A phase III, randomized, multi-center, double blind, placebo controlled study of safety and efficacy of lofexidine for relief of symptoms in individuals undergoing inpatient opioid withdrawal.

BACKGROUND: Lofexidine is an alpha-2-adrenergic receptor agonist approved in the United Kingdom (UK) for the treatment of opioid withdrawal symptoms. Lofexidine has demonstrated better efficacy than placebo for reducing opioid withdrawal symptoms in patients undergoing opioid withdrawal with less reported hypotension than clonidine. METHODS: Designed as an FDA registration trial, this 8-day, randomized, double-blind, placebo-controlled, parallel-group study in 264 patients dependent on short-acting opioids evaluated the efficacy of lofexidine hydrochloride in reducing withdrawal symptoms in patients undergoing opioid withdrawal. The primary efficacy measures were SOWS-Gossop on Day 3 and time-to-dropout. Secondary endpoints included the proportion of participants who were completers; area under the 5-day SOWS-Gossop - time curve (i.e., AUC1-5), and daily mean SOWS-Gossop, OOWS-Handelsman, MCGI (subject and rater), and VAS-E scores. Participants received lofexidine HCl 3.2mg daily in four divided doses or matching placebo on Days 1-5, followed by 2days of placebo. RESULTS: Lofexidine significantly decreased mean Day 3 SOWS scores compared to placebo, 6.32 versus 8.67, respectively, p=0.0212. Fewer lofexidine patients were early terminators compared to placebo (59 versus 80, respectively); and non-completers in the lofexidine group remained in the study longer than those assigned to placebo (p=0.0034). Secondary endpoints consistently favored lofexidine. Lofexidine was well tolerated in this trial. CONCLUSION: Lofexidine significantly decreased SOWS scores compared to placebo and demonstrated better retention rates in participants undergoing opioid withdrawal. Lofexidine potentially offers a useful non-opioid alternative to treat opioid withdrawal symptoms.

Immunogenicity and long-term efficacy of botulinum toxin type B in the treatment of cervical dystonia: report of 4 prospective, multicenter trials.

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.