Disclosures: Robert Hauser, MD, MBA, FAAN: Merz (Products/Services: Yes) (Consultant/Advisory Board)

Objective: To assess the impact of different injection schedules of incobotulinumtoxinA on patient-reported outcomes in cervical dystonia (CD).

Design: The study was a phase IV, open-label, randomized, study (CD Flex; NCT01486264) comparing 2 incobotulinumtoxinA injection intervals subjects with CD.Setting : This was a multicenter study with 43 sites in the US.Participants : Subjects who are responsive to botulinum toxin (≥2 prior successful injections), but report waning of acceptable clinical benefit at < 10 weeks.

Interventions: IncobotulinumtoxinA was injected in 8 total treatment cycles over a period of 2 years using two different schedules (short-flex [N&#3f142]: 8±2 weeks; long-flex [N&#3f140]: 14±2 weeks).

Main Outcome Measures: Patient-reported outcomes included satisfaction (10-point scale), patient-reported global response (9-point Likert scale), and the CD impact profile (CDIP-58). Additional endpoints included a physician-assessed global response and a clinical global impression of severity. All endpoints were assessed 4 weeks after injection 8.

Results: Subject satisfaction was significantly improved vs study baseline over 8 cycles in the short-flex group (mean change=1.2 points, P=0.0007), but not in the long-flex group. A significant improvement was also observed in the short-flex group in the physician-assessed global impression of severity 4 weeks after injection 8. Most domains of the CDIP-58 analysis (pain/discomfort, sleep, annoyance, mood) demonstrated numerical trends favoring the short-flex group. At 4 weeks post-injection 8, a similar distribution of scores was observed for both groups on the subject-rated global response and physician-rated global response, with no relevant differences between groups. No differences in safety profile were noted.Conclusions: Subjects with shorter incobotulinumtoxinA injection intervals reported improved satisfaction after 8 injections. Trends favoring short-flex were observed in both the CDIP-58 analysis and physician-rated clinical global impression of severity. Overall, evidence suggests that individualizing injection intervals to treat CD may successfully improve patient-reported outcomes without compromising safety.

Level of Evidence: Level I

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/treatment-of-cervical-dystonia-using-shorter-incobotulinumtoxina-injection-intervals-improves-patient-reported-outcomes-in-those-with-inadequate-benefits-from-standard-intervals/