Use of the sustained pain-free plus no adverse events endpoint in clinical trials of triptans in acute migraine

Recent Advances in Pharmacotherapy for Episodic Migraine

In 2018, three calcitonin gene-related peptide (CGRP) pathway monoclonal antibodies, erenumab, fremanezumab and galcanezumab, were approved in various parts of the world, including Europe and the US, and another, eptinezumab, is pending, for the prevention of migraine. In this article, episodic migraine treatment is reviewed, although these medicines are approved and are just as effective for chronic migraine. These new medicines usher a new phase in the preventive management of migraine with migraine-specific treatments. Data from phase III trials of CGRP pathway monoclonal antibodies have shown they are efficacious, with adverse effect rates comparable to placebo. The combination of clear efficacy and excellent tolerability will be welcome in an area where poor adherence to current preventives is common. Rimegepant, ubrogepant and lasmiditan are migraine-specific acute therapies yet to be approved by regulators. Phase III data for the respective CGRP receptor antagonists, the gepants, and the serotonin 5-HT_1F receptor agonist, the ditan, have been positive and free of cardiovascular adverse effects. These medicines are not vasoconstrictors. When approved, they could meet the acute therapy demand of patients with cardiovascular risk factors where triptans are contraindicated. Beyond this, gepants will see the most disruptive development in migraine management in generations with medicines that can have both acute and preventive effects, the latter evidenced by data from the discontinued drug telcagepant and the early-phase drug atogepant. Moreover, one can expect no risk of medication overuse syndromes with gepants since the more patients take, the less migraines they have. During the next years, as experience with monoclonal antibodies grows in clinical practice, we can expect an evolution in migraine management to take shape. Clinicians will be able to offer treatment patients want rather than trying to fit migraineurs into therapeutic boxes for their management. Despite pessimistic susurrations of a largely addlepated form, many patients, and physicians, will welcome new options, and the challenges of new treatment paradigms, with optimism.

Almotriptan: a review of 20 years' clinical experience

Introduction: Almotriptan (ALT), a serotonin 5-HT_1B/1D agonist has been used in the acute treatment of migraine with or without aura for 20 years, accumulating data on more than 15,000 patients in studies and from an estimated >150 million treated migraine attacks in daily clinical practice. The last major review of ALT was written almost 10 years ago. The current narrative review provides an overview of the experience gained with almotriptan over that time, and highlights data published in the last decade. Areas covered: Randomized clinical trials, observational studies, postmarketing studies and meta-analyses involving ALT for the treatment of acute migraine identified through a systematic literature search. Expert opinion: Triptans are a mainstay of anti-migraine treatment. Findings with ALT over the last 10 years have reinforced the positive efficacy and tolerability results that were reported during the first 10 years following its introduction. In particular, more recent clinical results have confirmed its efficacy in women with menstrual migraine, the usefulness of early intervention, long-term benefit in adults, and also its efficacy and safety in adolescents. Overall, ALT can be considered an optimal choice for managing acute migraine resistant to first-line drugs.

CGRP – a target for acute therapy in migraine: Clinical data

Background

A better understanding of the mechanisms underlying the migraine attack has reinforced the concept that migraine is a complex brain disease, and has paved the way for the development of new migraine specific acute treatments. In recent years, targeting the calcitonin gene-related peptide and its receptors has been one of the most promising pharmacological strategies for both acute and preventive treatment of migraine.

Findings

Randomized double-blind placebo-controlled trials have demonstrated the superiority of small molecule calcitonin gene-related peptide receptor antagonists (gepants) over placebo in treating acute migraine attacks measured as the two-hour pain free endpoint. Gepants also improved migraine associated symptoms, such as nausea, photophobia and phonophobia. Two of the class have had their development stopped because of hepatotoxicity, which is emerging as being due to metabolites. Gepants have a good tolerability and can be safely used in patients with stable cardiovascular disease.

Conclusion

Exciting results have been obtained targeting the calcitonin gene-related peptide pathway to abort acute migraine attacks, thus reinforcing the relevance of mechanism-based treatments specific for migraine.

