Anti-CD52 monoclonal antibody, clone YTH66.9HL

Alemtuzumab, a monoclonal antibody targeting CD52 that causes lymphocyte apoptosis, is a form of advanced immunosuppression that is currently used as a therapy for refractory acute cellular rejection and chronic lung allograft dysfunction in lung transplant recipients (1-3). Side effects of alemtuzumab include bone marrow suppression, infection, and malignancy. Whether alemtuzumab can be safely used in allograft recipients that have an increased propensity for bone marrow suppression due to telomeropathies is unknown. In a retrospective case series, we report outcomes associated with alemtuzumab in three lung allograft recipients with short telomere lengths, comparing endpoints such as leukopenia, transfusion needs, infection, hospitalization and survival to those of 17 patients without known telomeropathies that received alemtuzumab. We show that the use of alemtuzumab in lung transplant recipients with short telomeres is safe, though is associated with an increased incidence of neutropenia, thrombocytopenia and anemia requiring packed red blood cell transfusions. Alemtuzumab appears to be an acceptable advanced immunosuppressive therapy in patients with telomeropathies, though given the design and scope of this study, the actual clinical effect needs further evaluation in larger trials.

To evaluate the feasibility and clinical efficacy of the combination of alemtuzumab with dose-adjusted etoposide/cyclophosphamide/doxorubicin/vincristine/prednisone (DA-EPOCH) as upfront therapy for untreated aggressive T and NK cell lymphomas, a phase 1/2 trial was conducted. Thirty patients were treated with the study regimen, consisting of alemtuzumab on day 1 of a 21day cycle with standard dosing of DA-EPOCH for 6-8 cycles. Alemtuzumab 30mg IV was used for the phase 2 component. Of 30 treated patients, 17 had a complete response (CR) and eight had a partial response (83.3% overall response rate). The median overall survival and progression-free survival were 20.2 and 6.6months, respectively. There were five treatment-related deaths on study mainly due to infectious complications, including one case each of disseminated toxoplasmosis and pneumonia and two cases of sepsis. Alemtuzumab with DA-EPOCH is of limited clinical utility due to unacceptable toxicity, despite the high rate of CR.