Randomized, double-blind, placebo-controlled study of the safety, tolerability and pharmacokinetics of MAP0004 (orally-inhaled DHE) in adult asthmatics

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.

Assessing acute systemic effects of an inhaled drug with serial echocardiography: a placebo-controlled comparison of inhaled and intravenous dihydroergotamine

Objective

MAP0004 is an investigational product which delivers dihydroergotamine (DHE) through the lung via a breath-synchronized metered dose inhaler. The objective of this study was to compare the acute effects of orally inhaled and intravenous (IV) DHE to placebo on maximum change and area under the curve for pulmonary arterial systolic pressure (PASP).

Research design and methods

A randomized, double-blind, placebo-controlled, 3-period, crossover study of 24 health adults. Trial registration NCT01089062. Study assessments included pharmacokinetics, electrocardiograms (ECG), and validated echocardiographic (Doppler)-derived measures of PASP by echocardiogram. The primary endpoint was the absolute change in calculated PASP using area under the curve, 0 to 2 hours (AUC_0–2h).

Results

The change in PASP with IV DHE was significantly different than MAP0004 and placebo (AUC_0–2h2857, 2624, and 2453 mmHg*min, respectively). After a second dose of MAP0004, AUC_0–4h remained lower with MAP0004 than with a single dose of IV DHE. Adverse events were more common with IV DHE than with MAP0004 or placebo. None of the treatments produced clinically significant changes in PASP or other cardiac parameters. Changes in PASP were significantly smaller with MAP0004 compared with IV DHE.

Conclusion

These results indicate the effects 1 mg of orally inhaled DHE on the cardiovascular system are less than with 1 mg of IV DHE, and that serial echocardiography can be a useful noninvasive means of assessing acute systemic effects.

Effects of a supratherapeutic dose of investigational orally inhaled dihydroergotamine (MAP0004) on QT interval: a randomized, double-blind, active- and placebo-controlled crossover study in healthy volunteers

BACKGROUND

MAP0004 is an orally inhaled investigational drug containing dihydroergotamine (DHE). Although DHE has been used for 60 years with no reported cardiac arrhythmias, a thorough QT study had not previously been performed with DHE.

OBJECTIVE

The objective of this study was to assess the effects of MAP0004 on the QT interval as required for regulatory approval of a new product.

METHODS

This randomized, double-blind, placebo-controlled, 3-period crossover study enrolled healthy volunteers. Subjects were assigned to receive, in randomized sequence, MAP0004 at a supratherapeutic dose (3-fold the clinically effective dose) (3.0 mg), moxifloxacin 400 mg, or inactive vehicle, each administered with 1 placebo capsule. Triplicate ECGs were performed continuously at baseline (day 0), before dosing, and over 24 hours after dosing in each treatment period. The effect on the QT interval was assessed using the Fridericia (QTcF) and individualized (QTcI) correction formulas.

RESULTS

Fifty-four healthy adults (20 men, 34 women; mean age, 28 years) completed the trial and had measurable plasma levels of DHE after MAP0004 administration. The largest observed mean difference in QTcI between MAP0004 and placebo was 0.08 msec, and the largest 1-sided 95% upper confidence bound was 2.24 msec, both at 30 minutes after dosing. In contrast, moxifloxacin increased the mean QTcI between 9.57 and 11.28 msec relative to placebo, with a 1-sided lower 95% CL between 7.23 and 8.96 msec, confirming that the assay sensitivity was sufficient to detect MAP0004-related effects. Nausea (27.8%) was common following MAP0004 administration but apparently did not influence the QTc interval.

CONCLUSIONS

A supratherapeutic dose of MAP0004 was not associated with prolonged QTc intervals. At the proposed clinical dose (1.0 mg), MAP0004 is unlikely to affect the QT interval. MAP0004 and its primary metabolite showed no evidence for prolongation of the QTc interval in healthy subjects according to the criteria required from regulatory agencies. ClinicalTrials.gov identifier: NCT01191723.