Pharmacological Acute Migraine Treatment Strategies: Choosing the Right Drug for a Specific Patient

Background:

In our targeted review (Section 2), 12 acute medications received a strong recommendation for use in acute migraine therapy while four received a weak recommendation for use. Strong recommendations were made to avoid use of two other medications, except for exceptional circumstances. Two anti-emetics received strong recommendations for use as needed.

Objective:

To organize the available acute migraine medications into acute migraine treatment strategies in order to assist the practitioner in choosing a specific medication(s) for an individual patient.

Methods:

Acute migraine treatment strategies were developed based on the targeted literature review used for the development of this guideline (Section 2), and a general literature review. Expert consensus groups were used to refine and validate these strategies.

Results:

Based on evidence for drug efficacy, drug side effects, migraine severity, and coexistent medical disorders, our analysis resulted in the formulation of eight general acute migraine treatment strategies. These could be grouped into four categories: 1) two mild-moderate attack strategies, 2) two moderate-severe attack or NSAID failure strategies, 3) three refractory migraine strategies, and 4) a vasoconstrictor unresponsive-contraindicated strategy. In addition, strategies were developed for menstrual migraine, migraine during pregnancy, and migraine during lactation. The eight general treatment strategies were coordinated with a “combined acute medication approach” to therapy which used features of both the “stratified” and the “step care across attacks” approaches to acute migraine management.

Conclusions:

The available medications for acute migraine treatment can be organized into a series of strategies based on patient clinical features. These strategies may help practitioners make appropriate acute medication choices for patients with migraine.

Efficacy endpoints in migraine clinical trials: the importance of assessing freedom from pain

Many efficacy endpoints have been used in clinical trials of acute migraine pharmacotherapy. Headache response or headache relief (i.e., moderate/severe pain reduced to mild/no pain) at a single, specified time-point, traditionally the primary endpoint, and headache recurrence (i.e., return of pain after initial postdose relief) are inadequate. Headache relief does not provide information about pain-free response and counts a partial response as a treatment success. Headache recurrence can reflect sustained efficacy but is confounded by initial response to treatment, because ineffective drugs have low recurrence rates. The International Headache Society (IHS) guidelines state that 2 hour pain-free response and sustained pain-free response (i.e., freedom from pain with no recurrence or use of rescue or study medication 2-24 hours postdose) provide the most clinically relevant information about the efficacy of migraine pharmacotherapy. The pain-free criterion counts partial responses as failures and thus is a more rigorous test of therapeutic benefit than headache relief, and the two endpoints together incorporate the main treatment attributes that determine patient satisfaction. As an example, consider needle-free subcutaneous sumatriptan and oral triptan tablets. An open-label study of needle-free subcutaneous sumatriptan by Cady and colleagues found that 2 hour pain-free response and sustained pain-free response were 64% and 42% respectively. For oral triptan tablets, the 2001 metaanalysis by Ferrari and colleagues reported 2 hour pain-free response rates ranging from 23% to 38% and sustained pain-free response rates ranging from 11% to 26%. The measures of pain-free response 2 hours postdose and sustained pain-free response can differentiate among treatments and be used to guide therapeutic choices.

Acute migraine therapy: new drugs and new approaches

OPINION STATEMENT

The conceptual shift of our understanding of migraine from a vascular disorder to a brain disorder has dramatically altered the approach to the development of new medicines in the field. Current pharmacologic treatments of acute migraine consist of nonspecific and relatively specific agents. Migraine-specific drugs comprise two classes, the ergot alkaloid derivatives and the triptans, serotonin 5-HT(1B/1D) receptor agonists. The ergots, consisting of ergotamine and dihydroergotamine (DHE), are the oldest specific antimigraine drugs available and are considered relatively safe and effective. Ergotamine has been used less extensively because of its adverse effects; DHE is better tolerated. The triptan era, beginning in the 1990s, was a period of considerable change, although these medicines retained vasoconstrictor actions. New methods of delivering older drugs include orally inhaled DHE and the transdermal formulation of sumatriptan, both currently under study. Novel medicines being developed are targeted at neural sites of action. Serotonin 5-HT(1F) receptor agonists have proven effective in phase II studies and have no vascular actions. Calcitonin gene-related peptide (CGRP) receptor antagonists are another promising nonvasoconstrictor approach to treating acute migraine. Olcegepant (BIBN4096BS) and telcagepant (MK-0974) have been shown to be safe and effective in phase I, II, and (for telcagepant) phase III clinical trials. Other targets under investigation include glutamate (AMPA/kainate), TRPV1, prostanoid EP4, and nitric oxide synthase. With new neural targets and the potential for therapeutic advances, the next era of antimigraine medications is near.

