title: Pharmacokinetics of alemtuzumab used for in vivo and in vitro T-cell depletion in allogeneic transplantations: relevance for early adoptive immunotherapy and infectious complications.
abstract: Persistence of alemtuzumab at lympholytic concentrations after reduced-intensity conditioning allogeneic stem cell transplantations (RITs) could impair immune reconstitution and reduce donor T-cell-mediated graft-versus-leukemia/lymphoma (GVL) effects, derived from the graft or subsequent adoptive immunotherapy. We have studied the pharmacokinetics of alemtuzumab in 2 different groups: RIT (100 mg alemtuzumab in vivo over 5 days) and myeloablative allografts (20 mg alemtuzumab added in vitro to the stem cells prior to return). Alemtuzumab concentrations in RIT patients were in excess of that required to kill infused donor CD52+ cells at the time of transplantation and remained at potentially lympholytic levels (> 0.1 microg/mL) for approximately 56 days after transplantation, 26 days longer than for the myeloablative group. Total lymphocyte counts were significantly lower in the RIT group persisting beyond 6 months after transplantation (P =.005), and median absolute CD4 counts higher than 200 x 106/L were delayed until 9 months after transplantation.
authors.affiliation: Department of Haematology, University College Hospital, 98 Chenies Mews, London WC1E 6HX, UK. emma.morris@ic.ac.uk
authors.forename: Emma C
authors.initials: EC
authors.lastname: Morris
authors.forename: Peppy
authors.initials: P
authors.lastname: Rebello
authors.forename: Kirsty J
authors.initials: KJ
authors.lastname: Thomson
authors.forename: Karl S
authors.initials: KS
authors.lastname: Peggs
authors.forename: Charalampia
authors.initials: C
authors.lastname: Kyriakou
authors.forename: Anthony H
authors.initials: AH
authors.lastname: Goldstone
authors.forename: Stephen
authors.initials: S
authors.lastname: Mackinnon
authors.forename: Geoff
authors.initials: G
authors.lastname: Hale
mesh_terms: D000293:Adolescent; D000328:Adult; D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics* / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D005260:Female; D019337:Hematologic Neoplasms / Q000150:complications / Q000628:therapy; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007107:Immune System / Q000187:drug effects; D016219:Immunotherapy, Adoptive; D018655:Lymphocyte Count; D008212:Lymphocyte Depletion / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009894:Opportunistic Infections; D010599:Pharmacokinetics; D019172:Transplantation Conditioning / Q000379:methods; D014184:Transplantation, Homologous
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D000970:Antineoplastic Agents; D000074323:Alemtuzumab