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Dysport (AbobotulinumtoxinA) Wins FDA Nod for Treatment of Upper-Limb Spasticity in Adults
The FDA has approved the supplemental biologics license application for Dysport (abobotulinumtoxinA, Ipsen) for the treatment of upper-limb spasticity in adults after submission of the dossier in September 2014.
Dysport is now indicated for the treatment of upper-limb spasticity in adult patients, to decrease the severity of increased muscle tone in elbow flexors, wrist flexors, and finger flexors. Clinical improvement may be expected 1 week after administration of the drug. Most patients in clinical studies were treated for between 12 and 16 weeks, and some patients showed a response for as long as 20 weeks.
Dysport is an injectable form of botulinum toxin type A (BoNT-A), which is isolated and purified from Clostridium BoNT-A bacteria. It is supplied as a lyophilized powder. The drug was previously approved in the U.S. for the treatment of adults with cervical dystonia, and for the treatment of adults with moderate-to-severe glabellar lines.
The FDA’s recent approval was based on data from a clinical development program that included studies conducted in more than 600 patients. In a pivotal phase III, double-blind, randomized, placebo-controlled trial, 238 adult patients with upper-limb spasticity were treated with Dysport for up to 1 year. The study compared the efficacy of Dysport (n = 159) with that of placebo (n = 79) in hemiparetic patients after stroke or brain trauma. The trial’s co-primary endpoints were the improvement of muscle tone in the treated upper limb, as measured by the Modified Ashworth Scale (MAS), compared with placebo and the clinical benefit for patients, as assessed by the Physician Global Assessment (PGA) score, compared with placebo at week 4. The study was followed by an open-label phase in which patients received Dysport for up to five treatment cycles to assess its long-term safety.
Subjects treated with Dysport demonstrated statistically significant improvement in muscle tone, as measured by the MAS, and a significantly higher physician-rated clinical benefit, as measured by the PGA, compared with placebo at week 4 (P ≤ 0.05). Also at week 4, both doses of Dysport (500 U and 1,000 U) significantly reduced muscle tone, as measured by the MAS, in all primary target muscle groups, which included elbow, wrist, and finger muscles, with approximately 75% of patients responding to Dysport.
The most common treatment-associated adverse events included urinary-tract infection, nasopharyngitis, muscular weakness, musculoskeletal pain, dizziness, falls, and depression. The rates of serious adverse events were identical (3.7%) among the three treatment groups.
It has been estimated that 1.8 million adult Americans experience spasticity, which in the upper arm can cause muscle stiffness, flexing, spasms, twitching, and pain. The condition most commonly occurs after a stroke but can also result from other injuries to the central nervous system, such as a spinal cord injury or a traumatic brain injury, or it can occur in adults with multiple sclerosis or cerebral palsy. Symptoms may not appear until months or even years after the stroke or injury, and can include bent elbows or wrists, and hands clenched into fists.
Source: Pipeline Review; July 16, 2015.