Visilizumab is a humanized anti-CD3 monoclonal antibody characterized by a mutated IgG2 isotype, lack of binding to Fc␥-receptors, and ability to induce apoptosis selectively in activated T cells. To test pharmacokinetics, safety, and immunosuppressive activity of visilizumab, 17 patients with glucocorticoid-refractory acute graft-versus-host disease (GVHD) were enrolled in a phase 1 study. Six patients were given 7 doses of visilizumab (

Telomerase activity in human breast cancers is associated with a more aggressive tumor phenotype in patients.