Acute GVHD (aGVHD) is a major cause of morbidity and mortality in hematopoietic allograft recipients. The best therapy for patients failing to respond, or not tolerating, systemic glucocorticoids remains undefined. We evaluated the efficacy of sirolimus in 34 patients, median age of 49 (23-67) years, with steroid-refractory (n=31) or steroid-intolerant (n=3) aGVHD. aGVHD was diagnosed at a median of 34 (7-1042) days post allografting, and confirmed by biopsy in all cases. Initial aGVHD treatment consisted of prednisone up to 2 mg/kg. Sirolimus was initiated at a median of 9 (1-255) days after glucocorticoid initiation. A sirolimus loading dose was administered to 19 (56%) of 34 patients, median 6 (3-8) mg, followed by maintenance of 1-2 mg/day to target therapeutic trough levels between 4 and 12 ng/ml. Overall response rate was 76%. Fifteen (44%) of 34 patients achieved CR, defined as complete resolution of aGVHD sustained for at least 1 month, after sirolimus initiation without additional immunosuppressive agents. CR was achieved in 11 (42%) of 31 steroid-refractory and 2 (67%) of 3 steroid-intolerant patients. Median OS after initiation of sirolimus was 5.6 months, and 1-year OS was 44% (95% CI: 27-60%). Sirolimus is effective in controlling steroid-refractory aGVHD.

2235 Poster Board II-212 Acute graft-versus-host disease (aGVHD) remains the major cause of morbidity and mortality in allogeneic hematopoietic cell transplant recipients. There is no consensus in regards to the best therapy for patients who fail to respond to, or do not tolerate, systemic glucocorticoids. We evaluate the efficacy of sirolimus in 34 pts, median age of 49 (23-67) years, with steroid-refractory (N=31) or steroid-intolerant (N=3) aGVHD. The diagnosis of aGVHD was established at a median of 34 (7-1042) days after transplantation, and confirmed by biopsy in all cases. Initial treatment of aGVHD consisted of prednisone up to 2 mg/kg. Sirolimus was initiated at a median of 9 (1-255) days after glucocorticoid initiation. A loading dose of sirolimus was administered to 19 (56%) of 34 pts, median 6 (3-8) mg, followed by maintenance therapy of 1-2 mg per day with doses adjusted to target therapeutic trough levels between 4 and 12 ng/ml; therapeutic levels were achieved in all cases. The overall response rate was 76%. Fifteen (44%) of the 34 pts achieved a CR after sirolimus initiation and without requiring additional immune suppressive agents. CR was achieved in 11/31 (42%) steroid-refractory patients, and in 2/3 (67%) steroid-intolerant patients. The median overall survival (OS) after initiation of sirolimus was 5.6 months, and one year OS was 44% (95% C.I. 27%-60%). Maximum decrease in dose of steroids over 12 weeks following sirolimus was a median of 50% (range 0-100%). Fourteen (42%) of 33 pts reached a dose < 20 mg of prednisone at a median of 4 months (95% CI: 3.5-13.5) after initiation of sirolimus. Seven (21%) of 34 pts were free from steroids after a median of 20 months (95% CI: 9.2-20.0) after initiation of sirolimus. Two pts were shown to be successfully liberated from all immunosuppressive agents without recurrent GVHD at 2.7 and 7.1 months after initiation of sirolimus, respectively. These data indicate the sirolimus is effective in controlling steroid-refractory aGVHD. Further studies are needed to determine the most appropriate timing for sirolimus after transplantation, whether prophylaxis, primary or secondary GVHD therapy. Disclosures: Off Label Use: Sirolimus for graft-versus-host disease.