Almotriptan: a review of 10 years' clinical experience

Almotriptan, a serotonin 5-HT 1B/1D agonist, was developed for the acute treatment of migraine with or without aura and has been available for 10 years. This article evaluates the wealth of experience that has been obtained with almotriptan, including large randomized clinical trials (RCTs) and post-marketing studies that more closely reflect everyday clinical practice. Initial RCTs required patients to take almotriptan when migraine pain was of moderate or severe intensity, and found that 12.5 mg provided optimal outcomes for both pain relief and tolerability. Almotriptan effectively improved 2-h pain-relief, reduced migraine-associated symptoms and demonstrated low recurrence rates. These findings were also shown in patient subgroups, such as adolescents and menstrual migraineurs. A secondary finding in these trials was that patients who took almotriptan early, when the pain was still mild, achieved better outcomes. This prompted the initiation of studies designed to assess the effect of almotriptan in early intervention. Open-label trials reported improvements in pain-free end points (2 h, 24 h), and subsequent RCTs confirmed these findings. Pharmacovigilance data from more than 100 million tablets dispensed worldwide have confirmed that almotriptan is associated with a low occurrence of adverse effects, which, in clinical trials, has been shown to be similar to that observed with placebo. The clinical evidence obtained and comparisons made over a decade of use have demonstrated that almotriptan is one of the more effective and fast-acting triptans available, with a placebo-like tolerability profile. This suggests that almotriptan is an excellent choice for patients requiring specific acute migraine treatment.

Randomized controlled trial of the CGRP receptor antagonist MK-3207 in the acute treatment of migraine

Background: This study evaluated the CGRP receptor antagonist MK-3207 for acute treatment of migraine.

Methods: Multicenter, double-blind, randomized, placebo-controlled, parallel-group, two-stage adaptive study with two interim efficacy analyses to facilitate optimal dose selection. Migraine patients were initially randomized to MK-3207 2.5, 5, 10, 20, 50 and 100 mg or placebo to treat a moderate/severe migraine. One or more doses were to be discontinued based on the first interim analysis and a lower or higher dose could be added based on the second interim analysis. The primary endpoint was two-hour pain freedom.

Results: A total of 547 patients took study medication. After the first interim analysis, the two lowest MK-3207 doses (2.5, 5 mg) were identified as showing insufficient efficacy. Per the pre-specified adaptive design decision rule, only the 2.5-mg group was discontinued and the five highest doses (5, 10, 20, 50, 100 mg) were continued into the second stage. After the second interim efficacy analysis, a 200 mg dose was added due to insufficient efficacy at the top three (20, 50, 100 mg) doses. A positive dose-response trend was demonstrated when data were combined across all MK-3207 doses for two-hour pain freedom ( p < .001). The pairwise difference versus placebo for two-hour pain freedom was significant for 200 mg ( p < .001) and nominally significant for 100 mg and 10 mg ( p < .05). The incidence of adverse events appeared comparable between active treatment groups and placebo, and did not appear to increase with increasing dose.

Conclusions: MK-3207 was effective and generally well tolerated in the acute treatment of migraine.

Sustained pain freedom and no adverse events as an endpoint in clinical trials of acute migraine treatments: Application to patient-level data from a trial of the CGRP receptor antagonist, telcagepant, and zolmitriptan

Background: Endpoints used to evaluate the efficacy of acute anti-migraine drugs do not measure the tolerability. Sustained pain-free response with no adverse events has been recommended as a composite endpoint which measures the efficacy and tolerability attributes that patients desire.

