Early onset of effect of onabotulinumtoxinA for chronic migraine treatment: Analysis of PREEMPT data.

BACKGROUND: The Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) trials demonstrated efficacy/tolerability of onabotulinumtoxinA for headache prevention in adults with chronic migraine. This post hoc analysis assessed time of onset of onabotulinumtoxinA after the first treatment in total and responder populations and consistency weekly through five treatment cycles. METHODS: In the 24-week, double-blind, placebo-controlled phase of PREEMPT, individuals were randomized 1:1 to onabotulinumtoxinA (155-195 U) or placebo every 12 weeks for two cycles. The primary pooled efficacy variable was change in headache days per 28 days at week 24. We assessed change in headache and migraine/probable migraine (hereafter migraine) days/week compared with baseline week 4. RESULTS: Baseline mean (SD) headache days/week (week 4 of baseline) for onabotulinumtoxinA (n = 688) and placebo (n = 696) were similar (4.8 [1.6] vs. 4.8 [1.6] days/week, respectively), as were migraine days/week (4.6 [1.7] vs. 4.6 [1.7] days/week). The effect of onabotulinumtoxinA on change in headache and migraine days/week was significantly greater than placebo at week 1, persisting from week 3 after the first treatment (-1.6 [2.2] vs. -1.1 [2.2] headache days/week [ p < 0.001] and -1.6 [2.2] vs. -1.1 [2.2] migraine days/week [ p < 0.001]). Headache and migraine days decreased in onabotulinumtoxinA responders beginning 1 week after treatment 1. CONCLUSIONS: Treatment with onabotulinumtoxinA is associated with significant reductions in headache and migraine days/week at week 1, persisting after week 3, compared with placebo. Combined with earlier reports showing onabotulinumtoxinA treatment results in a persistent and progressive reduction in headache days over 56 weeks, it is suggested peak benefit may require multiple treatments. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT00156910 and NCT00168428.

The impact of onabotulinumtoxinA on severe headache days: PREEMPT 56-week pooled analysis.

BACKGROUND: OnabotulinumtoxinA has been shown to reduce headache-days among patients with chronic migraine (CM). The objective of this analysis was to determine whether onabotulinumtoxinA has an impact on headache-day severity in patients with CM among those patients who were deemed non-responders based on reduction in the frequency of headache days alone. METHODS: Data from the Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) clinical trial program (a 24-week, 2-treatment cycle, double-blind, randomized, placebo-controlled, parallel-group phase, followed by a 32-week, 3-treatment cycle, open-label phase) were pooled for analysis. Patients kept a daily diary to record headache severity on a 4-point scale (from none to severe), and a 6-domain Headache Impact Test (HIT-6) was used to determine the clinical impact of headaches. Analysis was undertaken to assess whether the subset of patients that were headache-day frequency non-responders at week 24 (patients with <50% reduction in headache-day frequency) experienced a reduction in headache severity whilst receiving onabotulinumtoxinA. RESULTS: For headache-day frequency non-responders, significant reductions in the number of severe headache days, average daily headache severity, pooled percentage of severe headache days and headache severity score were observed at week 24 for patients who had received onabotulinumtoxinA compared with those who had received placebo. The between-group differences were reduced and non-significant at week 56. Similarly, headache-day frequency non-responders receiving onabotulinumtoxinA were found to have an improvement in the clinical impact of headaches using results from the HIT-6. CONCLUSIONS: These results suggest that even those patients with CM who are deemed non-responders based on analysis of headache frequency alone experience clinically meaningful relief from headache intensity following treatment with onabotulinumtoxinA.

OnabotulinumtoxinA improves quality of life and reduces impact of chronic migraine over one year of treatment: Pooled results from the PREEMPT randomized clinical trial program.

