Comparison of Korean Botulinum Toxin Type A Versus Botox in the Treatment of Essential Blepharospasm
Condition: Blepharospasm
MeSH terms: Blepharospasm
Study type: Interventional
Phase: Phase 3

Summary: 
      To compare the efficacy and safety of Korean botulinum toxin A (KbtxA, Pacific
      Pharmaceuticals, Korea) against Botox in the treatment of essential blepharospasm, we
      performed a double-blinded, randomized, comparative trial comparing KbtxA and Botox for
      treatment of blepharospasm in 60 patients of the intention to treat population and 52
      patients (26 patients from each group) of the per protocol population. The improvement of
      severity of spasm (SS) at 4 weeks post-injection as a primary efficacy outcome, qualifying
      non inferiority to the control group, Changes in eyelid closure force (CF) and functional
      visual status (FVS) after injection for secondary efficacy outcomes, and adverse effects for
      safety evaluation. Improvement of SS was noted in 90.3% of the KbtxA group and 86.2% of the
      Botox group. There were no significant differences between treatment groups in the changes of
      CF and FVS after injection (p>0.05). Adverse effects developed in 16.1% of the KbtxA group
      and 27.6% of the Botox group, but no serious adverse events were found in either group. KbtxA
      was not inferior to Botox in treatment efficacy and was clinically safe with no serious
      adverse effects when used to treat essential blepharospasm.
    

Detailed description: 
      Severity of spasm was graded clinically from grade 0 to 4. Primary efficacy outcome was
      assessed as the number (%) of patients with improved SS of more than 1 score at 4 weeks
      post-injection. Secondary efficacy outcome measures included the change in scores from
      baseline on the SS, closing force of eyelids, and functional visual status at 4 weeks
      post-injection. The duration of action (days), the time interval between injection and the
      moment that the patient felt the need for retreatment were also assessed as secondary
      efficacy outcomes.

      The number (%) of patients with improvement of SS (primary efficacy outcome) and the change
      in scores from baseline at 4 weeks post-injection on the severity of spasm, closing force of
      eyelids, and functional visual status scores were not different between the KbtxA and Botox
      groups in the analysis of both the ITT and PP populations. Also, the duration of action was
      similar following KbtxA and Botox injections (two sample t-test, p=0.835). For the
      non-inferiority trial on primary efficacy outcome, KbtxA was not inferior to Botox in either
      the ITT or PP populations, as the lower limit of the 95% confidence interval (-1.76% for ITT,
      -1.64% for PP) was over the -15% threshold.
    

Intervention name(s): Korean Botulinum toxin type A (KbtxA) and Botox injection
Intervention type(s): Drug
Intervention description(s): Each vial of Botox and KbtxA contained 100 U of BTX-A in a sterile vacuum-derived form without preservatives. Each vial of KbtxA was identical to the placebo (Botox) vial, and all vials were reconstituted with 2.0 mL of 0.9% sterile nonpreserved saline solution to a final dilution of 5 U /0.1 mL. The dose of BTX-A per injection site was 2.5 U to 5 U, and the location, number of injection sites. Using a 30-gauge needle, injections were angled away from the center of lid to reduce the risk of spread into the levator muscle. Injection sites include the upper medial and lateral eyelid margins, lower lateral lid margins, and above the eyebrow.
Other intervention name(s): arm1 ; Meditoxin or Neuronox
Intervention MeSH terms: Botulinum Toxins; Botulinum Toxins, Type A; abobotulinumtoxinA
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Botulinum Toxin Type A; Blepharospasm