Methods: The aim of this study was to evaluate new composite efficacy-plus-tolerability endpoints based on a post-hoc analysis of patient-level data from a previous randomized, placebo-controlled trial of the calcitonin gene-related peptide (CGRP) receptor antagonist, telcagepant, and zolmitriptan in the acute treatment of migraine. Endpoints were 2–24-hour sustained pain freedom and no adverse events from 0–24 hours (SPF24NAE), 2–24 hour sustained pain relief and no adverse events from 0–24 hours (SPR24NAE), pain freedom at 2 hours and no adverse events from 0–24 hours (PF2NAE), and pain relief at 2 hours and no adverse events from 0–24 hours (PR2NAE).

Results: Compared with placebo, both telcagepant 300 mg and 150 mg achieved nominal superiority ( p values <.05) for SPF24NAE, SPR24NAE, PF2NAE and PR2NAE. Zolmitriptan 5 mg showed nominal superiority versus placebo for SPF24NAE, SPR24NAE and PF2NAE, but not PR2NAE. Telcagepant 300 mg showed nominal superiority versus zolmitriptan for SPF24NAE, SPR24NA and PR2NAE.

Conclusion: Composite efficacy-plus-tolerability endpoints may be useful for facilitating comparisons between treatments.

Triptans for the management of migraine

Migraine is a chronic, recurrent, disabling condition that affects millions of people in the US and worldwide. Proper acute care treatment for migraineurs is essential for a full return of function and productivity. Triptans are serotonin (5-HT)(1B/1D) receptor agonists that are generally effective, well tolerated and safe. Seven triptans are available worldwide, although not all are available in every country, with multiple routes of administration, giving doctors and patients a wide choice. Despite the similarities of the available triptans, pharmacological heterogeneity offers slightly different efficacy profiles. All triptans are superior to placebo in clinical trials, and some, such as rizatriptan 10 mg, eletriptan 40 mg, almotriptan 12.5 mg, and zolmitriptan 2.5 and 5 mg are very similar to each other and to the prototype triptan, sumatriptan 100 mg. These five are known as the fast-acting triptans. Increased dosing can offer increased efficacy but may confer a higher risk of adverse events, which are usually mild to moderate and transient in nature. This paper critically reviews efficacy, safety and tolerability for the different formulations of sumatriptan, zolmitriptan, rizatriptan, naratriptan, almotriptan, eletriptan and frovatriptan.

A trans-cultural comparison of the organisation of care at headache centres world-wide

Background: The need to provide better outcomes for patients with headache, and to minimise the costs involved in doing so, has prompted the search for new modes of service delivery by exploring the service organisation and nursing role from various cultural, economic and global perspectives.

Materials and Methods: This study was based on comparisons with the UK headache service up to 2007, the point at which this study was set up. This UK service was based at the National Hospital for Neurology and Neurosurgery (NHNN, UCLH Trust). Data were obtained from US headache centres in 2008 and from centres in Copenhagen, Bangkok, Sydney and Porto Alegre in 2009.

Results: A comparison shows the key components of services at all centres showing the team structure and size of service. Prominent features at the centres included: team-working, regular meetings, educational input, good access and communication among team members, headache-trained neurologists, specialist nursing at most centres, and the input of psychological and physical therapists at some centres.

Conclusions: The problems of tertiary headache care are very similar throughout the world and seem to transcend ethnic, cultural and economic considerations.

Cost effectiveness of pharmacotherapy for the prevention of migraine: a Markov model application

BACKGROUND

There are few data about the cost effectiveness of prophylactic medications for migraine. Clinical trials have shown several preventive agents to be useful in reducing the frequency of migraine attack while having tolerable side effects.

OBJECTIVE

To compare the cost effectiveness of adding preventive treatment to abortive therapy for acute migraine with abortive therapy for acute migraine alone in the primary care setting.

METHODS

A Markov decision analytic model with a cycle length of 1 day, a time horizon of 365 days and three health states was used to perform an analysis comparing the cost effectiveness and utility of five treatments for migraine prophylaxis (amitriptyline 75 mg/day, topiramate 100 and 200 mg/day, timolol 20 mg/day, divalproex sodium 1000 mg/day or propranolol 160 mg/day) with treatment of acute migraine alone for the management of migraine in the primary care setting. One-way and probabilistic sensitivity analyses were performed to test the robustness of the results.

