Efficacy definitions for migraine studies

Guidelines of the International Headache Society for controlled trials of preventive treatment of migraine in children and adolescents, 1st edition

Background

Because the results of clinical trials of investigational treatments influence regulatory policy, prescribing patterns, and use in clinical practice, high quality trials are an essential component of the evidence base for migraine. The International Headache Society has published guidelines for clinical trials in adults with migraine since 1991. With multiple issues specific to children and adolescents with migraine, as well as the emergence of novel trial designs and advances in pharmaceuticals, biologics, devices, and behavioural interventions, there is a need for guidance focusing on issues specific to the conduct of clinical trials in children and adolescents with migraine.

Objectives

The objective of these guidelines is to provide a contemporary, standardized, and evidence-based approach to the design, conduct, and reporting of well-controlled clinical trials of preventive treatment of migraine in children and adolescents.

Methods

The development of these guidelines was based on guidelines previously published by the International Headache Society and regulatory bodies. The recommendations are evidence-based, where available. The process included consultations among various committees, roundtable discussions among stakeholders (lay people and the pharmaceutical industry), and open consultation with the IHS membership on the final draft.

Results

A series of recommendations addressing the major issues in clinical trials in children and adolescents with migraine is provided. Recommendations are supported by evidence-based practice and validated methodologies, where available. Supporting comments are provided to clarify ambiguities.

Conclusions

These guidelines should be consulted and used in designing and conducting clinical trials of preventive treatments in children and adolescents with migraine.

Guidelines of the International Headache Society for controlled trials of acute treatment of migraine attacks in adults: Fourth edition

The quality of clinical trials is an essential part of the evidence base for the treatment of headache disorders. In 1991, the International Headache Society Clinical Trials Standing Committee developed and published the first edition of the Guidelines for controlled trials of drugs in migraine. Scientific and clinical developments in headache medicine led to second and third editions in 2000 and 2012, respectively. The current, fourth edition of the Guidelines retains the structure and much content from previous editions. However, it also incorporates evidence from clinical trials published after the third edition as well as feedback from meetings with regulators, pharmaceutical and device manufacturers, and patient associations. Its final form reflects the collective expertise and judgement of the Committee. These updated recommendations and commentary are intended to meet the Society's continuing objective of providing a contemporary, standardized, and evidence-based approach to the conduct and reporting of randomised controlled trials for the acute treatment of migraine attacks.

What efficacy measures are clinically relevant and should be used in Cochrane Reviews of acute migraine trials? A viewpoint

BACKGROUND

Cochrane Reviews are methodologically of high quality but the clinical relevance of analysed efficacy measures (EMs) should also be assessed.

METHODS

The clinical relevance of EMs used in one systematic Cochrane review of oral zolmitriptan for migraine headache was evaluated.

RESULTS

The following EMs were used: pain free at two hours (30%), headache relief at two hours (60%), sustained pain free for 24 hours (19%) and sustained headache relief for 24 hours (39%). These EMs were also used in four other Cochrane reviews of acute migraine treatment. Of these EMs sustained headache relief for 24 h is not judged clinically relevant.

CONCLUSION

Pain free and sustained pain free are clinically relevant, but the responses are rather low, demonstrating that there is a need for improvement of acute drug treatment in migraine.

Ten years of rizatriptan: from development to clinical science and future directions

The year 2008 marked the 10th anniversary since rizatriptan was first launched for the acute treatment of migraine. In this article we discuss the concepts that motivated the preclinical and clinical development of rizatriptan, the clinical evidence that has driven its use over the past decade, rizatriptan's overall contribution to the field, and future directions for research.

WITHDRAWN: Rizatriptan for acute migraine

BACKGROUND

There are a number of different drug treatments for acute migraine, including currently four triptans, with several more likely to become available in the future. There is a need for evidence-based information to help determine the balance of benefit and harm for acute migraine treatment.

OBJECTIVES

To quantitatively assess the efficacy of a single dose of rizatriptan (Maxalt) for treating a single migraine attack using the outcomes of headache response and pain-free response at half-an-hour, one hour, two hours, and sustained relief over 24 hours. To express efficacy in terms of numbers-needed-to-treat (NNTs).

