Long-term follow-up study of porcine anti-human thymocyte immunoglobulin therapy combined with cyclosporine for severe aplastic anemia

Immunosuppressive therapy with antithymocyte immunoglobulin (ATG) and cyclosporine A is the first treatment option for severe aplastic anemia (SAA) patients without transplantation. Horse ATG is not marketed in China. Because the price of porcine ATG (pATG) is only about one-third of the price of rabbit ATG (rATG), long-term follow-up studies of pATG's efficacy will help provide valuable insights into the treatment of SAA. Retrospective studies were performed to analyze the clinical information of 102 SAA patients treated with pATG and cyclosporine A from 1999 to 2014 in Peking Union Medical College Hospital. The median age was 29 years old (range 12-72). Median follow-up time was 59.6 months (0.2-176.8). The overall response rate was 74.5% (CR 42.1%, PR 32.4%). The recurrence rate was 9.9%. The mortality rate was 16.7%. The median survival time has not been reached, and the 5-year survival rate was 81.8%. Other hematologic abnormalities were observed in 7.8% of patients, including symptomatic PNH, MDS, and AML. Multivariate analysis revealed there was no significant effect on survival by factors such as gender, age, severity of disease, treatment time, and PNH clone (P > 0.05). These data have indicated pATG therapy combined with cyclosporine A has significant long-term efficacy and high overall survival in SAA.