Lack of drug interaction between the migraine drug MAP0004 (orally inhaled dihydroergotamine) and a CYP3A4 inhibitor in humans

BACKGROUND

Dihydroergotamine (DHE), a proven migraine treatment, currently has product labeling warning against concomitant use of CYP3A4 inhibitors because of potential drug interactions. However, no reported studies of such interactions with DHE administered by any route are available.

METHODS

The pharmacokinetics (PK) of MAP0004, an investigative inhaled DHE formulation, were assessed in human subjects with and without CYP3A4 inhibition by ketoconazole to evaluate the potential for drug interaction, elevation of DHE levels, and increased adverse effects.

RESULTS

After MAP0004 alone vs. MAP0004 plus ketoconazole, the DHE maximum concentrations (C(max)) and area-under-the-curve (AUC(0-48) and AUC(0-∞)) were not statistically significantly different nor was the C(max) of the primary metabolite, 8'-OH-DHE. A difference in 8'-OH-DHE AUCs was observed between MAP0004 with and without ketoconazole; however, the concentrations were very low. MAP0004 was well tolerated after both treatments.

CONCLUSIONS

This study demonstrated that CYP3A4 inhibition had little to no effect on DHE PK after MAP0004 administration, apparently because of its high systemic and low gastrointestinal bioavailability. CYP3A4 inhibition slowed elimination of the metabolite 8'-OH-DHE, but concentrations were too low to be pharmacologically relevant.

Pulmonary delivery of therapeutic compounds for treating CNS disorders

Delivering therapeutic compounds via the lungs presents potential advantages relative to other routes of administration. Depending on the compound and the disease state, these advantages may include: non-invasive medication delivery, ease of administration, higher bioavailability leading to dose sparing and lower systemic toxicity, potentially greater blood–brain barrier penetration and rapid pharmacodynamic effect. The practice of inhaling drugs has been around for centuries, including both medical and recreational usage. It is only more recently that formal clinical development programs have been undertaken specifically to use medication delivery via the lung to achieve systemic blood levels for the treatment of CNS disorders. At present, there are several CNS therapies being developed for pulmonary administration, with some of those programs at or near the marketing authorization stage. While there are still regulatory hurdles before these therapies can be put into practice, the success of these programs thus far demonstrates the scientific viability of inhalation therapies for treating CNS disorders.

Orally inhaled dihydroergotamine: reviving and improving a classic

Migraine pathophysiology continues to evolve, and additional therapeutic receptors influencing unrecognized neural networks within the cortex, brainstem and cerebral vasculature likely exist. Following the advent of the triptans, the use of dihydroergotamine (DHE) declined, because of the ease of use and improved side effect profiles of triptans. However, there remain many patients who respond poorly to triptans, yet respond significantly better to DHE. This may be due to the broader neuroreceptor targets that DHE interacts with, as opposed to the selective receptor activity of the triptans. Unfortunately, DHE is still infrequently utilized compared with other acute treatments such as triptans, primarily because of difficulty in administration and physician unfamiliarity and inexperience with its use. However, the new orally inhaled DHE appears to be as effective with a better side effect profile compared with intravenous DHE, thus eliminating the complexities typically associated with DHE administration.