BACKGROUND: Chronic migraine (CM) is associated with high impact and reduced health-related quality of life (HRQoL). METHODS: Patients with CM from PREEMPT (Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy) were randomized (1:1) to receive onabotulinumtoxinA or placebo for two 12-week cycles in the double-blind (DB) phase, followed by three 12-week cycles of open-label (OL) onabotulinumtoxinA (onabotulinumtoxinA/onabotulinumtoxinA (O/O) and placebo/onabotulinumtoxinA (P/O) groups, respectively). HRQoL endpoints were assessed over 56 weeks using the Headache Impact Test (HIT-6) and the Migraine-Specific Quality of Life Questionnaire (MSQ). HIT-6 score reductions ≥2.3 and ≥5 denoted between-group minimally important difference and within-patient clinically meaningful response, respectively. RESULTS: A total of 1236 participants (O/O, n = 607; P/O, n = 629) participated in both phases. The DB phase showed significantly reduced HIT-6 and MSQ for onabotulinumtoxinA versus placebo (all p < 0.001). The OL phase showed significantly reduced HIT-6 for O/O versus P/O at weeks 28, 36, and 48, but not 56. All three MSQ domains showed improved HRQoL relative to baseline, but only the role restrictive domain showed a significant difference between O/O and P/O at week 56. CONCLUSIONS: Benefits of onabotulinumtoxinA on HRQoL versus baseline persisted throughout the OL phase. Statistical superiority in favor of O/O was demonstrated for HIT-6 through 48 weeks and for MSQ (role restrictive) at 56 weeks.

Per cent of patients with chronic migraine who responded per onabotulinumtoxinA treatment cycle: PREEMPT.

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. TRIAL REGISTRATION NUMBER: NCT00156910, NCT00168428.

Validation of the Headache Impact Test (HIT-6) in patients with chronic migraine.

BACKGROUND: The Headache Impact Test (HIT)-6 was developed and has been validated in patients with various types of headache. The objective of this study was to report the psychometric properties of the HIT-6 among patients with chronic migraine. METHODS: Data came from two international, multicenter, randomized, double-blind, placebo-controlled clinical trials of chronic migraine patients (N = 1,384) undergoing prophylaxis therapy. Confirmatory factor analysis and differential item functioning (DIF) analysis were used to test the latent structure and cross-cultural comparability of the HIT-6. Reliability, construct validity, and responsiveness were assessed. Two sets of criterion groups were used: (1) 28-day headache frequency: <10, 10-14, and ≥15 days; (2) sample quartiles of the total cumulative hours of headache: <140, 140 to <280, 280 to <420, and ≥420 hours. Two sets of responsiveness categories were defined as reduction of <30%, 30% to <50%, or ≥50% in (1) number of headache days and (2) cumulative hours of headache. RESULTS: Measurement invariance tests supported the stability of the HIT-6 latent structure across studies. DIF analysis supported cross-cultural comparability. Good reliability was observed across studies (Cronbach's α: 0.75-0.92; intraclass correlation coefficient: 0.76-0.80). HIT-6 scores correlated strongly (-0.86 to -0.59) with scores of the Migraine-Specific Quality-of-Life Questionnaire. Analysis of variance indicated that HIT-6 scores discriminated across both types of criterion groups (P<0.001), across studies and time points. HIT-6 change scores were significantly higher in magnitude in groups experiencing greater improvement (P<0.001). CONCLUSION: All measurement properties were consistently verified across the two studies, supporting the validity of the HIT-6 among chronic migraine patients. TRIAL REGISTRATION: NCT00156910 and NCT00168428 on www.ClinicalTrials.gov.

OnabotulinumtoxinA for treatment of chronic migraine: pooled analyses of the 56-week PREEMPT clinical program.