RESULTS

The expected total annual cost for the use of preventive agents ranged from $US2932 to $US3887, compared with $US3960 for the use of abortive medications only. In the baseline analysis, use of each of the five preventive agents generated more quality-adjusted life-years (QALYs) and incurred lower costs compared with abortive medications only. Monte Carlo Simulation suggested that amitriptyline 75 mg/day was most likely to be considered a cost-effective option versus the other five therapies, followed by timolol 20 mg/day, topiramate 200 mg/day, topiramate 100 mg/day, divalproex sodium 1000 mg/day and propranolol 160 mg/day when the willingness-to-pay (WTP) for society is <$US18 000 per QALY gained.

CONCLUSIONS

Preventive medications appear to be a cost-effective approach to the management of migraine in the primary care setting compared with the approach of abortive treatment only. Among those preventive agents, probabilistic sensitivity analysis suggests that, when the societal WTP is <$US18 000 per QALY gained, amitriptyline 75 mg/day is most likely to be considered a cost-effective option.

Almotriptan for the treatment of acute migraine: a review of early intervention trials

Almotriptan is a serotonin (5-hydroxytryptamine)(1B/1D) receptor agonist (triptan) that has shown consistent efficacy in the acute treatment of migraine with excellent tolerability. It is an effective, well-tolerated and cost-effective triptan, as demonstrated by improvement in rigorous, patient-orientated end points, such as 'sustained pain-free without adverse events'. Results from post hoc analyses, observational studies and well-controlled, prospective clinical trials have shown that significant improvements can be achieved if almotriptan 12.5 mg is administered within an hour of migraine onset, particularly when pain is mild, rather than waiting until pain is moderate-to-severe. Benefits were also achieved with early treatment of moderate-to-severe pain. Time-to-treatment was the best predictor of headache duration, whereas initial headache intensity best predicted most other efficacy outcomes. Early administration of almotriptan 12.5 mg not only produced rapid symptomatic relief, it also improved the patient's quality of life and ability to resume normal daily functioning. Furthermore, the efficacy of almotriptan is not significantly affected by allodynia (purported to reduce the efficacy of triptans). Thus, the excellent efficacy and tolerability profile of almotriptan administered early in a migraine attack indicate that it may be a first-line treatment option in this common, underdiagnosed and undertreated disorder.

Safety and tolerability of frovatriptan in the acute treatment of migraine and prevention of menstrual migraine: Results of a new analysis of data from five previously published studies

BACKGROUND

Triptans are a recommended first-line treatment for moderate to severe migraine.

OBJECTIVE

Using clinical trial data, we evaluated the safety and tolerability of frovatriptan as acute treatment (AT) and as short-term preventive (STP) therapy for menstrual migraine (MM).

METHODS

Data from 2 Phase III AT trials (AT1: randomized, placebo controlled, 1 attack; AT2: 12-months, noncomparative, open label) and 3 Phase IIIb STP trials in MM (MMP1 and MMP2: randomized, placebo controlled, double blind, 3 perimenstrual periods; MMP3: open label, noncomparative, 12 perimenstrual periods) were analyzed. In AT1, patients treated each attack with frovatriptan 2.5 mg, sumatriptan 100 mg, or placebo. In AT2, they used frovatriptan 2.5 mg. In MMP1 and MMP2, women administered frovatriptan 2.5 mg for 6 days during the perimenstrual period, taking a loading dose of 2 or 4 tablets on day 1, followed by once-daily or BID frovatriptan 2.5 mg, respectively; in MMP3, they used BID frovatriptan 2.5 mg. In AT1, which was previously published in part, group differences in adverse events (AEs) were analyzed using the Fisher exact test, and response rates were compared using logistic regression. Post hoc analyses of sustained pain-free status with no AEs (SNAE) and sustained pain response with no AEs (SPRNAE) were performed using a 2-sample test for equality of proportions without continuity correction. For AT2 and the STP studies, data were summarized using descriptive statistics. Results of individual safety analyses for the STP studies were previously reported; the present report includes new results from a pooled analysis of MMP1 and MMP2 and a new analysis of MMP3 in which AEs were coded using Medical Dictionary for Regulatory Activities version 8.0.

