title: Per cent of patients with chronic migraine who responded per onabotulinumtoxinA treatment cycle: PREEMPT.
abstract: OBJECTIVE
  The approved use of onabotulinumtoxinA for prophylaxis of headaches in patients with chronic migraine (CM) involves treatment every 12 weeks. It is currently unknown whether patients who fail to respond to the first onabotulinumtoxinA treatment cycle will respond to subsequent treatment cycles. To help inform decisions about treating non-responders, we examined the probability of treatment cycle 1 non-responders responding in cycle 2, and cycle 1 and 2 non-responders responding in cycle 3.
  
  
  METHODS
  Pooled PREEMPT data (two studies: a 24-week, 2-cycle, double-blind, randomised (1:1), placebo-controlled, parallel-group phase, followed by a 32-week, 3-cycle, open-label phase) evaluated onabotulinumtoxinA (155-195 U) for prophylaxis of headaches in persons with CM (≥15 days/month with headache ≥4 h/day). End points of interest included the proportion of study patients who first achieved a ≥50% reduction in headache days, moderate/severe headache days, total cumulative hours of headache on headache days, or a ≥5-point improvement in Headache Impact Test (HIT)-6. For treatment cycle 1, all eligible participants were included. For subsequent cycles, responders in a previous cycle were no longer considered first responders.
  
  
  RESULTS
  Among onabotulinumtoxinA-treated patients (n=688) 49.3% had a ≥50% reduction in headache-day frequency during treatment cycle 1, with 11.3% and 10.3% of patients first responding during cycles 2 and 3, respectively. 54.2%, 11.6% and 7.4% of patients first responded with a ≥50% reduction in cumulative hours of headache, and 56.3%, 14.5% and 7.7% of patients first responded with a ≥5-point improvement in total HIT-6 during treatment cycles 1, 2 and 3, respectively.
  
  
  CONCLUSIONS
  A meaningful proportion of patients with CM treated with onabotulinumtoxinA who did not respond to the first treatment cycle responded in the second and third cycles of treatment.
  
  
  BACKGROUND
  NCT00156910, NCT00168428.
authors.affiliation: Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Silberstein
authors.affiliation: Department of Neurology, Mayo Clinic Arizona, Phoenix, Arizona, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Dodick
authors.affiliation: Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA.
authors.forename: Sheena K
authors.initials: SK
authors.lastname: Aurora
authors.affiliation: Department of Neurology and Stroke Center, University of Essen, Essen, Germany.
authors.forename: Hans-Christoph
authors.initials: HC
authors.lastname: Diener
authors.affiliation: Allergan, Inc., Irvine, California, USA.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: DeGryse
authors.affiliation: Department of Neurology and the Montefiore Headache Center, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Lipton
authors.affiliation: Clinical Development Neurology & Pain, Allergan, Inc., Irvine, California, USA.
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Turkel
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D002908:Chronic Disease; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000188:drug therapy / Q000517:prevention & control*; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
keywords: BOTULINUM TOXIN; HEADACHE; MIGRAINE