OBJECTIVE: To evaluate safety and efficacy of onabotulinumtoxinA (BOTOX(®) ) as headache prophylaxis in adults with chronic migraine. BACKGROUND: Chronic migraine is a prevalent, disabling, and undertreated neurological disorder. OnabotulinumtoxinA is the only approved prophylactic therapy in this highly disabled patient population. DESIGN AND METHODS: Two phase III, 24-week, double-blind, parallel-group, placebo-controlled studies, followed by a 32-week, open-label, single-treatment, onabotulinumtoxinA phase, were conducted (January 23, 2006 to August 11, 2008). Qualified subjects were randomized (1:1) to injections of onabotulinumtoxinA (155-195 U) or placebo every 12 weeks for 5 cycles (double-blind: 2, open-label: 3). The pooled primary variable was mean change from baseline in frequency of headache days. Secondary variables included proportion of patients with severe Headache Impact Test-6 score (≥ 60) and mean changes from baseline in frequencies of migraine days, moderate/severe headache days, and migraine episodes; cumulative hours of headache on headache days; and acute headache medication intakes. The primary time point was week 24. Assessments for the open-label phase (all patients treated with onabotulinumtoxinA) compared double-blind treatment groups (onabotulinumtoxinA/onabotulinumtoxinA vs placebo/onabotulinumtoxinA) and are summarized to give a descriptive view of consistent study results, with inferences regarding statistical significance only examined for week 56. RESULTS: A total of 1384 patients were randomized to onabotulinumtoxinA (n = 688) or placebo (n = 696) in the double-blind phase; 607 (88.2%) onabotulinumtoxinA/onabotulinumtoxinA and 629 (90.4%) placebo/onabotulinumtoxinA patients continued into the open-label phase. OnabotulinumtoxinA/onabotulinumtoxinA treatment statistically significantly reduced headache-day frequency vs placebo/onabotulinumtoxinA in patients with chronic migraine at week 56 (-11.7 onabotulinumtoxinA/onabotulinumtoxinA, -10.8 placebo/onabotulinumtoxinA; P = .019). Statistically significant reductions also favored onabotulinumtoxinA/onabotulinumtoxinA for several secondary efficacy variables at week 56, including frequencies of migraine days (-11.2 onabotulinumtoxinA/onabotulinumtoxinA, -10.3 placebo/onabotulinumtoxinA; P = .018) and moderate/severe headache days (-10.7 onabotulinumtoxinA/onabotulinumtoxinA, -9.9 placebo/onabotulinumtoxinA; P = .027) and cumulative headache hours on headache days (-169.1 onabotulinumtoxinA/onabotulinumtoxinA, -145.7 placebo/onabotulinumtoxinA; P = .018). After the open-label phase (all treated with onabotulinumtoxinA), statistically significant within-group changes from baseline were observed for all efficacy variables. Most patients (72.6%) completed the open-label phase; few discontinued because of adverse events. No new safety or tolerability issues emerged. CONCLUSIONS: Repeated treatment with ≤ 5 cycles of onabotulinumtoxinA was effective, safe, and well tolerated in adults with chronic migraine.

OnabotulinumtoxinA for treatment of chronic migraine: pooled results from the double-blind, randomized, placebo-controlled phases of the PREEMPT clinical program.

OBJECTIVE: To assess the efficacy, safety, and tolerability of onabotulinumtoxinA (BOTOX) as headache prophylaxis in adults with chronic migraine. BACKGROUND: Chronic migraine is a prevalent, disabling, and undertreated neurological disorder. Few preventive treatments have been investigated and none is specifically indicated for chronic migraine. METHODS: The 2 multicenter, pivotal trials in the PREEMPT: Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy clinical program each included a 24-week randomized, double-blind phase followed by a 32-week open-label phase (ClinicalTrials.gov identifiers NCT00156910, NCT00168428). Qualified patients were randomized (1:1) to onabotulinumtoxinA (155-195 U) or placebo injections every 12 weeks. Study visits occurred every 4 weeks. These studies were identical in design (eg, inclusion/exclusion criteria, randomization, visits, double-blind phase, open-label phase, safety assessments, treatment), with the only exception being the designation of the primary and secondary endpoints. Therefore, the predefined pooling of the results was justified and performed to provide a complete overview of between-group differences in efficacy, safety, and tolerability that may not have been evident in individual studies. The primary endpoint for the pooled analysis was mean change from baseline in frequency of headache days at 24 weeks. Secondary endpoints were mean change from baseline to week 24 in frequency of migraine/probable migraine days, frequency of moderate/severe headache days, total cumulative hours of headache on headache days, frequency of headache episodes, frequency of migraine/probable migraine episodes, frequency of acute headache pain medication intakes, and the proportion of patients with severe (> or =60) Headache Impact Test-6 score at week 24. Results of the pooled analyses of the 2 PREEMPT double-blind phases are presented. RESULTS: A total of 1384 adults were randomized to onabotulinumtoxinA (n = 688) or placebo (n = 696). Pooled analyses demonstrated a large mean decrease from baseline in frequency of headache days, with statistically significant between-group differences favoring onabotulinumtoxinA over placebo at week 24 (-8.4 vs -6.6; P < .001) and at all other time points. Significant differences favoring onabotulinumtoxinA were also observed for all secondary efficacy variables at all time points, with the exception of frequency of acute headache pain medication intakes. Adverse events occurred in 62.4% of onabotulinumtoxinA patients and 51.7% of placebo patients. Most patients reported adverse events that were mild to moderate in severity and few discontinued (onabotulinumtoxinA, 3.8%; placebo, 1.2%) due to adverse events. No unexpected treatment-related adverse events were identified. CONCLUSIONS: The pooled PREEMPT results demonstrate that onabotulinumtoxinA is an effective prophylactic treatment for chronic migraine. OnabotulinumtoxinA resulted in significant improvements compared with placebo in multiple headache symptom measures, and significantly reduced headache-related disability and improved functioning, vitality, and overall health-related quality of life. Repeat treatments with onabotulinumtoxinA were safe and well tolerated.