RESULTS

AT1 included 1206 patients in the safety group; AT2 included 496. In the STP studies, safety data were collected for 1487 women. In AT1 and AT2, 85.6% and 88.3%, respectively, of enrolled patients were women. Overall, AEs were generally mild to moderate (AT studies: 82.3%-90.0%; STP studies: 78.9%89.5%). In AT1, 27.3% (131/480) of frovatriptan patients, 33.4% (161/482) of sumatriptan patients, and 14.8% (36/244) of placebo patients experienced an AE considered possibly or probably related to treatment (P < 0.001 for either drug vs placebo).There were no significant differences between frovatriptan and sumatriptan in SNAE at 4 to 24 hours or in SPRNAE at 2 to 24 hours or at 4 to 24 hours. In randomized, controlled STP trials for MM, AEs were reported by 57.8% (166/287, BID) and 63.4% (210/331, once daily) of frovatriptan users versus 62.8% (216/344) of placebo recipients. There were no consistent differences in AEs reported by patients with potential cardiovascular risk or in AEs related to the use of estrogencontaining contraceptives (ECCs).

CONCLUSIONS

In randomized controlled trials and 12-month open-label studies, frovatriptan was well tolerated in these women during AT and STP therapy for MM. Subgroup analyses provide preliminary evidence of tolerability in women using ECCs and in women with comorbidities that do not contraindicate triptan use but may be suggestive of cardiovascular risk.

Intranasal sumatriptan powder delivered by a novel breath-actuated bi-directional device for the acute treatment of migraine: A randomised, placebo-controlled study

Introduction: Intranasal sumatriptan is an option for the treatment of migraine; however, nasal delivery using conventional spray pumps is suboptimal.

Methods: Adult subjects ( n = 117) with migraine were enrolled in a multicentre, randomised, double-blind, parallel group, placebo-controlled study. A single migraine attack was treated in-clinic with sumatriptan 10 mg, sumatriptan 20 mg or placebo administered intranasally by a novel bi-directional powder delivery device when migraine was moderate or severe.

Results: A greater proportion of subjects who received sumatriptan were pain-free at 120 minutes compared with those who received placebo (10 mg/20 mg sumatriptan vs. placebo = 54%/57% vs. 25%, P < .05). Significant benefits were also observed for pain relief at 120 minutes (84%/80% vs. 44%, P < .001/.01) and as early as 60 minutes (73%/74% vs. 38%, P < .01) and for 48 hours sustained pain-free ( P < .05). Treatment-related adverse events were rare, with a metallic taste being the most commonly reported (10%/13%).

Conclusions: Sumatriptan nasal powder administered using the new device during a migraine attack was effective and well tolerated.

Fixed-dose Sumatriptan/Naproxen Sodium Compared with each Monotherapy Utilizing the Novel Composite Endpoint of Sustained Pain-free/no Adverse Events

A novel composite endpoint, sustained pain-free/no adverse events, was recently proposed as a more rigorous means of capturing in a single measure the attributes of migraine pharmacotherapy that patients consider most important: rapid and sustained pain-free response with no side-effects. Using pooled data from two replicate randomized, double-blind, parallel-group, placebo-controlled studies, this post hoc analysis compared the fixed-dose combination tablet sumatriptan/naproxen sodium (n = 726) with sumatriptan monotherapy (n = 723), naproxen sodium monotherapy (n = 720), and placebo (n = 742) with respect to sustained pain-free/no adverse events and closely related composite measures. Sustained pain-free/no adverse events was defined as having both a sustained pain-free response from 2 through 24 hours post-dose with no use of rescue medication and having no adverse events within up to 5 days after dosing with study medication. The percentage of patients with sustained pain-free/no adverse events was 16% with sumatriptan/naproxen sodium compared with 11%, 9% and 7% for sumatriptan, naproxen sodium and placebo, respectively (p<0.01 sumatriptan/naproxen sodium versus each other treatment). Sumatriptan/naproxen sodium was also significantly more effective than sumatriptan, naproxen sodium, and placebo for other composite endpoints including the percentages of patients with (1) sustained pain-free/no adverse events within 1 day; (2) sustained pain-free/no drug-related adverse events within up to 5 days; (3) sustained pain-free/no drug-related adverse events within 1 day; (4) sustained pain relief/no adverse events within up to 5 days; and (5) sustained pain relief/no adverse events within 1 day. The results demonstrate the superiority of sumatriptan/naproxen sodium to sumatriptan monotherapy, naproxen sodium monotherapy and placebo with respect to the rigorous and clinically relevant endpoint of sustained pain-free/no adverse events and reinforce the usefulness of utilizing this new composite endpoint.

