Sirolimus immunosuppression for graft-versus-host disease prophylaxis and therapy: an update

Purpose of review Sirolimus is being used increasingly as an immunosuppressant in allogeneic hematopoietic stem cell transplantation. This article reviews recent results in sirolimus-based graft-versus-host disease (GVHD) prophylaxis, as well as outcomes using sirolimus for established acute and chronic GVHD. Recent findings In uncontrolled experiments, sirolimus provides good control of steroid-resistant acute or chronic GVHD. Similarly, the addition of sirolimus to GVHD prophylaxis regimens appears to reduce the rate of acute GVHD in the myeloablative and reduced-intensity settings, when used in matched, related, and unrelated donor transplantation. The use of sirolimus in haploidentical transplantation is now being explored as well. Summary Sirolimus should be considered for use in steroid-resistant acute and chronic GVHD. Sirolimus appears promising as primary prophylaxis for GVHD prevention. Randomized trials are currently being performed to determine whether sirolimus-based immunosuppression is superior to traditional GVHD prophylaxis.