The Impact of OnabotulinumtoxinA vs. Placebo on Efficacy Outcomes in Headache Day Responder and Nonresponder Patients with Chronic Migraine.

INTRODUCTION: The phase 3 PREEMPT trials demonstrated efficacy and tolerability of onabotulinumtoxinA for headache prevention in adults with chronic migraine. OnabotulinumtoxinA significantly reduced headache frequency from baseline vs. placebo at 24 weeks; however, this measure may not fully capture the benefits of treatment. We evaluated the impact of onabotulinumtoxinA on patient-reported outcomes according to headache responder status. METHODS: A post hoc analysis pooled 24-week data from the placebo-controlled, randomized, double-blind treatment phases of the PREEMPT trials. Patients were stratified by randomized treatment (onabotulinumtoxinA vs. placebo) and headache day responder status (responder vs. nonresponder). Headache day responders had a ≥ 50% headache day reduction from baseline measured at weeks 21-24. Outcomes evaluated were patient-reported reductions in moderate-to-severe headache days, Headache Impact Test, and Migraine-Specific Quality of Life Questionnaire. Missing values were estimated using a modified last-observation-carried-forward approach. RESULTS: In the pooled analysis population (N = 1384; onabotulinumtoxinA, n = 688; placebo, n = 696), headache day responder rates were 308/688 (45%) for onabotulinumtoxinA- and 238/696 (34%) for placebo-treated patients. At 24 weeks compared with baseline, onabotulinumtoxinA nonresponders showed significantly (all P < 0.01) greater mean (standard error) reductions vs. placebo nonresponders in moderate-to-severe headache days (- 3.5 [0.2] vs. - 2.4 [0.2]) and Headache Impact Test scores (- 2.3 [0.3] vs. - 0.8 [0.2]), and greater mean improvements in Migraine-Specific Quality of Life Questionnaire domains (Restrictive, 8.8 [1.0] vs. 2.9 [0.8]; Preventive, 6.0 [1.0] vs. 1.8 [0.8]; Emotional, 8.5 [1.3] vs. 2.8 [1.1]). Moderate-to-severe headache day and headache impact differences between nonresponder groups were evident at week 4 and sustained through week 24. CONCLUSIONS: Relative to placebo nonresponders, onabotulinumtoxinA nonresponders experienced significant reductions in moderate-to-severe headache days and disability and improvement in quality of life, implying that the full benefits of onabotulinumtoxinA are not captured by headache day reduction. TRIAL REGISTRATION: ClinicalTrials.gov identifiers, NCT00156910 (PREEMPT 1) and NCT00168428 (PREEMPT 2).

Benefits Beyond Headache Days With OnabotulinumtoxinA Treatment: A Pooled PREEMPT Analysis.

INTRODUCTION: The double-blind, phase 3 PREEMPT trials demonstrated the efficacy and tolerability of onabotulinumtoxinA for headache prevention in adults with chronic migraine. This post hoc analysis evaluated the effect of onabotulinumtoxinA on clinically meaningful changes in headache severity, headache-related impact, and quality of life. METHODS: Pooled, 24-week data were used to determine percentages of patients meeting responder criteria for the change in headache days (≥ 50% reduction in headache-day frequency), Headache Impact Test (HIT-6; ≥ 5-point improvement), MSQ Role Function-Restrictive (MSQ-RFR; ≥ 10.9-point improvement), and Average Daily Headache Severity (ADHS; ≥ 1-point improvement on a 4-point ordinal scale [0 = no pain, 3 = severe pain]). RESULTS: In the pooled analysis population (N = 1384; onabotulinumtoxinA, n = 688; placebo, n = 696), significantly more patients treated with onabotulinumtoxinA compared with placebo were responders on HIT-6 (40.8 vs. 25.3%), MSQ-RFR (59.0 vs. 40.2%), and ADHS (35.5 vs. 22.4%) measures, and achieved traditional ≥ 50% reduction in headache days (44.8 vs. 34.2%; all P < 0.001). At least one responder criterion was met by 72.1% and 56.6% of onabotulinumtoxinA- and placebo-treated patients, respectively; all four were met by 20.4% and 8.6%, respectively (P < 0.001). Linear regression analysis showed that approximately 20% of the variance in HIT-6 and MSQ-RFR improvement was explained by improvement in headache days. CONCLUSIONS: Treatment with onabotulinumtoxinA for 24 weeks was associated with clinically meaningful benefits beyond reduction in headache days; including reductions in headache severity and headache-related impact, and improved quality of life. While 45% of patients met responder criteria for monthly headache days, over 70% had clinically meaningful improvements on at least one outcome measure. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT00156910 (PREEMPT 1) and NCT00168428 (PREEMPT 2).

