Comparison of porcine ALG and rabbit ATG on outcomes of HLA-haploidentical hematopoietic stem cell transplantation for patients with acquired aplastic anemia

Objective To evaluate the efficacy and safety of P-ALG (porcine anti-lymphocyte globulin) and R-ATG (rabbit anti-thymocyte globulin) in the conditioning regime for patients with acquired aplastic anemia who underwent HLA-haploidentical hematopoietic stem cell transplantation (halpo-HSCT). Methods A total of 91 patients with acquired aplastic anemia who received haplo-HSCT at our center between January 2014 and December 2020 were retrospectively reviewed. Twenty-eight patients were in the P-ALG group while sixty-three patients were in the R-ATG group. Results The median time was 11 versus 13 days (P = 0.294) for myeloid engraftment and 12.5 versus 15 days (P = 0.465) for platelet engraftment in the P-ALG and R-ATG groups, respectively. There were no significant difference in 5-year overall survival (74.83% +/- 8.24% vs 72.29% +/- 6.26%, P = 0.830), GVHD-free, failure-free survival (71.05% +/- 8.65% vs 62.71% +/- 6.22%, P = 0.662), failure-free survival (74.83% +/- 8.24% vs 66.09% +/- 5.84%, P = 0.647) and transplantation-related mortality (25.17% +/- 8.24% vs 26.29% +/- 6.22%, P = 0.708) between the two groups. The incidence of aGVHD (acute graft versus host disease) (65.39% +/- 9.33% vs 62.71% +/- 6.30%, P = 0.653), II-IV aGVHD (38.46% +/- 9.54% vs 35.64% +/- 6.24%, P = 0.695), III-IV aGVHD (19.23% +/- 7.73% vs 10.53% +/- 4.07%, P = 0.291), cGVHD (chronic graft versus host disease) (22.22% +/- 12.25% vs 22.31% +/- 6.30%, P = 0.915), and moderate to severe cGVHD (5.56% +/- 5.40% vs 9.28% +/- 4.46%, P = 0.993) were not significantly different. Similar outcomes were observed between the P-ALG and R-ATG groups for severe bacterial infection (17.9% vs 25.4%, P = 0.431), invasive fungal diseases (3.6% vs 9.5%, P = 0.577) and graft rejection (0% vs 9.5%, P = 0.218). However, the incidence of cytomegalovirus infection and Epstein-Barr virus infection was significantly lower in the P-ALG group (46.4% vs 71.4%, P = 0.022; 3.6% vs 25.4%, P = 0.014). Conclusion The efficacy and safety of P-ALG were similar with R-ATG in the setting of haplo-HSCT for patients with acquired aplastic anemia patients. P-ALG could be an alternative for R-ATG.

Automated summary

A retrospective study found that P-ALG and R-ATG have similar efficacy and safety in patients with acquired aplastic anemia undergoing haplo-HSCT. P-ALG could be an alternative option to R-ATG.