SEARCH STRATEGY

Trials were identified by searching MEDLINE (1966-July 2000), EMBASE (1980-June 2000), the Cochrane Library (Issue 3, 2000) and the Oxford Pain Relief Database (1950-1994). Date of last search: July 2000.

SELECTION CRITERIA

The inclusion criteria were randomised, placebo-controlled trials of rizatriptan for acute migraine; double-blind design; International Headache Society diagnostic criteria for migraine with or without aura; single migraine attack; single-dose treatment at standard doses; adult population; baseline pain of moderate or severe intensity using a four-point standardised rating scale; dichotomous or percentage data for at least one of the main efficacy outcomes; and full journal publication.

DATA COLLECTION AND ANALYSIS

Main outcomes considered were i) headache response at two hours, ii) headache response at one hour, iii) pain-free response at two hours, iv) sustained relief over 24 hours, v) pain-free response at 24 hours and vi) adverse effects. Minor outcomes were headache response and pain-free response at half-an-hour and four hours, and pain-free response at one hour. Dichotomous or percentage data were extracted and used to calculate the relative benefit (RB) and number-needed-to-treat (NNT) for each outcome.

MAIN RESULTS

Seven trials met our inclusion criteria, with 2626 patients given rizatriptan and 902 given placebo. Significant benefit of rizatriptan over placebo was shown for both doses of rizatriptan (5 mg and 10 mg) for all five main efficacy outcomes (ranging from one to 24 hours). A dose response was seen for the main outcomes. It was not possible to analyse adverse effects information in a meaningful way.

AUTHORS' CONCLUSIONS

Rizatriptan 5 mg and 10 mg are effective in treating acute migraine, with a dose-related increase in efficacy.

Pain Characteristics of the Acute Migraine Attack

OBJECTIVES

This study describes the pain characteristics of the acute migraine attack, including time of onset, time to peak, duration, intensity, quality, aggravation by activity, as well as recurrence frequency and time to recurrence, in a tertiary care practice.

BACKGROUND

The literature documenting the characteristics of the pain of the acute attack of migraine is sparse.

METHODS

A total of 1,283 migraine patients (ICHD 1.1, 1.2, 1.5.1, and ICHD 1.6 [total migraine population]) were evaluated at first visit. Headache character (throbbing, aching, pressure, stabbing scaled grade 0 to 3; 0 = none; 1 = mild; 2 = moderate; 3 = severe), intensity (for average, minimum, and maximum intensity headaches, scaled 0 to 10), lifetime duration, frequency per month, duration in minutes (for average, minimum, maximum duration headaches), time of onset of headache (morning, afternoon, evening, night, anytime), aggravation of headache with activity (scaled 0 to 3), percentage recurrence, time to recurrence, were recorded. Patients were stratified into different groups; ICHD 1.1, 1.2, and 1.5.1 (migraine) ICHD 1.1 and 1.2 (episodic migraine), ICHD 1.5.1 (chronic migraine), and ICHD 1.6 (probable migraine). Patients with unremitting daily headache were excluded.

RESULTS

DEMOGRAPHICS

A total of 84.3% patients were female, and the mean age was 37.7, ranging from 13.0 to 80.5 years. Eight hundred seventy-four patients were classified as ICHD 1.1, 1.2, and 1.5.1 (migraine), 524 with ICHD 1.1 and 1.2 (episodic migraine), 350 with ICHD 1.5.1 (chronic migraine), and 409 with ICHD 1.6 (probable migraine).

