Horsies and bunnies: A comparison of antithymocyte globulin in allogeneic stem cell transplant.
Lu C, Neme K, Mikulandric N, Grycki M, Pelland D, Farhan S, Janakiraman N, Peres E, Vogel V, and Szandzik E. Horsies and bunnies: A comparison of antithymocyte globulin in allogeneic stem cell transplant. Biol Blood Marrow Transplant 2018; 24(3):S287-S288.
Biol Blood Marrow Transplant
: Graft versus host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplant (HSCT). In vivo T-cell depletion includes antithymocyte globulin (ATG) such as ATG-Horse or ATG-Rabbit used in combination with a calcineurin inhibitor and low dose methotrexate to decrease the incidence of GVHD in HSCT recipients. This method of broad T-cell depletion has decreased the incidence, severity and treatment refractoriness of chronic GVHD. Objective: The goal of this study is to describe the impact of transitioning from ATG-Horse to ATG-Rabbit at Henry Ford Hospital located in Detroit, Michigan. The primary endpoint is the incidence of chronic GVHD after switching products. Secondary endpoints include: incidence of acute GVHD, cumulative incidence of CMV reactivation, average length of stay, incidence of hypersensitivity reactions, and overall incidence of infection. A final cost analysis was performed to highlight financial savings. Methods: This retrospective non-inferiority study evaluated the clinical outcomes of unrelated HSCT patients who received ATG to prevent GVHD. Patients from January 2005 to December 2015 were included in the study if they were adults greater than 18 years old who received an allogeneic unrelated HSCT (peripheral or bone marrow) with ATGHorse or ATG-Rabbit. Results: There were no statistically significant differences in incidence of acute and chronic GVHD between both ATGRabbit and ATG-Horse groups. The one-sided confidence interval was .21, which exceeds the pre-specified noninferiority margin of .15, thus non-inferiority cannot be concluded. Overall length of stage was statistically significantly shorter in ATG-Rabbit group by 3 days. Total cost savings from 2011-2016 with the switch of ATG agents was $570,036.18, or $6,552.14 per patient. Conclusion: Despite not meeting the hypothesis that ATGRabbit is non-inferior to ATG-Horse, there is still benefit in ease of administration and decreased length of stay, which validates the continual use of ATG-Rabbit in allogeneic unrelated HSCT patients.