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.

Almotriptan in triptan-naïve patients: new evidence of benefits

Although triptans represent the standard of care for migraine that is severe, disabling and/or suboptimally responsive to migraine non-specific analgesia, they are often underused in clinical practice. Simple analgesics and non-steroidal anti-inflammatory drugs (NSAIDs) may provide effective treatment in some patients, but it is an inadequate response to these drugs that drives the therapeutic progression to triptans at the end of the traditional 'step-care' approach. However, there are several disadvantages to this approach. It may cause patients to lose confidence in their physician during this hierarchical 'trial-and-error' search for optimal treatment when prescribed medications are ineffective, leading them to cease consulting before triptans are tried. It may also result in a protracted time interval of suboptimal treatment, with unnecessary suffering in patients who are triptan candidates. The alternative approach of 'stratified care', in which medication is prescribed according to the severity of symptoms, enables triptans to be used earlier in the treatment plan, especially when triptan candidates are given a choice between simple analgesic/NSAID and triptan medication from the start. This raises the question about the efficacy of triptans in triptan-naïve (TN) patients. A recent exploratory post-hoc analysis compared the effect of almotriptan 12.5 mg in TN patients (n = 342) with that in triptan-experienced patients (n = 237). Almotriptan was effective in both cohorts with a consistent trend in favour of the efficacy of almotriptan in TN patients, notably for sustained pain freedom (SPF) and SPF plus no adverse events. Moreover, both headache recurrence at 24 h and the use of rescue medication was lower in the TN patients, whereas tolerability was equally good in both cohorts. These findings indicate that TN patients can expect excellent symptom control when they progress from non-specific analgesia to treatment with almotriptan and support the earlier use of triptans in line with the stratified care paradigm.

Genetic disruption of both tryptophan hydroxylase genes dramatically reduces serotonin and affects behavior in models sensitive to antidepressants

The neurotransmitter serotonin (5-HT) plays an important role in both the peripheral and central nervous systems. The biosynthesis of serotonin is regulated by two rate-limiting enzymes, tryptophan hydroxylase-1 and -2 (TPH1 and TPH2). We used a gene-targeting approach to generate mice with selective and complete elimination of the two known TPH isoforms. This resulted in dramatically reduced central 5-HT levels in Tph2 knockout (TPH2KO) and Tph1/Tph2 double knockout (DKO) mice; and substantially reduced peripheral 5-HT levels in DKO, but not TPH2KO mice. Therefore, differential expression of the two isoforms of TPH was reflected in corresponding depletion of 5-HT content in the brain and periphery. Surprisingly, despite the prominent and evolutionarily ancient role that 5-HT plays in both vertebrate and invertebrate physiology, none of these mutations resulted in an overt phenotype. TPH2KO and DKO mice were viable and normal in appearance. Behavioral alterations in assays with predictive validity for antidepressants were among the very few phenotypes uncovered. These behavioral changes were subtle in the TPH2KO mice; they were enhanced in the DKO mice. Herein, we confirm findings from prior descriptions of TPH1 knockout mice and present the first reported phenotypic evaluations of Tph2 and Tph1/Tph2 knockout mice. The behavioral effects observed in the TPH2 KO and DKO mice strongly confirm the role of 5-HT and its synthetic enzymes in the etiology and treatment of affective disorders.