Toxicological assessment of dihydroergotamine after chronic inhalation in dogs

The objective was to determine the respiratory toxicity of MAP0004, orally inhaled dihydroergotamine (DHE), via inhalation for six months. Forty beagle dogs (twenty females, twenty males) were treated by nose-only inhalation for 182 days. Groups 2 through 5 received MAP0004 (mean doses: 0.045, 0.154, 0.44, 0.825 mg/kg); Group 1 received vehicle only. Groups 1 through 4 received single thirty-minute exposures, whereas Group 5 was exposed twice daily for thirty minutes. Toxicity was assessed from clinical observations, objective evaluations, and clinical and anatomical pathology. Systemic effects were scabbing of ear tips in Groups 3, 4, and 5 and excessive salivation and emesis, observed in Group 5. No changes were observed in the lungs in any dose group. Minimal treatment-related microscopic changes were observed in the respiratory nasal epithelium only in Group 5. No plexiform, vascular media, or fibroproliferative changes in any heart valves were observed in any group. Expected systemic pharmacologic effects were observed only at MAP0004 target doses ≥ 0.224 mg/kg (achieved doses > 0.154 mg/kg), which was more than five times the maximum daily intravenous (IV) human clinical dose of DHE, and more than twenty times the systemic equivalent dose of MAP0004. The no-observed adverse effect level (NOAEL) was the achieved inhaled dose of 0.045 mg/kg, or four times the human clinical dose of MAP0004.

Where is dihydroergotamine mesylate in the changing landscape of migraine therapy?

IMPORTANCE OF THE FIELD

Migraine affects approximately 18% of women and 6% of men, and has an immense impact on quality of life and productivity. Advancement in therapeutic options has been slow. For many patients with difficult-to-treat migraine, the appropriate use of dihydroergotamine mesylate (DHE) can result in treatment success and unprecedented patient satisfaction.

AREAS COVERED IN THIS REVIEW

Migraine treatment guidelines regarding the role of DHE are highlighted. An overview of the market for antimigraine drugs is provided in the context of DHE, since its introduction in 1943, and the novel agents that are likely to be available in the near future. An extensive literature search was undertaken using Medline and the Cochrane Systematic Review and Clinical Trial databases.

WHAT THE READER WILL GAIN

An understanding of which migraine patients are likely to benefit maximally from treatment with DHE in its various forms.

TAKE HOME MESSAGE

In the most difficult patient groups - including those with status migrainosus, migraine recurrence, medication-overuse headache, and chronic daily headache - DHE has therapeutic efficacy superior to other agents. The side-effect profile of DHE is more benign than is often perceived and should not be a deterrent for use in well-chosen cases.

Revisiting the role of ergots in the treatment of migraine and headache

The harmful side effects of the ergots described by early civilizations have been overcome with efficacious treatment for headaches including migraine, cluster, and chronic daily headache. Use of ergots contributed to initial theories of migraine pathogenesis and provided the substrate for development of the triptans. Triptans are very efficacious for many migraineurs, and since their widespread use, use of ergots has significantly declined. Unfortunately, there remain many migraineurs who benefit little from triptans, yet respond very well to ergots. Discoveries in migraine pathophysiology have given us better understanding of the complex processes involved, although there remain many unknown factors in migraine treatment. Additional, unrecognized therapeutic targets may exist throughout the neuronal connections of the brainstem, cortex, and cerebral vasculature. Ergots interact with a broader spectrum of receptors than triptans. This lack of receptor specificity explains potential ergot side effects, but may also account for efficacy. The role of ergots in headache should be revisited, especially in view of newer ergot formulations with improved tolerability and side effect profiles, such as orally inhaled dihydroergotamine. Redefining where in the headache treatment spectrum ergots belong and deciding when they may be the optimal choice of treatment is necessary.

New drugs for migraine

After the triptans, a calcitonin gene-related peptide blocker (telcagepant) is the first acute medicine that has been developed primarily for treatment of acute migraine. Otherwise, the new drugs have been developed first for other purposes, like anticonvulsants, antihypertensives and antidepressants used for migraine prophylaxis. For acute attacks, a new way to administer a traditional drug like dihydroergotamine is under way, and documentation of efficacy in migraine has been gained for some commonly used painkillers and anti-inflammatory drugs, and for some herbal extracts. Based on insights into the basic pathophysiological mechanisms of the disorder, some drugs have been developed which seem promising in early phase II studies (NOS inhibitors and 5HT1F-receptor agonists). In the future, development and enhancements of existing medicines must be accompanied by increased efforts to develop truly new migraine drugs based on knowledge of the pathophysiology if one wishes to reduce substantially the great burden migraine poses on patients and society.