title: A phase II study of BTI-322, a monoclonal anti-CD2 antibody, for treatment of steroid-resistant acute graft-versus-host disease.
abstract: BTI-322, a rat monoclonal IgG2b directed against the CD2 antigen on T cells and natural killer (NK) cells, blocks primary and memory alloantigen proliferative responses in vitro. We have evaluated the pharmacokinetics and safety of BTI-322 during treatment of 20 transplant recipients with steroid-refractory acute graft-versus-host disease (GVHD). Treatment consisted of BTI-322 by intravenous (IV) bolus or 30-minute infusion at approximately 0.1 mg/kg/d for 10 days in addition to continuing high-dose steroids and tacrolimus or cyclosporine. Pharmacokinetic sampling was performed in 10 patients; the t1/2 +/- SE was 9.1 +/- 1.3 hours, the Cmax was 2,549 +/- 291 ng/mL, the Vd was 3.97 +/- 0.95 L, and the Vd/kg was 0. 05 +/- 0.01 L/kg. Ten patients experienced transient dyspnea sometimes accompanied by nausea, vomiting, diarrhea, and tachycardia shortly after the initial bolus dose of drug, but serious drug-related adverse events were not seen during the remainder of the infusions. At the end of treatment (day 11), there were six patients with complete responses and five with a reduction in grade of GVHD for a total response rate of 55% (95% confidence interval [CI], 32% to 77%). Antibodies targeting CD2 may be active in the treatment of acute GVHD, and evaluation of a humanized form of BTI-322 is warranted.
authors.affiliation: The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA. donnap@bcm.tmc.edu
authors.forename: D
authors.initials: D
authors.lastname: Przepiorka
authors.forename: G L
authors.initials: GL
authors.lastname: Phillips
authors.forename: V
authors.initials: V
authors.lastname: Ratanatharathorn
authors.forename: M
authors.initials: M
authors.lastname: Cottler-Fox
authors.forename: L H
authors.initials: LH
authors.lastname: Sehn
authors.forename: J H
authors.initials: JH
authors.lastname: Antin
authors.forename: D
authors.initials: D
authors.lastname: LeBherz
authors.forename: M
authors.initials: M
authors.lastname: Awwad
authors.forename: J
authors.initials: J
authors.lastname: Hope
authors.forename: J B
authors.initials: JB
authors.lastname: McClain
mesh_terms: D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D016026:Bone Marrow Transplantation / Q000009:adverse effects*; D018801:CD2 Antigens / Q000276:immunology; D004351:Drug Resistance; D005260:Female; D006086:Graft vs Host Disease / Q000188:drug therapy* / Q000276:immunology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008297:Male; D008875:Middle Aged; D051381:Rats; D013256:Steroids / Q000494:pharmacology; D014184:Transplantation, Homologous
chemical_list: D000911:Antibodies, Monoclonal; D018801:CD2 Antigens; C105249:LO-CD2a; D013256:Steroids