Efficacy and Safety of MAP0004, Orally Inhaled DHE in Treating Migraines With and Without Allodynia

Dihydroergotamine protects against ischemic stroke by modulating microglial/macrophage polarization and inhibiting inflammation in mice

OBJECTIVES

The search for drugs that can protect the brain tissue and reduce nerve damage in acute ischemic stroke has emerged as a research hotspot. We investigated the potential protective effects and mechanisms of action of dihydroergotamine against ischemic stroke.

METHODS

C57BL/6 mice were subjected to middle cerebral artery occlusion (MCAO), and dihydroergotamine at a dose of 10 mg/kg/day was intraperitoneally injected for 14 days. Adhesive removal and beam walking tests were conducted 1, 3, 5, 7, 10, and 14 days after MCAO surgery. Thereafter, the mechanism by which dihydroergotamine regulates microglia/macrophage polarization and inflammation and imparts ischemic stroke protection was studied using enzyme-linked immunosorbent assay, immunofluorescence staining, and western blotting.

RESULTS

From the perspective of a drug repurposing strategy, dihydroergotamine was found to inhibit oxygen-glucose deprivation damage to neurons, significantly improve cell survival rate, and likely exert a protective effect on ischemic brain injury. Dihydroergotamine significantly improved neural function scores and survival rates and reduced brain injury severity in mice. Furthermore, dihydroergotamine manifests its protective effect on ischemic brain injury by reducing the expression of TNF-α and IL-1β in mouse ischemic brain tissue, inhibiting the polarization of microglia/macrophage toward the M1 phenotype and promoting polarization toward the M2 phenotype.

CONCLUSION

This study is the first to demonstrate the protective effect of dihydroergotamine, a first-line treatment for migraine, against ischemic nerve injury in vitro and in vivo.

Variability in recurrence rates with acute treatments for migraine: why recurrence is not an appropriate outcome measure

BACKGROUND

Headache recurrence is a common feature of acute therapies, whether approved or still in development, and continues to be a significant problem for both the patient and the clinician. Further complicating this issue is lack of standardization in definitions of recurrence used in clinical trials, as well as disparity in patient characteristics, rendering a comparison of different acute medications challenging. Recurrence has serious clinical implications, which can include an increased risk for new-onset chronic migraine and/or development of medication overuse headache. The aim of this review is to illustrate variability of recurrence rates depending on prevailing definitions in the literature for widely used acute treatments for migraine and to emphasize sustained response as a clinically relevant endpoint for measuring prolonged efficacy. BODY: A literature search of PubMed for articles of approved acute therapies for migraine that reported recurrence rates was performed. Study drugs of interest included select triptans, gepants, lasmiditan, and dihydroergotamine mesylate. An unpublished post hoc analysis of an investigational dihydroergotamine mesylate product that evaluated recurrence rates using several different definitions of recurrence common in the literature is also included. Depending on the criteria established by the clinical trial and the definition of recurrence used, rates of recurrence vary considerably across different acute therapies for migraine, making it difficult to compare results of different trials to assess the sustained (i.e., over a single attack) and the prolonged (i.e., over multiple attacks) efficacy of a particular study medication.

CONCLUSION

A standardized definition of recurrence is necessary to help physicians evaluate recurrence rates of different abortive agents for migraine. Sustained pain relief or freedom may be more comprehensive efficacy outcome measures than recurrence. Future efficacy studies should be encouraged to use the recommended definition of sustained pain freedom set by the International Headache Society.

Recent advances in drug delivery to the central nervous system by inhalation

INTRODUCTION

Drugs need to enter the systemic circulation efficiently before they can cross the blood-brain barrier and reach the central nervous system. Although the respiratory tract is not a common route of administration for delivering drugs to the central nervous system, it has attracted increasing interest in recent years for this purpose.

AREAS COVERED

In this article, we compare pulmonary delivery to three other common routes (parenteral, oral, and intranasal) for delivering drugs to the central nervous system, followed by summarising the devices used to aerosolise neurological drugs. Recent studies delivering drugs for different neurological disorders via inhalation are then discussed to illustrate the strengths of pulmonary delivery.

