Placebo Controlled Double Blind Study of Acetyl Hexapeptide-8 in Treatment of Blepharospasm
Placebo Controlled Double Blind Study of Acetyl Hexapeptide-8 in Treatment of Blepharospasm
Background:
- Blepharospasm is caused by excessive contraction of the muscles that close the eye. One treatment is botulinum neurotoxin (BoNT), which works by weakening those muscles. Like BoNT, acetyl hexapeptide-8 (AH-8) works to weaken the muscles, but is available as a skin cream. AH-8 is the active ingredient in a number of cosmetic creams used to treat wrinkles. Researchers thought that AH-8 cream could be used to treat blepharospasm, but the original dose studied was not very effective. They want to try a higher dose of AH-8 in a cream to see if it can be a more effective treatment.
Objectives:
- To see if AH-8 cream can improve the symptoms of blepharospasm.
Eligibility:
- Individuals at least 18 years of age who have blepharospasm that is severe enough to require treatment.
Design:
OBJECTIVE:
Test the efficacy of topical AH-8 in blepharospasm treatment.
DESIGN:
This is a randomized, double blind, placebo-controlled study, phase II single center clinical trial. Patients with primary blepharospasm at least 4 months off BoNT therapy with no benefit from last BoNT injection by history and self assesment will be included. We will use 3 study arms placebo and 2 different doses (as concentrations of the AH-8 active substance in the topical preparation). An extension phase is planned after the initial phase.
The patients will have a baseline screening visit, including measurement of the outcome variables, then begin the study intervention. They will have 2 subsequent visits at month 1 and month 2. After this visit, the patients who do not have significant benefit and wish to have an alternative therapy (GROUP 1) will receive BoNT injections according to best practice standards. These patients will then be assessed 1 month later (peak effect of BoNT therapy) and the effect will be compared with the AH-8 effect. The patients who have significant benefit (GROUP 2) will continue therapy for another 4 months (total of 6 months), and will have another assessment at that point. Afterwards the patients will be offered BoNT injections according to best practice standards, similar to Group 1 above, and another assessment will be made one month later (month 7) to compare the effects with AH-8 effects.
OUTCOME MEASURES:
Primary outcome variable: the Jankovic Blepharospasm Rating Scale at month 2.
Secondary outcome variables:
Non-parametric comparison (Wilcoxon Mann-Whitney test) of the primary and secondary variables before and after the intervention will be used for statistical analysis. Additional multivariate analysis will explore the influence of other factors (age, gender, disease duration).
Interventions and Duration
Twice daily application of active substance or placebo. Two active substance concentrations, 0.025% and 0.05% AH-8 will be used.
Each subject will be in the study a total of at least 3 months, followed by additional up to 4 months in the second phase for the group 2 patients.
Sample Size and Population
There will be 8 patients per arm, for a total study population of 24. The power calculation for a power of 80%, for a 2-tailed alpha of 0.05, to be able to detect a change of 2 points on the JBRS requires 8 patients per arm. This calculation was based on independent calculation for each dose of the active agent against placebo.
The subjects included will be patients with primary blepharospasm, not currently treated with BoNT (de novo diagnosed patients), but who subjectively express a wish for treatment intervention, with at least one year history from symptom onset, without perceived active change in symptoms by history. Patients with blepharospasm as part of a generalized dystonia or due to a different neurologic condition will be excluded.
Randomization and blinding to be performed by the NIH research pharmacy.
INCLUSION CRITERIA:
Primary blepharospasm diagnosed or confirmed by a Movement Disorders Neurologist, confirmed at the initial visit by a study investigator.
Individuals off BoNT therapy for at least 4 months will be eligible for this study.
EXCLUSION CRITERIA: