Therapy of steroid-refractory acute GVHD with CD52 antibody alemtuzumab is effective

Abstract

The efficacy and safety of CD52 antibody alemtuzumab to treat severe acute GVHD in 18 consecutive patients refractory to standard high-dose corticosteroid therapy is reported. Patients (age range 13-68 years) had developed acute GVHD grade III and IV with gut and/or liver involvement after stem cell transplantation from family donors (n= 7) or HLA-matched unrelated donors (n=11), including five donors with one or two HLA mismatches. Initially, in three patients, start doses of alemtuzumab in the range of 70-80 mg were applied and repeated after 3 to 4 weeks. Impressive responses were seen, but virus reactivation and bacterial infections were frequent. In an attempt to reduce this complication, the next nine patients received a reduced starting dose of 20-33 mg, and the last six patients received 3-13 mg repeated every 2-3 weeks. Seventeen of 18 patients responded to alemtuzumab, six patients are alive with a median follow-up of 108 weeks. Chronic GVHD was observed frequently. Although pronounced lymphocyte depletion requiring close monitoring for signs of infections seems inevitable for efficacy, alemtuzumab given in moderate doses has a substantial activity not only in intestinal but also in severe acute GVHD of the liver.