Treatment of Steroid-refractory Chronic Graft-versus-host Disease with Imatinib: Real-life Experience of the Spanish Group of Hematopoietic Transplantation (GETH)

Treatment of steroid-refractory chronic graft-versus-host disease (cGVHD) is a challenge. Here, we describe a retrospective analysis of 66 patients with steroid-refractory cGVHD treated with imatinib (starting dose of 100 mg in 70% of patients; maximum dose of 100-200 mg in 74%). Most patients had multi-organ involvement (≥2 organs, 83%), with the most affected being skin (85%), oral mucosa (55%), eyes (42%), and lungs (33%). The overall response rate was 41% (21 partial and three complete responses). The organ with the best response rate was the skin (46%), followed by gastrointestinal tract (43%), liver (41%), the oral mucosa (36%), eyes (29%), and lungs (18%). Imatinib led to steroid tapering in 17/38 patients. Twenty-five (38%) patients experienced imatinib-related adverse events, comprising extra-hematologic toxicity (n = 24, 36%) and hematologic toxicity (n = 6, 9%). No cases of grade 4-5 toxicity were reported. The main causes of imatinib discontinuation were treatment failure (52%) and toxicity (9%). After a median follow-up of 41 months, the 3-year overall survival was 81%, with no difference between imatinib responders and non-responders. These real-life results show that imatinib is safe and has moderate efficacy in patients with heavily pre-treated cutaneous sclerotic cGVHD; however, activity against lung cGVHD is very limited.