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

About 30% of patients with severe aplastic anaemia (SAA) unresponsive to on e course of immunosuppressive (IS) therapy with antithymocyte or antilympho cyte globulin can achieve complete or partial remission after a second IS t reatment. Among various second-line treatments, rabbit ATG (r-ATG) could re present a safe and effective alternative to horse ALG (h-ALG). In a multice ntre study, 30 patients with SAA (17 males and 13 females, median age 21 ye ars, range 2-67) not responding to a first course with h-ALG plus cyclospor in (CyA) and granulocyte colony stimulating factor (G-CSF), were given a se cond 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 mu g/kg subcutaneously from day 1 to 90). The media n interval between first and second treatment was 151 d (range 58-361 d), N o relevant side-effects were observed, but one patient died early during tr eatment because of sepsis, Overall response, defined as transfusion indepen dence, was achieved in 23/30 (77%) patients after a median time of 95 d (ra nge 14-377). Nine patients (30%) achieved complete remission (neutrophils g reater than or equal to 2.0 x 10(9)/l, haemoglobin greater than or equal to 11 g/dl and platelets greater than or equal to 100 x 10(9)/l). The overall survival rate was 93% with a median follow-up of 914d (range 121-2278). So far, no patient has relapsed. Female gender was significantly associated w ith 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 unrespons ive to first-line IS treatment.