Rapamycin for refractory acute graft-versus-host disease

Area of Science:

• Immunology
• Hematology
• Oncology

Background:

• Rapamycin (mTOR inhibitor) has immunosuppressive and antineoplastic properties.
• Steroid-refractory acute graft-versus-host disease (GVHD) is a major post-transplant complication with limited treatment options.
• This study retrospectively evaluated rapamycin for acute GVHD refractory to standard treatments.

Purpose of the Study:

• To assess the efficacy and safety of rapamycin in patients with steroid-refractory acute GVHD.
• To evaluate patient outcomes, including remission rates, survival, and adverse events.
• To provide a rationale for future prospective studies on rapamycin in GVHD management.

Main Methods:

• Retrospective, single-center study of 22 patients treated with rapamycin for acute GVHD.
• Patients received rapamycin for acute GVHD refractory to at least one prior treatment line.
• Analysis included efficacy (remission), tolerance (adverse events), and overall survival.

Main Results:

• Rapamycin achieved rapid and sustained complete remission in 72% of heavily pretreated patients.
• Cytopenias were common but manageable; thrombotic microangiopathy occurred in 36% when combined with calcineurin inhibitors.
• Overall survival was 41% at 13 months median follow-up; prior high-dose steroid pulse treatment correlated with worse outcomes.

Conclusions:

• Rapamycin demonstrates encouraging efficacy as a second- or third-line agent for steroid-refractory acute GVHD.
• Despite limitations of a small, heterogeneous patient group, results support further investigation.
• Infectious complications were the primary cause of mortality, highlighting the need for careful monitoring.