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: Robert B Chinnapongse, Mark F Lew, Joaquim J Ferreira, Kristen L Gullo, Paul R Nemeth, Yuxin Zhang
• Journal: Clinical neuropharmacology (Clin Neuropharmacol) 2012 Sep-Oct Vol. 35 Issue 5 Pg. 215-23 ISSN: 1537-162X [Electronic] United States
• PMID: 22932474 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• rimabotulinumtoxinB
• Botulinum Toxins
• Botulinum Toxins, Type A

Topics

• Animals
• Botulinum Toxins (administration & dosage, immunology)
• Botulinum Toxins, Type A
• Cross-Sectional Studies
• Double-Blind Method
• Humans
• Longitudinal Studies
• Male
• Mice
• Mice, Inbred ICR
• Prospective Studies
• Time Factors
• Torticollis (drug therapy, epidemiology, immunology)
• Treatment Outcome