STUDY RESULTS

Time of onset of headache was mostly in the morning in 18.7%, afternoon 13.5%, evening 4.0%, during night 9.4%, and "anytime" 54.3%, with minor differences seen in different headache types, gender, presence of aura, and headache frequency. The median time to peak of the headache was greater in migraine than probable migraine (90 minutes vs. 60 minutes; P < .01). Headache duration medians were reported as minimum of 12 hours, maximum of 48 hours with an average of 24 hours, females being greater than males in average headache (24.0 vs. 12.0; P < .01), minimum (24.0 vs. 8; P < .05), and maximum (48.0 vs. 24.0; P < .01). Only the minimum duration differed between migraine and atypical migraine (12.0 vs. 4.0; P < .01). Headache intensity medians were as follows: average intensity 7/10, minimum 4/10, and maximum 10/10, with no differences in migraine versus probable migraine, gender, or headache frequency. Headache intensity median was consistently greater in migraine episodic than chronic migraine (average 8.0 vs. 6.5, minimum 4.5 vs. 3.0, maximum 10.0 vs. 9.0, all P < .05). Headache character (greater than grade 1) was throbbing (73.5%), aching (73.8%), pressure (75.4%), and stabbing (42.6%) with significantly more throbbing in migraine than in probable migraine (73.5% vs. 63.2%; P < .01) and more aching in chronic than in episodic migraine (65.4% vs. 63.1%; P < .05). Headache increased by activity was present in 90.2% of patients, grade 1 in 13.8%, grade 2 in 30.8%, and grade 3 in 45.5% of patients. The presence of activity aggravating headache was more likely to be associated with headache triggers, maximum headache severity, longer time to 50% reduction of headache, and longer time to absent headache with triptans, and more headache-associated symptoms, and longer postdrome duration (all P < .05). Recurrence rate was 43.8% with the median time to recurrence being 8 hours. Significantly less recurrence occurred with episodic than chronic migraine (30.0% vs. 50.0%; P < .01).

CONCLUSIONS

This study provides an in-depth description of pain features in the acute migraine attack. It was found that a significant number of patients need to be provided with the means of treating headache rapidly in at least some of their headaches and that headache recurrence needs to be addressed in a large number of patients.

Emerging drugs in migraine treatment

Ergot alkaloids have been the mainstay of acute migraine therapy for most of the 20th century. They have been supplanted by sumatriptan-like drugs ('triptans'), which, while keeping some of the ergotś mechanisms of action, show improved safety profiles due to their increased receptor selectivity. However, triptans are still far from being perfect drugs: they can constrict human coronary arteries at therapeutic doses and, therefore, are contra-indicated in the presence of cardiovascular disease. Another problem with these agents is recurrence of moderate-to-severe pain within 24 h of initial headache relief. While mechanism-driven drug design has led to the development of various novel, albeit still imperfect, acute antimigraine medications, only a few new prophylactic agents have been made available to migraine clinicians. The efficacy of most, if not all of them has been discovered serendipitously. This is probably due to the fact that, while the pathophysiology of a migraine attack is now reasonably understood, the mechanisms leading to an attack are still mostly unknown. This update analyses the profile of some antimigraine drugs in clinical trials, their mode of action and their potential advantages or drawbacks over already available agents.

A cost-effectiveness analysis of eletriptan 40 and 80 mg versus sumatriptan 50 and 100 mg in the acute treatment of migraine

OBJECTIVES

This article explores the application of cost-effectiveness analysis in a comparison of eletriptan and sumatriptan in the acute treatment of migraine.

METHODS

The study employs data from a randomized, double-blind, placebo-controlled clinical trial comparison of oral eletriptan (40 and 80 mg) and oral sumatriptan (50 and 100 mg). Analyses were undertaken using two composite measures of treatment outcome constructed to reflect the requirements of patients more comprehensively than the conventional efficacy indicator of headache response at 2 hours. On the cost side of the equation, reflecting the health-care system perspective of the analysis, drug costs for initial dosing, second dosing for nonresponse, and recurrence and rescue medication were taken into account.

RESULTS

The analysis found that eletriptan treatment resulted in lower costs per successfully treated attack than those of sumatriptan under both outcome criteria.

CONCLUSION

Further refinement of outcomes measurement in migraine would be valuable and eletriptan has a potentially important role to play in the cost-effective management of the disorder.

Headache Recurrence and Treatment

The definition of recurrence includes the following: any headache occurring after a headache-free state at 2 hours and within 24 hours after intake of drug; a headache that has never been studied systematically; a headache that may not be an outcome of drug treatment; a headache that may be due to the inherent nature of migraine and individual patient characteristics such as duration of attack; and headache for which effective treatment may be a re-dose of the initial medication or addition of steroidal or nonsteroidal anti-inflammatory medications.

