NEW YORK (Reuters Health) – The long-term survival of children with severe aplastic anemia who respond to immunosuppressive therapy with antithymocyte globulin and cyclosporine is “excellent, at about 90%,” based on a retrospective study conducted by researchers from the National Heart, Lung and Blood Institute, Bethesda, Maryland.

Moreover, they’ve found that three out of four children with severe aplastic anemia will respond to this therapy.

Immunosuppressive therapy “remains a good alternative” to hematopoietic stem cell transplantation (HSCT) in pediatric patients who lack an HLA-matched sibling donor and “should be offered as initial therapy” before HSCT from an unrelated donor, Dr. Phillip Scheinberg and colleagues report in the December issue of the Journal of Pediatrics.

Among 77 children treated with a horse antithymocyte globulin plus cyclosporine-based regimen between 1989 and 2006, the overall response rate at 6 months was 74% (57 of 77 children), they report. Thirty-five percent had a complete response and 65% had a partial response. “All of the children achieved transfusion independence,” the clinicians note.

The cumulative incidence of relapse at 10 years was 33%, and the median time to relapse was 558 days. The cumulative incidence of evolution to myelodysplasia after immunosuppressive therapy was 8.5% and “all three events occurred in the partial responders.”

Thirteen children died (17%). Four deaths occurred within the 3 months of immunosuppressive therapy in patients who had pretreatment absolute neutrophil counts less than 100 per microliters. The other nine deaths occurred more than 6 months after initiation of immunosuppressive therapy. “The median time to death was 570 days,” the investigators report.

Dr. Scheinberg and colleagues also report that the overall survival rate at 10 years for the entire cohort was 80%, whereas long-term survival in children who responded to immunosuppressive therapy was 89%.

Summing up, Dr. Scheinberg and colleagues conclude that “despite advances in alternative donor HSCT, prospective studies to date have been small, optimal conditioning remains undefined, and follow-up has been relatively short.”

“Therefore, in view of the high response and survival rate in children treated with immunosuppressive therapy, we recommend that immunosuppressive be offered as initial treatment in all children with severe aplastic anemia who lack a matched sibling donor.”

Reference:
J Pediatr 2008;153:814-819.