title: Immunogenicity and long-term efficacy of botulinum toxin type B in the treatment of cervical dystonia:  report of 4 prospective, multicenter trials.
abstract: OBJECTIVE
  Therapeutic botulinum toxins are antigenic proteins with the potential to produce antibodies (Abs). It is, however, unclear whether Abs to Myobloc® (rimabotulinumtoxinB, botulinum toxin type B, BoNT-B) impact the efficacy and safety of BoNT-B treatment of cervical dystonia (CD). The objective was to determine if Abs to BoNT-B impact the efficacy or safety of long-term BoNT-B treatment of CD.
  
  
  METHODS
  Four separate prospective clinical trials, with a combined total of 1134 subjects evaluable for immunogenicity over total treatment durations of up to 6+ years, were conducted studying the efficacy, safety, and immunogenicity of BoNT-B treatment of CD. Botulinum toxin type B injections were administered approximately every 3 months. Efficacy was assessed using the Toronto Western Spasmodic Torticollis Rating Scale-Total Score, the Subject Global Assessment, or the Treatment Assessment Scale. The presence of Abs to BoNT-B was assessed using the mouse neutralizing antibody (MNA) assay. Cross-sectional and longitudinal statistical analyses were performed to compare efficacy by MNA status at each time point and over time in Ab-positive individuals before and after seroconversion. Safety was assessed by summarizing adverse events by Ab status.
  
  
  RESULTS
  Long-term efficacy was observed with multiple treatments of BoNT-B. Across all 4 studies, there was no correlation between MNA status and rates of clinical response, study withdrawal, or safety profile.
  
  
  CONCLUSIONS
  Botulinum toxin type B is effective and safe in the repeat, long-term treatment of CD. The presence of Abs to BoNT-B as detected by the MNA assay does not have any meaningful clinical impact or correlation.
authors.affiliation: US WorldMeds, LLC, Louisville, KY 40207, USA. RChinnapongse@usworldmeds.com
authors.forename: Robert B
authors.initials: RB
authors.lastname: Chinnapongse
authors.forename: Mark F
authors.initials: MF
authors.lastname: Lew
authors.forename: Joaquim J
authors.initials: JJ
authors.lastname: Ferreira
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Gullo
authors.forename: Paul R
authors.initials: PR
authors.lastname: Nemeth
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001905:Botulinum Toxins / Q000008:administration & dosage* / Q000276:immunology*; D019274:Botulinum Toxins, Type A; D003430:Cross-Sectional Studies; D004311:Double-Blind Method; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D011446:Prospective Studies; D013997:Time Factors; D014103:Torticollis / Q000188:drug therapy* / Q000453:epidemiology / Q000276:immunology*; D016896:Treatment Outcome
chemical_list: C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A