EXPERT OPINION

Recent studies provide strong evidence and rationale to support inhaling neurological drugs. Since inhalation can achieve improved pharmacokinetics and rapid onset of action for multiple drugs, it is a non-invasive and efficient method to deliver drugs to the central nervous system. Future research should focus on delivering other small and macro-molecules via the lungs for different neurological conditions.

STOP 301: A Phase 3, open-label study of safety, tolerability, and exploratory efficacy of INP104, Precision Olfactory Delivery (POD® ) of dihydroergotamine mesylate, over 24/52 weeks in acute treatment of migraine attacks in adult patients

Objective

To report the safety, tolerability, exploratory efficacy, and patient acceptability of INP104 for the acute treatment of migraine from the Phase 3 STOP 301 trial.

Background

Dihydroergotamine (DHE) has long been used to treat migraine, but intravenous administration is invasive, frequently associated with adverse events (AEs), and not suitable for at‐home administration. INP104 is an investigational drug device that delivers DHE mesylate to the upper nasal space using a Precision Olfactory Delivery technology and was developed to overcome the shortcomings of available DHE products.

Methods

STOP 301 was an open‐label, 24‐week safety study, with a 28‐week extension period. After a 28‐day screening period where patients used their “best usual care” to treat migraine attacks, patients were given INP104 (1.45 mg) to self‐administer nasally with self‐recognized attacks. The primary objective of this study was to assess safety and tolerability, with a specific focus on nasal mucosa and olfactory function. Exploratory objectives included efficacy assessments of migraine measures and a patient acceptability questionnaire.

Results

A total of 360 patients entered the 24‐week treatment period, with 354 patients dosing at least once. INP104‐related treatment‐emergent AEs were reported by 36.7% (130/354) of patients, and 6.8% (24/354) discontinued treatment due to AEs over 24 weeks. No new safety signals were observed following delivery to the upper nasal space. Pain freedom, the most bothersome symptom freedom, and pain relief at 2 h post‐INP104 were self‐reported by 38.0% (126/332), 52.1% (173/332), and 66.3% (167/252) of patients, respectively. A low recurrence rate at 24 and 48 h was observed (7.1% [9/126] and 14.3% [18/126], respectively). Most patients found INP104 easy to use and preferred it over their current therapy.

Conclusions

INP104 has the potential to deliver rapid symptom relief, without injection, that is well tolerated and suitable for outpatient use. Results suggest INP104 may be a promising treatment for patients with migraine.

Acute Migraine Treatment

PURPOSE OF REVIEW

Migraine is a disabling disease of attacks of moderate to severe pain with associated symptoms. Every person with migraine requires treatment for acute attacks. Treatments can range from behavioral management and nonspecific medications to migraine-specific medications and neuromodulation. For many with migraine, having a combination of tools allows for effective treatment of all types of attacks.

RECENT FINDINGS

Over the past several years, four neuromodulation devices have been cleared by the US Food and Drug Administration (FDA) for treatment of acute migraine, and three medications with novel mechanisms of action have been FDA approved. They add to the arsenal available to people with migraine and focus on migraine-specific pathways to allow for precise care with fewer side effects.

SUMMARY

This article discusses acute migraine therapy, focusing on best-level evidence.

Dihydroergotamine (DHE) - Then and Now: A Narrative Review

OBJECTIVE

To provide a narrative review of clinical development programs for non-oral, non-injectable formulations of dihydroergotamine (DHE) for the treatment of migraine.

BACKGROUND

Dihydroergotamine was one of the first "synthetic drugs" developed in the 20th century for treating migraine. It is effective and recommended for acute migraine treatment. Since oral DHE is extensively metabolized, it must be given by a non-oral route. Intravenous DHE requires healthcare personnel to administer, subcutaneous/intramuscular injection is challenging to self-administer, and the approved nasal spray formulation exhibits low bioavailability and high variability that limits its efficacy. Currently there are several attempts underway to develop non-oral, non-injected formulations of DHE.

METHOD

A systematic search of MEDLINE/PubMed and ClinicalTrials.gov databases, then narrative review of identified reports, focusing on those published in the last 10 years.

