title: Stability of monoclonal antibodies, Lym-1 and ChL6, and 2IT-BAD-Lym-1 immunoconjugate with ultra freezer storage.
abstract: Use of a single lot of monoclonal antibody (MoAb) or immunoconjugate for clinical studies provides efficiency of scale and consistent characteristics for MoAb-based pharmaceuticals. Lym-1, an anti-lymphoma mouse IgG2 alpha chimeric L6 (ChL6), an anti-adenocarcinoma mouse IgG2 alpha-human IgG1 chimera, and the immunoconjugate 2IT-BAD-Lym-1 were examined for stability following storage.
  
  
  METHODS
  Lym-1, ChL6, and 2IT-BAD-Lym-1 were aliquotted with filtration and stored at -70 degrees C for up to 8.5 years. 2IT-BAD-Lym-1 stored for 6.3 years (lot A) was compared to freshly prepared 2IT-BAD-Lym-1 (lot B). MoAbs were thawed and examined yearly by gel filtration high performance liquid chromatography (HPLC), polyacrylamide gel electrophoresis (PAGE), cellulose acetate electrophoresis (CAE), and Scatchard analysis of antigen binding. 2IT-BAD-Lym-1 was evaluated by HPLC, CAE, and radioimmunoassay. To assure the in vivo significance of the in vitro studies, 2IT-BAD-Lym-1 lots A and B were labeled with 111In and their pharmacokinetics in BALB/c mice were compared.
  
  
  RESULTS
  Lym-1 demonstrated stability over 8.5 years, providing the following ranges of data over the interval: 98-100% chemical purity (HPLC), 96-100% monomeric fraction (CAE), 8.18-8.46 antigen binding pKa (Scatchard). Similar results were obtained for ChL6 for 7.4 years. HPLC and PAGE of Lym-1 and ChL6 have not changed from original manufacturer specifications, and both MoAbs remain sterile and apyrogenic. No significant differences between 2IT-BAD-Lym-1 lots A and B were observed by in vitro evaluation or pharmacokinetics in mice.
  
  
  CONCLUSIONS
  Lym-1, ChL6, and 2IT-BAD-Lym-1 as manufactured and stored for 8.5, 7.4, and 6.3 years, respectively, demonstrated retention of structural and functional integrity.
authors.affiliation: Department of Internal Medicine, University of California Davis Medical Center, Sacramento 95616, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Kukis
authors.forename: S J
authors.initials: SJ
authors.lastname: DeNardo
authors.forename: S L
authors.initials: SL
authors.lastname: Mills
authors.forename: S
authors.initials: S
authors.lastname: Shen
authors.forename: R T
authors.initials: RT
authors.lastname: O'Donnell
authors.forename: G L
authors.initials: GL
authors.lastname: DeNardo
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000493:pharmacokinetics*; D058846:Antibodies, Monoclonal, Murine-Derived; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D005260:Female; D005615:Freezing; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D014018:Tissue Distribution
chemical_list: C410508:2IT-BAD-Lym-1 monoclonal antibody; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; C106337:ChL6 monoclonal antibody; C410509:Lym-1 monoclonal antibody