Abatacept to Treat Steroid Refractory Chronic Graft Versus Host Disease (cGVHD)

The study will follow a standard 3+3 design with two escalating doses of abatacept to determine the maximum tolerated dose (MTD): 3 mg/kg (dose level 1) and 10 mg/kg (dose level 2). Dose-limiting toxicities (DLTs) are defined as any Grade 3 or 4 toxicities judged to be probably or definitely related to abatacept.