Multicenter observational study of abobotulinumtoxinA neurotoxin in cervical dystonia: The ANCHOR-CD registry.

BACKGROUND: The ANCHOR-CD prospective observational registry study evaluated the effectiveness of abobotulinumtoxinA in adult idiopathic cervical dystonia (CD) in clinical practice.

METHODS: Adults with CD were eligible. Treating physicians determined abobotulinumtoxinA dose and treatment interval. The primary endpoint was patient response rate (Toronto Western Spasmodic Torticollis Rating Scale [TWSTRS] score reduction≥25% and Patient Global Impression of Change [PGIC] score of +2 or +3 at Week 4 of Cycle 1).

RESULTS: 350 patients enrolled (75% women; mean age 59±13.6years; 27.4% botulinum neurotoxin-naive) and 347 received at least 1 treatment. The median abobotulinumtoxinA dose for Cycle 1 was 500 Units. At Week 4, the responder rate was 30.6% (n=304) and the TWSTRS total score decreased 27.4% from baseline. PGIC of at least "Much improved" was documented in 43.6% of patients and maintained in Cycles 2 through 4 (43.3%, 48.9%, and 52.8%, respectively). A total of 39 adverse events (31 study drug-related) were reported in 17 patients (5%); the most common were dysphagia (n=6), muscle weakness (n=4), and neck pain (n=3).

CONCLUSION: This study confirmed the beneficial effect of abobotulinumtoxinA on CD in routine clinical practice as measured by improvements in TWSTRS and PGIC. No new safety concerns were identified.