Objective: To investigate the efficacy and safety of repeated treatment with incobotulinum toxin A (botulinum neurotoxin type A free from complexing proteins; NT 201) in post-stroke upper limb spasticity.
Patients and design: After completing a double-blind, placebo- controlled, multicentre study (up to 20 weeks), 145 patients received up to 5 additional sets of NT 201 injections for an open-label extension period of up to 69 weeks.
Methods: Upper limb muscle groups were treated as clinically indicated; injection intervals were ≥ 12 weeks. Outcome was assessed 4 weeks after each injection session and at the end of the study.
Results: Muscle tone (flexors of wrist, elbow, finger, and thumb, and forearm pronators) improved throughout the study (response rate: up to 80.6%, p < 0.0001, Ashworth Scale). Continuous and significant improvements were also observed in disability (p < 0.05, Disability Assessment Scale). The majority of investigators, patients and caregivers rated NT 201 efficacy as very good or good (56-84%). Adverse events considered treatment-related occurred in 11% of patients. Formation of neutralizing antibodies was not observed in any patient after repeated treatments.
Conclusion: Treatment with NT 201 showed sustained improvements in muscle tone and functionality (median dose 400 units) over a study duration of up to 89 weeks, and was well tolerated during repeated treatments for post-stroke upper limb spasticity.