Pharmacological treatments for acute migraine: quantitative systematic review

We wanted to compare the analgesic efficacy and adverse effects of pharmacological treatments for acute migraine through a systematic review of randomised controlled trials in patients with acute migraine pain of moderate to severe intensity. Trials were identified from systematic searching of bibliographic databases. For eletriptan information from all trials was supplied by Pfizer Inc. Outcomes sought were headache relief at 1 and 2h, patients pain free at 2h and sustained relief over 24h for treatments compared with placebo. Numbers-needed-to-treat (NNTs) were calculated, together with relative benefit. Information on adverse effects was also collected. Comparisons of relative efficacy used the same definition of headache, the same degree of pain at the start of treatment and the same definitions of outcomes, and always compared with placebo. Forty-eight publications reporting on 54 trials were included in the meta-analyses, with 79 placebo comparisons for the primary outcome of headache relief at 2h. Information on any outcome was available for nine oral medications, two intranasal medications and subcutaneous sumatriptan in 21,022 patients. For headache relief at 2h NNTs ranged from 2.0 for subcutaneous sumatriptan 6mg to 5.4 for naratriptan 2.5mg. For patients pain free at 2h NNTs ranged from 2.1 for subcutaneous sumatriptan 6mg to 8.6 for aspirin 900mg plus metoclopramide 10mg. For sustained relief over 24h NNTs ranged from 2.8 for eletriptan 80mg to 8.3 for rizatriptan 5mg. It was not possible to systematically review adverse effects data. Most interventions are effective. There is considerable information on relative efficacy for a number of outcomes.

Assessing the efficacy of drugs for the acute treatment of migraine: issues in clinical trial design

Clinical trials of therapies for acute migraine attacks have evolved over the years from open-label, small observational studies to highly structured randomised, controlled trials. The International Headache Society Committee on Clinical Trials in Migraine developed a tool to guide in designing scientifically sound trials. The proof of effect is best achieved in a clinical trial with: clearly defined objectives;a well-characterised study population, identified using well-validated diagnostic tools;proper randomisation and blinding;inclusion of a placebo arm, with proper balancing of patients receiving placebo and those receiving active drug;adequate study power; and appropriate statistical methods. Both parallel and crossover studies may be suitable in clinical trials of antimigraine agents, although the latter are a better choice in patient preference and bioequivalence studies. Although various efficacy measures are used to assess treatment effect, the 2-hour pain free rate (total resolution of pain within 2 hours after an initial moderate to severe headache) is preferred because it is clinically relevant and is relatively 'placebo-insensitive'. Various migraine surveys have indicated that a rapid onset of therapeutic effect is a highly desirable attribute of an antimigraine drug. Therefore, accurate measurements of treatment effect before 2 hours are becoming increasingly emphasised. Consistency of effect across multiple attacks adds to the understanding of the therapeutic efficacy of a test drug. Finally, preference and satisfaction studies allow us to assess patients' global impression of a particular treatment, weighing the positive effects on pain and associated symptoms of migraine against potential adverse effects.

Selective seratonin 1F (5-HT(1F)) receptor agonist LY334370 for acute migraine: a randomised controlled trial

BACKGROUND

Triptans (5-HT(1B/1D) receptor agonists) are effective drugs for acute migraine, but the side-effect of coronary vasoconstriction restricts their use in patients who are at risk of coronary artery disease. We have studied the efficacy of LY334370, a selective serotonin 1F (5-HT(1F)) receptor agonist with preclinical efficacy and no vasoconstriction, for migraine relief.

METHODS

We gave LY334370 (20, 60, or 200 mg) or placebo to 99 outpatients with moderate or severe migraine headaches in a double blind, parallel group study. We measured efficacy by sustained response, response at 2 h, pain free at 2 h, and sustained pain free.

FINDINGS

The proportions of patients with defined endpoints for placebo and LY334370 20, 60, and 200 mg, respectively, were: sustained response, two of 26 (8%), three of 22 (14%), 11 of 30 (37%), and 11 of 21 (52%) (dose response p<0.001); response, five of 26 (19%), four of 22 (18%), 15 of 30 (50%), and 15 of 21 (71%) (p<0.001); pain free, one of 26 (4%), none of 22, eight of 30 (27%), and eight of 21 (38%) (p=0.001); sustained pain free, one of 26 (4%), none of 22, seven of 30 (23%), and seven of 21 (33%) (p=0.002); recurrence rates, one of five (20%), none of four, four of 15 (27%), and three of 15 (20%). More patients given LY334370 than placebo reported asthenia, somnolence, and dizziness.