RESULTS

Of 1881 references to DHE from a MEDLINE/PubMed search, 164 were from the last 10 years and were the focus of this review. Further cross reference was made to ClinicalTrials.gov for 19 clinical studies, of which some results have not yet been published, or are studies that are currently underway. Three nasal DHE products are in clinical development, reawakening interest in this route of delivery for migraine. Other routes of DHE administration have been, or are being, explored.

CONCLUSION

There is renewed appreciation for DHE and the need for non-oral, non-injected delivery is now being addressed.

The discovery and development of inhaled therapeutics for migraine

INTRODUCTION

Migraine is a disabling primary headache disorder that requires effective treatments. Inhalation is currently being explored for the delivery of drugs for migraine. Pulmonary-route delivery of drugs shows potential advantages for its use as a treatment, particularly compared the oral route. Areas covered: The authors highlight the current state of the literature and review multiple therapies for migraine-utilizing inhalation as the route of administration. The following therapeutics are discussed: inhaled ergotamine, inhaled dihydroergotamine mesylate (MAP0004), inhaled prochlorperazine, and inhaled loxapine. Coverage is also given to normobaric oxygen, hyperbaric oxygen, and nitrous oxide therapies. Expert opinion: Inhalation of MAP0004 showed promising results in terms of efficacy for acute migraine treatment in phase 3 studies, together with a more favorable tolerability profile compared to parenteral dosing and a better pharmacokinetic profile versus oral or intranasal delivery. In phase 2 trials, inhaled prochlorperazine shows good pharmacokinetics and efficacy, in contrast to inhaled loxapine that did not provide encouraging results in terms of efficacy. The authors see the potential for the use of dihydroergotamine mesylate in clinical practice pending regulatory approval.

New strategies for the treatment and prevention of primary headache disorders

The primary headache disorders, which include migraine, cluster headache and tension-type headache, are among the most common diseases and leading causes of disability worldwide. The available treatment options for primary headache disorders have unsatisfactory rates of efficacy, tolerability and patient adherence. In this Review, we discuss promising new approaches for the prevention of primary headache disorders, such as monoclonal antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor, and small-molecule CGRP receptor antagonists. Neuromodulation approaches employing noninvasive or implantable devices also show promise for treating primary headache disorders. Noninvasive treatments, such as transcranial magnetic stimulation and transcutaneous peripheral nerve stimulation, are delivered by devices that patients can self-administer. Implantable devices targeting the occipital nerves, sphenopalatine ganglion or high cervical spinal cord are placed using percutaneous and/or surgical procedures, and are powered either wirelessly or by surgically implanted batteries. These new and emerging treatments have the potential to address unmet patient needs and reduce headache-associated disability.

Orally inhaled migraine therapy: Where are we now?

Migraine is a debilitating disease that affects 9% of men and 19% of women worldwide with high socio-economic and personal impact. Surveys indicate that migraineurs are among the most dissatisfied with available therapeutic options, predominantly given via oral or injectable routes, citing side effects as the primary complaint. Orally inhaled therapies have the potential to offer faster onset of action with fewer side effects compared to existing therapies, yet development has stalled. Despite emerging therapies such as calcitonin gene-related peptide antagonists, there are still good opportunities for repositioning migraine drugs via the inhaled route.

A Randomized Trial of Ketorolac vs. Sumatripan vs. Placebo Nasal Spray (KSPN) for Acute Migraine

OBJECTIVE

To compare the efficacy of ketorolac nasal spray (NS) vs. placebo and sumatriptan NS for the acute treatment of migraine.

METHODS

This was a randomized, double-blind, placebo and active-comparator, crossover study. Adult migraineurs were randomized to ketorolac NS 31.5 mg, sumatriptan NS 20 mg, or placebo to treat three moderate to severe migraine attacks and switched treatments with each attack. Patients seeking headache care at a headache center or in response to community advertisement were recruited. Adult participants with episodic migraine who experienced ≥2 migraine attacks per month were eligible for the Ketorolac vs. Sumatriptan vs. Placebo Nasal Spray migraine study. Participants were randomized to treatment arms by a research pharmacist, in a 1:1:1 ratio using computer-generated lists. The primary outcome was 2-hour pain relief. Secondary outcomes included 2-hour pain freedom and absence of migraine associated symptoms, and 24-hour sustained pain relief and pain freedom.

