Corticosteroid-Free Primary Treatment of Chronic Extensive Graft-versus-Host Disease Incorporating Rituximab

Abstract

Chronic graft-versus-host disease (cGVHD) is a significant determinant of overall outcome and quality of life in survivors of allogeneic hematopoietic cell transplantation. Standard initial therapy of cGVHD is based on prolonged use of corticosteroids and a calcineurin inhibitor and has not changed for over 3 decades, despite limited efficacy and long-term toxicity. Rituximab is an attractive agent for the upfront treatment of cGVHD because of its favorable toxicity profile, efficacy in steroid-refractory cGVHD, and ability to serve as a steroid-sparing agent in autoimmune diseases. We hypothesized that a corticosteroid-free regimen incorporating rituximab would result in improved outcomes when used for the initial treatment of cGVHD. Twenty-five patients (median age, 56 years; range, 29 to 77) with extensive cGVHD were enrolled on a prospective phase II trial. Enrollment was limited to patients with first onset extensive cGVHD requiring systemic immunosuppression and without residual or concurrent acute graft-versus-host disease. cGVHD was classified as de novo, interrupted, and progressive in 12, 11, and 2 patients, respectively. cGVHD severity (National Institutes of Health grade) was mild, moderate, and severe in 3, 14, and 8 patients, respectively. All patients received rituximab 375 mg/m2 × 4 weekly doses, then 1 dose every 3 months × 4 doses, in addition to mycophenolate mofetil and either tacrolimus or sirolimus. No other systemic immunosuppression was permitted, and only a short-course of steroids (≤4 weeks) was allowed at physician discretion; otherwise, treatment was deemed a failure and patients were treated off study. Twenty-two of 25 patients (88%) responded to treatment. Of the 22 responding patients, the median time to maximum response was 161 days (range, 35 to 300 days) with maximum response being complete in 21 of 22 patients and partial in 1 patient. Excluding the 3 patients taken off study for treatment failure, corticosteroids were used sparingly, with only 2 patients receiving any steroids for a median of 15 days (range, 13 to 18 days). Immunosuppression was discontinued in 17 of 22 evaluable patients (77%) with a median time to discontinuation of 300 days (range, 138 to 488 days). After immunosuppression discontinuation, cGVHD did recur in 7 patients after a median of 166 days (range, 21 to 393 days), requiring reinstitution of systemic immunosuppression (estimated cGVHD recurrence rate of 37%). With a median follow-up of 27 months, estimated 2-year overall survival is 82%. This regimen utilizing rituximab in the initial therapy of cGVHD is effective and avoids the use of corticosteroids in the majority of patients. In permitting early discontinuation of immunosuppression while obviating the need for prolonged exposure to systemic corticosteroids, this regimen may result in reduced treatment-related morbidity and mortality associated with cGVHD and its treatment.