Subcutaneous Alemtuzumab May Be Useful in the Treatment of Steroid-Refractory Acute Graft-Versus-Host Disease.

Background: Acute graft-versus-host disease (GvHD) is mediated by activated T lymphocytes. Alemtuzumab is an unconjugated, humanized IgG1 kappa monoclonal antibody which targets the CD52 antigen on T lymphocytes and other cells and has been used successfully in conditioning regimens for allogeneic transplantation to remove donor T cells so as to prevent GvHD.

Patients and methods: Eighteen patients with steroid-refractory acute GvHD ≥ grade II were analyzed to evaluate the safety and efficacy of alemtuzumab. The patients received subcutaneous alemtuzumab 10 mg daily on days 1–5. The proportion of patients with grade II, III and IV were eight, eight and two, respectively. The main organ involved was the liver in four, gut in five, skin and liver in three, and skin and gut in three patients.

Results: Fifteen out of 18 patients (83%) responded to alemtuzumab with 6 (33%) complete and 9 (50%) partial responses. All three unresponsive patients died of GvHD. Ten of 15 responders are alive at a median follow-up of 9 months (range 2–23) after alemtuzumab, with limited, extensive and no signs of chronic GvHD in 1, 4, and 5 patients, respectively. Fourteen patients (78%) developed some kind of infection; eleven of them developed cytomegalovirus reactivation. All patients tolerated alemtuzumab with minimal side effects; grade 3 neutropenia and thrombocytopenia were seen in six and four patients, respectively.

Conclusions: Alemtuzumab is a well tolerated agent and has a beneficial effect in the treatment of steroid-refractory acute GvHD. Infections are common and anti-infective prophylaxis is mandatory.