Applying the benefits of the AwM Study in the clinic

The Act when Mild (AwM) Study has illustrated the benefits to migraineurs of taking triptan medication when their migraine pain is still mild and within 1 h of the onset of symptoms. Yet many patients wait until the attack has fully developed before taking their medication, with potentially inferior outcomes. In order to reproduce the benefits of early intervention using the AwM paradigm in daily practice, a number of key barriers need to be addressed at both the physician and patient level. Notable physician-related barriers to be overcome, particularly at the primary care level, include accuracy of an early diagnosis of migraine in newly presenting patients, communication skills that generate a therapeutic engagement with migraine patients and enhance patient confidence, the application of knowledge about up-to-date strategies to optimize treatment outcomes, and the setting of achievable goals to avoid unrealistic expectations. Patient-related obstacles that need to be identified and overcome encompass patient attitude, expectations, and behaviour. Migraine patients may be reluctant to consult their physician, and, of those who do, many stop consulting because they perceive that physicians can do little to improve their situation. For this reason, migraine patients need to be counselled about the most appropriate medication for their level of symptoms. Moreover, patients need to be confident before they will adhere routinely to the advice they receive, and high in the priority of advice is the use of medication, particularly triptans, at the first sign of a migraine attack, rather than waiting until their attack has progressed to moderate or severe intensity. Patients who adhere to this advice are likely to experience a notable reduction in the pain, disability and time lost that they would otherwise suffer. The beneficial effects of early triptan intervention illustrated in the AwM Study can therefore be best reproduced in the clinic if the correct advice given to patients is not only accepted and applied by them, but also followed up by their physician.

Pathways to the Best Fit of Triptans for Migraine Patients

Variability in drug response is a major barrier to the successful treatment of migraine, and most treatments are only optimal in a subset of patients. Although triptans provide the best therapeutic option for the treatment of acute migraine, it has not previously been possible to predict how well patients will respond to a specific triptan or whether they will experience unpleasant adverse events. Hence, it has been difficult for physicians to match individual patients with the most suitable agent to treat their migraine pain. Intrapatient variability has been associated with polymorphisms in genes encoding drug-metabolizing enzymes, drug transporters and drug targets. Pharmacogenetics provides the possibility of tailoring the therapeutic approach to individual patients, in order to maximize treatment efficacy while minimizing the potential for unwanted side-effects. This review demonstrates how almotriptan may overcome genetically determined responses by utilizing diverse metabolic pathways to provide therapeutic benefit to many migraineurs.

Meeting patient expectations in migraine treatment: what are the key endpoints?

Clinical outcomes of migraine treatment are generally based on two major endpoints: acute pain resolution and effects on quality of life (QOL). Resolution of acute pain can be evaluated in a number of ways, each increasingly challenging to achieve; pain relief, pain freedom at 2 h, sustained pain-freedom, and SPF plus no adverse events (SNAE, the most challenging). QOL questionnaires help assess the burden of migraine and identify optimal treatments. Pain resolution and improved QOL form the basis of the ultimate target—meeting patient expectations, to achieve patient satisfaction. To achieve this, it is crucial to choose appropriate endpoints that reflect realistic treatment goals for individual patients. Moreover, SNAE can help discriminate between triptans, with almotriptan having the highest SNAE score. Kaplan–Meier plots are also relevant when evaluating migraine treatments. The use of symptomatic medication may lead to the paradoxical development of medication-overuse headache. In general practice, patients should use simple tools for pain measurement (e.g. headache diary) and a QOL questionnaire. A composite endpoint of pain resolution and QOL restoration would constitute a step forward in migraine management.

Pharmacogenetics of migraine: genetic variants and their potential role in migraine therapy

Migraine is a paroxysmal neurological disorder affecting up to 6% of males and 18% of females in the general population, and has been demonstrated to have a strong, but complex, genetic component. Genetic investigation of migraine provides hope that new targets for medications and individual specific therapy will be developed. The identification of polymorphisms or genetic biomarkers for disease susceptibility and treatment should aid in providing a better understanding of migraine pathology and, consequently, more appropriate and efficient treatment for migraineurs. In this review, we will discuss results investigating genetic biomarkers for migraine and their potential role in future therapy planning.