Treatment of severe aplastic anaemia with combined immunosuppression: anti‐thymocyte globulin, ciclosporin and mycophenolate mofetil

Summary Severe aplastic anaemia (SAA) can be successfully treated with immunosuppressive therapies or haematopoietic stem cell transplantation (HSCT). Response rates with horse anti‐thymocyte globulin (h‐ATG) plus ciclosporin (CsA) are about 60–70%, and robust responders have an excellent long‐term survival. We introduced a third immunosuppressive agent to standard h‐ATG/CsA, mycophenolate mofetil (MMF), in an attempt to improve the response rate and survival, and to decrease the relapse rate and clonal evolution to myelodysplasia. A total of 104 consecutive patients with SAA were treated with h‐ATG/CsA/MMF between May 1999 and June 2003 at the National Institutes of Health Clinical Center. The overall response rate at 6 months was 62%, with 24 (37% of responders) patients relapsing at a median of 389 d from ATG. Nine patients showed evidence of clonal evolution following ATG. After a median follow up of 42 months, the median survival among responders was not reached and among non‐responders was 58 months. Over half of the relapses occurred during MMF administration. Despite a strong theoretical rationale for its use, MMF did not result in the improvement of response or relapse rates when compared with historical standard h‐ATG/CsA.