A series of three sequential, randomized, controlled studies of repeated treatments with botulinum toxin type A for migraine prophylaxis.

UNLABELLED: We examined the effects of multiple treatments with low doses of botulinum toxin type A (BoNTA; BOTOX(R), Allergan Inc., Irvine, CA) versus placebo for prophylaxis of episodic migraine. This was a series of 3 sequential, randomized, controlled studies of 418 patients with a history of 4 to 8 moderate to severe migraines per month. In study I, patients were randomized to treatment with placebo or BoNTA (7.5 U, 25 U, or 50 U) in predetermined fixed injection sites on the front and sides of the head only. In study II, patients continued to receive, or were randomized to, 2 consecutive treatments with 25 U or 50 U. In study III, patients were randomized to placebo or continuation of 25 U or 50 U. Injection cycles were each 4 months long. BoNTA and placebo produced comparable decreases from baseline in the frequency of migraines at each time point examined (P >or= .201). No consistent, statistically significant differences were observed for any efficacy variable. Adverse events were similar among the groups within each study. In these exploratory studies of episodic migraine patients, repeated injections of low doses of BoNTA into fixed frontal, temporal, and glabellar sites were not more effective than placebo. BoNTA was safe and well tolerated. PERSPECTIVE: Beneficial effects of BoNTA in the treatment of migraine have been reported, but positive results are not universal, possibly because the optimal patient population and regimen are not yet definitively established. This study explores the effects of multiple injections of low BoNTA doses into fixed sites for episodic migraine.

Botulinum toxin type A for the prophylactic treatment of chronic daily headache: a randomized, double-blind, placebo-controlled trial.

OBJECTIVES: To identify a treatment-responsive population for botulinum toxin type A (BoNTA) and to evaluate the safety and efficacy of 3 different doses of BoNTA as prophylactic treatment of chronic daily headache (CDH). PATIENTS AND METHODS: A randomized, double-blind, placebo-controlled study of BoNTA in patients with CDH was conducted from July 6, 2001, through November 7, 2003, at 28 North American study centers. Eligible patients were injected with BoNTA at 225 U, 150 U, 75 U, or placebo and returned for additional masked treatments at day 90 and day 180. Patients were assessed every 30 days for 9 months. The primary efficacy end point was the mean change from baseline in the frequency of headache-free days at day 180 for the placebo nonresponder group. RESULTS: For this study, 702 patients were enrolled and randomized. The primary efficacy end point was not met. Mean improvements from baseline at day 180 of 6.0, 7.9, 7.9, and 8.0 headache-free days per month were observed in the placebo nonresponder group treated with BoNTA at 225 U, 150 U, 75 U, or placebo, respectively (P=.44). An a priori-defined analysis of headache frequency revealed that BoNTA at 225 U or 150 U had significantly greater least squares mean changes from baseline than placebo at day 240 (-8.4, -8.6, and -6.4, respectively; P=.03 analysis of covariance). Only 27 of 702 patients (3.8%) withdrew from the study because of adverse events, which generally were transient and mild to moderate. CONCLUSIONS: Although the primary efficacy end point was not met, all groups responded to treatment. The 225 U and 150 U groups experienced a greater decrease in headache frequency than the placebo group at day 240. The placebo response was higher than expected. BoNTA was safe and well tolerated. Further study of BoNTA prophylactic treatment of CDH appears warranted.

Assessing clinically meaningful treatment effects in controlled trials: chronic migraine as an example.

