Characterization of Collaborative Practice Agreements (CPA) Held By Hematopoietic Cell Transplant (HCT) Pharmacists

Abstract

practice change was implemented in 2012 to include ATG as part of the conditioning regimen for recipients of MRD HCT. Methods: Patients at least 18 years old who received HCT from an HLA 8/8 MRD for a hematologic malignancy were included. The control group was comprised of patients who did not receive ATG and received HCT between . The ATG group was comprised of patients who received rabbit ATG (Thymoglobulin) 3mg/kg in divided doses from day -3 to day -1, and received HCT between Jan 1, 2012 to June 30, 2014. The primary endpoint is incidence of grade II-IV aGVHD occurring up to 100 days post-HCT. Secondary endpoints include immunosuppression free survival (IFS), overall survival (OS), relapse, nonrelapse mortality (NRM), and infection rates. Continuous measures were compared using two-sample independent t-tests or Wilcoxon signed-rank test and categorical measures with chisquare tests. Time to event outcomes were measured using the log-rank test and the Grey's test to account for competing events. Results: There were 37 patients in the ATG group and 24 patients in the control group. Median age in both groups was 51 years. Baseline characteristics were well matched in the ATG vs. control groups: male sex (49% vs 58%), peripheral blood stem cell source (97% vs 96%), myeloablative conditioning (89% vs 100%), and GVHD prophylaxis with cyclosporine and methotrexate (84% vs 75%). All patients engrafted. Grade II-IV and grade III-IV aGVHD occurred in 19% and 29% (p¼0.35) and 11% and 21% (p¼0.29) of patients in the ATG and control groups, respectively. At day 100 post-HCT there was no difference in cytomegalovirus reactivation (41% vs 33%, p¼0.57) or Epstein-Barr virus reactivation (24% vs 8%, p¼0.17), but there was a trend towards an increase in BK cystitis requiring treatment (16% vs 0%, p¼0.07) in the ATG vs control group. At day 180 post-HCT there was no difference in OS (86% vs 79%, p¼0.49), relapse (16% vs 8%, p¼0.46), or NRM (14% vs 17%, p¼0.72) between the ATG and control groups. IFS at day 180 post-HCT was greater in the ATG vs control group (65% vs 38%, p¼0.04) (Figure 1). Conclusion: The addition of ATG to the conditioning regimen in MRD HCT did not significantly reduce the incidence of aGVHD. However, more patients receiving ATG were off immunosuppression at 180 days post-HCT compared with those not receiving ATG, possibly reflecting a reduction in chronic GVHD. Our findings demonstrate the need for randomized trials to evaluate the overall impact of ATG on outcomes of MRD HCT.