RESULTS

Of the 72 randomized participants, 54 (75%) treated at least one attack and 49 (68%) completed all three treatments, for a total of 152 treated migraine attacks. Both ketorolac NS (72.5%, P < .001) and sumatriptan NS (69.4%, P = .001) were more effective than placebo (38.3%) for 2-hour pain relief and 2-hour pain freedom (ketorolac: 43.1%, P = .004; sumatriptan: 36.7%, P = .046; placebo: 18.4%). Ketorolac NS, but not sumatriptan NS, was more effective than placebo in 2-hour absence of nausea. Both ketorolac NS and sumatriptan NS were more effective than placebo for 24-hour sustained pain relief (ketorolac: 49%, P < .001; sumatriptan: 31%, P = .01, placebo: 20%). Only ketorolac NS was superior to placebo for 24-hour (ketorolac: 35.3%, P = .003; sumatriptan: 22.4%, P = .18, placebo: 12.2%) sustained pain freedom. Nasal burning and dysgeusia were the most common adverse effects for active treatments.

CONCLUSIONS

This study supports that ketorolac NS is superior to placebo and that it is non-inferior to sumatriptan NS for the acute abortive treatment of migraine.

New treatments for headache

Migraine and cluster headache are primary headache disorders commonly encountered in clinical practice. Despite the profound disability caused by these primary headache disorders, available acute and preventive treatment options are limited. Recent understanding of headache pathophysiology has led to the development of new drug formulations and novel drug targets that are extremely promising. This article will highlight several of the new treatments that are currently under investigation including novel delivery mechanisms of already existing medications, calcitonin gene-related peptide (CGRP) receptor antagonists, antibodies to CGRP and its receptor, serotonin receptor agonists, transient receptor potential vanilloid receptor modulators, orexin receptor antagonists, glial cell modulators, and neuromodulation. If data is supportive, these therapies will be welcome additions to the headache specialist's armamentarium.

Gabapentin inhibits central sensitization during migraine

Peripheral and central sensitizations are phenomena that occur during migraine. The role of pentin, a migraine preventive drug, on central sensitization remains unclear. In this study, a rat model of migraine was established by electrical stimulation of the trigeminal ganglion, and the an-imals were given intragastric gabapentin. Changes in amino acid content in the cerebrospinal fluid and protein kinase C membrane translocation in the spinal trigeminal nucleus were examined to clarify the mechanisms underlying the efficacy of gabapentin in the treatment of central sensitization during migraine. Electrophysiology, liquid chromatography-mass spectrometry and western blot analysis results revealed that gabapentin reduces neuronal excitability in the spinal nucleus in the trigeminal nerve, decreases excitatory amino acid content and inhibits the activation of protein ki-nase C. This provides evidence that excitatory amino acids and protein kinase C are involved in the formation and maintenance of central sensitization during migraine. Gabapentin inhibits migraine by reducing excitatory amino acid content in the cerebrospinal fluid and inhibiting protein kinase C ac-tivation.

Dihydroergotamine and sumatriptan in isolated human coronary artery, middle meningeal artery and saphenous vein

BACKGROUND

Dihydroergotamine (DHE) and sumatriptan are contraindicated in patients with cardiovascular disease because of their vasoconstricting properties, which have originally been explored in proximal coronary arteries. Our aim was to investigate DHE and sumatriptan in the proximal and distal coronary artery, middle meningeal artery and saphenous vein.

METHODS

Blood vessel segments were mounted in organ baths and concentration response curves for DHE and sumatriptan were constructed.

RESULTS

In the proximal coronary artery, meningeal artery and saphenous vein, maximal contractions to DHE (proximal: 8 ± 4%; meningeal: 32 ± 7%; saphenous: 52 ± 11%) and sumatriptan (proximal: 17 ± 7%; meningeal: 61 ± 18%, saphenous: 37 ± 8%) were not significantly different. In the distal coronary artery, contractions to DHE (5 ± 2%) were significantly smaller than those to sumatriptan (17 ± 9%). At clinically relevant concentrations, mean contractions to DHE and sumatriptan were below 3% in proximal coronary arteries and below 6% in distal coronary arteries. Contractions in the meningeal artery and saphenous vein were higher (7%-38%).