UNLABELLED: In addition to headache, persons with chronic migraine (CM) experience multiple symptoms, both ictal and interictal, that may contribute to their suffering. Translating clinical trial results into practice requires assessment of the results' clinical meaningfulness. When examining treatment benefit in this disabled patient population, multiple headache-symptom measures should be considered to fully reflect clinical relevance. Currently, only onabotulinumtoxinA is approved specifically for headache prophylaxis in adults with CM. Topiramate is the only other therapeutic agent with double-blind, placebo-controlled evidence in this population. Herein we evaluate the clinical meaningfulness of onabotulinumtoxinA and topiramate as headache prophylaxis in CM by comparing primary endpoints from the placebo-controlled, double-blind phase of the Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) clinical program and the topiramate clinical trial (frequency of headache days [primary endpoint in PREEMPT; secondary in topiramate trial] and migraine/migrainous days [primary in topiramate trial, or "migraine/probable-migraine days"; secondary in PREEMPT]). Additionally, outcome measures such as responder rates, health-related quality of life, discontinuation rates, safety, and tolerability profiles are important clinical considerations. The clinical data indicate that statistically significant, clinically relevant treatment benefits exist for both onabotulinumtoxinA and topiramate. These data support these treatments as meaningful headache prophylaxis in adults with CM. PERSPECTIVE: CM is a chronic pain condition. We sought to determine the clinical relevance of recent trials in this disabled population. Clinical data indicate that statistically significant, clinically relevant treatment benefits exist for both onabotulinumtoxinA and topiramate, and support use of these treatments as meaningful headache prophylaxis in CM.

Development of onabotulinumtoxinA for chronic migraine.

Discovery of the neuromuscular effects of botulinum toxin began in the early 19th century and has continued to evolve. Currently, onabotulinumtoxinA is approved by the U.S. Food and Drug Administration for two cosmetic and eight medical indications, including chronic migraine (CM). CM is a disabling form of migraine characterized by ≥15 headache days monthly and is believed to result from neuronal hypersensitivity to proinflammatory mediators, upregulation of sensory receptors, and consequent maladaptive pain responses with peripheral and central sensitization. OnabotulinumtoxinA achieves migraine prophylaxis in CM through regulation of vesicular trafficking and exocytosis, inhibition of peripheral release of neuropeptides and inflammatory peptides, and reduced cell surface expression of certain ion channels and receptors. Clinically, efficacy of onabotulinumtoxinA for CM has been shown in two phase III, placebo-controlled trials (PREEMPT 1 and PREEMPT 2). OnabotulinumtoxinA significantly reduced the number of headache days per 28-day cycle relative to placebo at week 24 (change from baseline: -8.4 days for onabotulinumtoxinA versus -6.6 days for placebo; P < 0.001, pooled data). OnabotulinumtoxinA improved health-related quality of life and had an acceptable safety profile. OnabotulinumtoxinA is the only approved treatment specifically for CM prevention and represents a safe and effective therapeutic for chronic migraineurs.

OnabotulinumtoxinA for treatment of chronic migraine: PREEMPT 24-week pooled subgroup analysis of patients who had acute headache medication overuse at baseline.

Acute headache medication overuse (MO) is common in patients with chronic migraine (CM). We evaluated safety and efficacy of onabotulinumtoxinA as preventive treatment of headache in CM patients with baseline MO (CM+MO) in a planned secondary analysis from two similarly designed, randomized, placebo-controlled, parallel, Phase III trials. Patients were randomized to treatment groups (155-195 U of onabotulinumtoxinA or placebo) using MO (patient-reported and diary-captured frequency of intake) as a stratifying variable. Of 1384 patients, 65.3% (n=904) met MO criteria (onabotulinumtoxinA: n=445, placebo: n=459). For the CM+MO subgroup at Week 24, statistically significant between-treatment group mean changes from baseline favoring onabotulinumtoxinA versus placebo were observed for headache days (primary endpoint: -8.2 vs. -6.2; p<0.001) and other secondary endpoints: frequencies of migraine days (p<0.001), moderate/severe headache days (p<0.001), cumulative headache hours on headache days (p<0.001), headache episodes (p=0.028), and migraine episodes (p=0.018) and the percentage of patients with severe Headache Impact Test-6 category (p<0.001). At Week 24, change from baseline in frequency of acute headache medication intakes (secondary endpoint) was not statistically significant (p=0.210) between groups, except for triptan intakes (p<0.001), where the onabotulinumtoxinA-treated group was favored. OnabotulinumtoxinA was effective and well tolerated as headache prophylaxis in CM+MO patients.

