Rabbit antithymocyte globulin (r‐ATG) plus cyclosporine and granulocyte colony stimulating factor is an effective treatment for aplastic anaemia patients unresponsive to a first course of intensive immunosuppressive therapy

Abstract

About 30% of patients with severe aplastic anaemia (SAA) unresponsive to one course of immunosuppressive (IS) therapy with antithymocyte or antilymphocyte globulin can achieve complete or partial remission after a second IS treatment. Among various second‐line treatments, rabbit ATG (r‐ATG) could represent a safe and effective alternative to horse ALG (h‐ALG). In a multicentre study, 30 patients with SAA (17 males and 13 females, median age 21 years, range 2–67) not responding to a first course with h‐ALG plus cyclosporin (CyA) and granulocyte colony stimulating factor (G‐CSF), were given a second course using r‐ATG (3.5 mg/kg/d for 5 d), CyA (5 mg/kg orally from day 1 to 180) and G‐CSF (5 μg/kg subcutaneously from day 1 to 90). The median interval between first and second treatment was 151 d (range 58–361 d). No relevant side‐effects were observed, but one patient died early during treatment because of sepsis. Overall response, defined as transfusion independence, was achieved in 23/30 (77%) patients after a median time of 95 d (range 14–377). Nine patients (30%) achieved complete remission (neutrophils 2.0 × 109/l, haemoglobin 11 g/dl and platelets 100 × 109/l). The overall survival rate was 93% with a median follow‐up of 914 d (range 121–2278). So far, no patient has relapsed. Female gender was significantly associated with a poorer likelihood to respond (P = 0.0006). These data suggest that r‐ATG is a safe and effective alternative to h‐ALG for SAA patients unresponsive to first‐line IS treatment.