Immunosuppressive therapy for acquired severe aplastic anemia (SAA): a prospective comparison of four different...

This study was designed to investigate four different immunosuppressive therapy (IST) regimens as treatment of acquired severe aplastic anemia (SAA).

142 consecutive SAA patients were randomized to receive one of the following IST regimens: equine anti-human thymocyte immunoglobulin (E-ATG) alone (IST regimen I); E-ATG and cyclosporine A (CSA) (IST regimen II); E-ATG, CSA plus recombinant human granulocyte-macrophage colony-stimulating factor (rhuGM-CSF) and rhu erythropoietin (rhuEPO) (IST regimen III); or rabbit ATG (ATG-F), CSA, rhuGM-CSF, and rhuEPO (IST regimen IV). No repeated courses of E-ATG or ATG-F were given for nonresponders. All patients also received stanozolol or testosteron propionate.

The overall response rate to IST regimen I was 58%. The response to IST regimen II (79%) was significantly higher (p = 0.04), more rapid and complete than after IST regimen I. The response rate to IST regimen IV (53%) was significantly lower than that of IST regimen III (73%, p = 0.039). The additional use of growth factors did not reduce early deaths and did not accelerate hematopoietic recovery after IST. Of the 142 patients enrolled in this trial, 92 (65%) are alive at a median follow-up time of 102 months (range, 54-166 months). The 5-year actuarial survival for IST regimens I, II, III, and IV was 58%, 81%, 80%, and 66%, respectively.

The combination of E-ATG and CSA remains the best combination for the treatment of SAA patients, producing a survival advantage at 5 years. The addition of growth factors did not improve these results. Rabbit ATG-F appeared less effective than E-ATG.