A double-blind, randomized, placebo-controlled comparison of botulinum toxin type a injection sites and doses in the prevention of episodic migraine.

BACKGROUND: Several randomized, controlled studies have reported benefits of botulinum toxin type A (BoNTA; Allergan Inc., Irvine, CA, USA) over placebo in the treatment of migraine. Some studies reported significant benefits at dosages as low as 16 U, while other studies reported safety, tolerability, and efficacy at dosages up to 260 U. However, the optimal treatment paradigm and patient population have yet to be defined. OBJECTIVE: To compare different injection sites and doses of BoNTA in the prevention of episodic migraine. DESIGN AND METHODS: This was a randomized, double-blind, placebo-controlled study of 232 patients with a history of four to eight moderate to severe migraines per month, with or without aura. Patients were randomized to placebo or one of four BoNTA groups that received injections into different muscle regions: frontal (10 U), temporal (6 U), glabellar (9 U), or all three areas (total dose 25 U). For 3 months following a single treatment, patients recorded migraine-related variables in a daily diary. RESULTS: BoNTA and placebo produced comparable decreases from baseline in the frequency of migraines (P > or = 0.411). In general, no statistically significant differences were observed for any efficacy variable. The overall rates of adverse events (any type) or treatment-related adverse events were similar among the groups. CONCLUSIONS: In this exploratory study of episodic migraine patients, low-dose injections of BoNTA into the frontal, temporal, and/or glabellar muscle regions were not more effective than placebo. BoNTA was safe and well tolerated. Future studies may examine higher BoNTA doses, flexible injection sites, multiple treatments, and disallow concomitant prophylactic medications.

Botulinum toxin type a for the prophylaxis of chronic daily headache: subgroup analysis of patients not receiving other prophylactic medications: a randomized double-blind, placebo-controlled study.

OBJECTIVE: To assess the efficacy and safety of botulinum toxin type A (BoNT-A; BOTOX, Allergan, Inc., Irvine, CA) for the prophylaxis of headaches in patients with chronic daily headache (CDH) without the confounding factor of concurrent prophylactic medications. BACKGROUND: Several open-label studies and an 11-month, randomized, double-blind, placebo-controlled study suggest that BoNT-A may be an effective therapy for the prophylaxis of headaches in patients with CDH. DESIGN AND METHODS: This was a subgroup analysis of an 11-month, randomized double-blind, placebo-controlled study of BoNT-A for the treatment of adult patients with 16 or more headache days per 30-day periods conducted at 13 North American study centers. All patients had a history of migraine or probable migraine. This analysis involved data for patients who were not receiving concomitant prophylactic headache medication and who constituted 64% of the full study population. Following a 30-day screening period and a 30-day single-blind, placebo injection, eligible patients were injected with BoNT-A or placebo and assessed every 30 days for 9 months The following efficacy measures were analyzed per 30-day periods: change from baseline in number of headache-free days; change from baseline in headache frequency; proportion of patients with at least 30% or at least 50% decrease from baseline in headache frequency; and change from baseline in mean headache severity. Acute medication use was assessed, and adverse events were recorded at each study visit. RESULTS: Of the 355 patients randomized in the study, 228 (64%) were not taking prophylactic medication and were included in this analysis (117 received BoNT-A, 111 received placebo injections). Mean age was 42.4+/-10.90 years; the mean frequency of headaches per 30 days at baseline was 14.1 for the BoNT-A group and 12.9 for the placebo group (P=.205). After two injection sessions, the maximum change in the mean frequency of headaches per 30 days was -7.8 in the BoNT-A group compared with only -4.5 in the placebo group (P=.032), a statistically significant between-group difference of 3.3 headaches. The between-group difference favoring BoNT-A treatment continued to improve to 4.2 headaches after a third injection session (P=.023). In addition, BoNT-A treatment at least halved the frequency of baseline headaches in over 50% of patients after three injection sessions compared to baseline. Statistically significant differences between BoNT-A and placebo were evident for the change from baseline in headache frequency and headache severity for most time points from day 180 through day 270. Only 5 patients (4 patients receiving BoNT-A treatment; 1 patient receiving placebo) discontinued the study due to adverse events and most treatment-related events were transient and mild to moderate in severity. CONCLUSIONS: BoNT-A is an effective and well-tolerated prophylactic treatment in migraine patients with CDH who are not using other prophylactic medications.