CONCLUSIONS

Contractions to DHE in distal coronary arteries are smaller than those to sumatriptan, while at clinical concentrations they both induce only slight contractions. In meningeal arteries contractions to DHE and sumatriptan are significantly larger, showing their cranioselectivity. Contractions to DHE in the saphenous vein are higher than those in the arteries, confirming its venous contractile properties.

The pipeline in headache therapy

Migraine is a common, disabling, neurovascular disorder characterized by episodic attacks of head pain and associated disability plus systemic autonomic and neurologic symptoms. The advent of the triptan class of medication in the 1990s revolutionized the acute treatment of migraine, but many migraineurs do not respond optimally or at all to triptans, have intolerable adverse effects, or have contraindications to their use. Preventive pharmacotherapy has advanced mostly through serendipity, with new drugs being found effective while being used for other indications. There remains a significant need for new medications and devices that can provide effective, rapid, and sustained pain relief without adverse effects or recurrence. Several new acute and preventive therapies for the treatment of migraine and cluster headaches have shown promise and are currently under investigation. This article covers innovative delivery mechanisms, calcitonin gene-related peptide receptor antagonists, antibodies to calcitonin gene-related peptide and its receptor, 5-HT1F receptor agonists, transient receptor potential vanilloid receptor modulators, orexin receptor antagonists, glial cell modulators, and neurostimulation.

Activation of 5-hydroxytryptamine1B/1D/1F receptors as a mechanism of action of antimigraine drugs

INTRODUCTION

The introduction of the triptans (5-hydroxytryptamine (5-HT)1B/1D receptor agonists) was a great improvement in the acute treatment of migraine. However, shortcomings of the triptans have prompted research on novel serotonergic targets for the treatment of migraine.

AREAS COVERED

In this review the different types of antimigraine drugs acting at 5-HT receptors, their discovery and development are discussed. The first specific antimigraine drugs were the ergot alkaloids, consisting of ergotamine, dihydroergotamine and methysergide, which are agonists at 5-HT receptors, but can also bind α-adrenoceptors and dopamine receptors. In the 1990s, the triptans became available on the market. They are 5-HT1B/1D receptor agonists, showing fewer side effects due to their receptor specificity. In the last years, compounds that bind specifically to 5-HT1D, 5-HT1F and 5-HT7 receptors have been explored for their antimigraine potential. Furthermore, the serotonergic system seems to act in tight connection with the glutamatergic as well as the CGRP-ergic systems, which may open novel therapeutic avenues.

EXPERT OPINION

Although the triptans are very effective in treating migraine attacks, their shortcomings have stimulated the search for novel drugs. Currently, the focus is on 5-HT1F receptor agonists, which seem devoid of vascular side effects. Moreover, novel compounds that affect multiple transmitter and/or neuropeptide systems that are involved in migraine could be of therapeutic relevance.

Management of acute and chronic migraine

PURPOSE OF REVIEW

We highlight the recent clinical trials for the management of acute and chronic migraine.

RECENT FINDINGS

In women with menstrual migraine, triptans seem to be well tolerated irrespective of whether or not patients are taking oestrogen-containing contraceptives or have comorbidities that indicate increased cardiovascular risk. The new acute drug, telcagepant, a calcitonin gene-related peptide (CGRP) antagonist, is safe for long-term use (up to 18 months) in migraine patients with stable coronary artery disease in whom the use of triptans is not advisable. From the pooled analysis of the two Phase III Research Evaluating Migraine Prophylaxis Therapy studies of onabotulinumtoxinA (BOTOX) in chronic migraineurs, it clearly emerged that efficacy increases overtime (up to 56 weeks) and paralleled self-perceived improvement in quality of life. Effectiveness was also observed in patients with severely disabling headaches, who met criteria for triptan abuse and were refractory to several prophylactic treatments. Finally, combination of preventive pharmacological agents with different action mechanisms may be the next frontier in therapeutic advancements for treating migraine.

SUMMARY

Although triptans are safe and well tolerated, CGRP antagonists may be an option for nonresponsive patients or those in whom the use of triptans is not advisable. New drugs and combinations of old therapeutic options may help patients with severe forms of headache.