INTERPRETATION

Our findings show that LY334370 is effective in treatment of acute migraine through selective trigeminovascular neuronal inhibition.

Meta-analysis of rizatriptan efficacy in randomized controlled clinical trials

Data from seven randomized, placebo-controlled, double-blind phase III clinical trials were analysed to further evaluate the efficacy of rizatriptan 10 mg (n = 2068) in comparison with placebo (n = 1260) and rizatriptan 5 mg (n = 1486) for the acute treatment of a migraine attack. Migraine was diagnosed according to International Headache Society criteria. Headache severity, associated migraine symptoms and functional disability were measured immediately before dosing and at 0.5, 1, 1.5 and 2 h. Headache recurrence (return of moderate or severe headache after an initial response) was also recorded. In addition to conventional pain relief (reduction of moderate or severe headache to mild or none) and pain free measures, the analysis looked at the elimination of associated migraine symptoms and disability in patients who had symptoms or disability at baseline. Maintenance of pain relief or pain-free status over 24 h was also analysed. At 2 h, rizatriptan 10 mg was significantly more effective than placebo for pain relief (71% vs. 38%, P < 0.001), and for elimination of pain, nausea, photophobia, phonophobia and functional disability. The benefit was maintained over 24 h; 37% of patients on rizatriptan 10 mg had sustained pain relief vs. 18% for placebo (P < 0.001). Rizatriptan 10 mg was also more effective than rizatriptan 5 mg, with a significant superiority at 2 h on all measures except for elimination of nausea. The benefit was maintained over 24 h; 38% of patients on rizatriptan 10 mg had sustained pain relief vs. 32% for rizatriptan 5 mg (P = 0.001).

Rizatriptan for acute migraine

BACKGROUND

There are a number of different drug treatments for acute migraine, including currently four triptans, with several more likely to become available in the future. There is a need for evidence-based information to help determine the balance of benefit and harm for acute migraine treatment.

OBJECTIVES

To quantitatively assess the efficacy of a single dose of rizatriptan (Maxalt) for treating a single migraine attack using the outcomes of headache response and pain-free response at half-an-hour, one hour, two hours, and sustained relief over 24 hours. To express efficacy in terms of numbers-needed-to-treat (NNTs).

SEARCH STRATEGY

Trials were identified by searching MEDLINE (1966-July 2000), EMBASE (1980-June 2000), the Cochrane Library (Issue 3, 2000) and the Oxford Pain Relief Database (1950-1994). Date of last search: July 2000.

SELECTION CRITERIA

The inclusion criteria were randomised, placebo-controlled trials of rizatriptan for acute migraine; double-blind design; International Headache Society diagnostic criteria for migraine with or without aura; single migraine attack; single-dose treatment at standard doses; adult population; baseline pain of moderate or severe intensity using a four-point standardised rating scale; dichotomous or percentage data for at least one of the main efficacy outcomes; and full journal publication.

DATA COLLECTION AND ANALYSIS

Main outcomes considered were i) headache response at two hours, ii) headache response at one hour, iii) pain-free response at two hours, iv) sustained relief over 24 hours, v) pain-free response at 24 hours and vi) adverse effects. Minor outcomes were headache response and pain-free response at half-an-hour and four hours, and pain-free response at one hour. Dichotomous or percentage data were extracted and used to calculate the relative benefit (RB) and number-needed-to-treat (NNT) for each outcome.

MAIN RESULTS

Seven trials met our inclusion criteria, with 2626 patients given rizatriptan and 902 given placebo. Significant benefit of rizatriptan over placebo was shown for both doses of rizatriptan (5 mg and 10 mg) for all five main efficacy outcomes (ranging from one to 24 hours). A dose response was seen for the main outcomes. It was not possible to analyse adverse effects information in a meaningful way.

REVIEWER'S CONCLUSIONS

Rizatriptan 5 mg and 10 mg are effective in treating acute migraine, with a dose-related increase in efficacy.