopez Richard , Rizzieri David A. , Sarantopoulos Stefanie , Sullivan Keith M. , Chao Nelson J. 
Published: April 2021

Abstract

Introduction: Patients receiving autologous (auto) and allogeneic (allo) hematopoietic stem cell transplantation (HCT) typically undergo extensive inpatient hospitalizations, daily "day hospital" visits, or a combination of the two. This aspect of transplant poses a variety of challenges, ranging from nosocomial infections to hospital-induced delirium to lifestyle adjustments. By keeping patients at home, we may lower complications and improve quality of life, as well as potentially lower costs and resource utilization.
Methods: We conducted a phase 1 study of home HCT to investigate the safety and feasibility of implementing this strategy in the United States. Patients interested in participating needed to live within a 30 minute drive of a transplant center and underwent a home inspection to assess suitability and safety (e.g. absence of black mold). Eligible patients would still receive pre-transplant conditioning at the hospital or day hospital, but they would be discharged home after receiving their stem cell infusion. The goal was to keep trial participants at home for the duration of transplant. In the morning, nurse practitioners or physician assistants made daily house calls to conduct assessments, examine patients, and draw blood for laboratory studies. These studies were run at the hospital, and in the afternoon a nurse returned to the patient's home to provide home blood transfusions, home intravenous fluids, electrolytes, or antibiotics, or other interventions. If an acute event occurred that could not be safely managed at home (e.g. first evaluation of febrile neutropenia), patients returned to the hospital or day hospital for further workup and care. Likewise, patients returned to the hospital or day hospital for certain routine procedures, such as intravenous methotrexate given as part of graft-versus-host disease prophylaxis or first blood transfusion to ensure there were no reactions. Transplant outcomes were monitored by the medical team throughout the patient's care and confirmed by a clinical research nurse or specialist by chart review. Stool samples, to assess changes in the gut microbiome, were collected at baseline and weekly for the first four weeks, at day 60, 100, and day 180. Samples will undergo 16s rRNA sequencing to identify the taxonomic groups of bacteria present in the gut.
Results: Twenty-two patients received home HCT (Table 1). This included 6 allos and 16 autos. Ages ranged from 34-63 years for allos and 46-74 years for autos. In both groups, 2/3 or more of patients had a baseline Karnofsky Performance Status of 70 or 80. Patients in the allo group spent 72% of their days entirely at home, while patients in the auto group spent 52% of their days at home. The main reason for returning to the hospital or day hospital were febrile neutropenia (4 allos and 9 autos). Aside from CMV reactivation (3 of 6 allos, 50%), only 2 allos (33%) and 2 autos (13%) developed bloodstream infections. Three allos developed GVHD; interestingly, these were the three patients that spent the most time in the hospital/day hospital even prior to Day 30 (median 23 days vs. 11 days), even prior to development of GVHD. There was one case of treatment-related mortality (GVHD) in the entire cohort. Overall, patients and their caregivers endorsed the program, providing numerous expressions of appreciation and gratitude on exit interviews, and quality of life was well-preserved as assessed by FACT-BMT: median scores for autos stayed the same when comparing baseline (median 113) to day 30 (median 114) and increased on day 100 (median 124).
Discussion: Our results suggest that home HCT is safe and feasible. Despite including mostly older adults with suboptimal performance status, patients did quite well at home. They were able to maintain their quality of life and had low rates of infectious complications. Though patients did have to return to the hospital or day hospital at various times during transplant, keeping patients out of the hospital for even half the duration of transplant could have tremendous cost savings that would offset the increased staffing and travel required for house calls. Studies of the gut microbiome are pending to test the hypothesis that home HCT will preserve the gut microbiome, thereby preventing GVHD. In addition, a randomized phase 2 study of home vs. standard transplant for allogeneic HCT is currently in progress.

Disclosures
Sung: Novartis: Research Funding; Merck: Research Funding; Cellective: Research Funding. Gasparetto: Janssen, BMS, Celgene: Consultancy; Janssen, BMS, Celgene: Other: Travel, accommodations, or other expenses paid or reimbursed; Celgene: Research Funding; Janssen, BMS, Celgene, Takeda: Honoraria. Rizzieri: Shire: Research Funding; Erytech: Research Funding.