STOP 101: A Phase 1, Randomized, Open-Label, Comparative Bioavailability Study of INP104, Dihydroergotamine Mesylate (DHE) Administered Intranasally by a I123 Precision Olfactory Delivery (POD® ) Device, in Healthy Adult Subjects

Intranasal Delivery of Medications for the Treatment of Neurologic Conditions: A Pharmacology Update

ABSTRACT

INTRODUCTION: Nurses have a central role in educating patients and families about treatment options and how to integrate them into action plans for neurologic conditions. In recent years, a growing number of intranasal formulations have become available as rescue therapy for neurologic conditions or symptoms including migraine, opioid overdose, and seizures. Rescue therapies do not replace maintenance medications or emergency care but are designed to enable rapid treatment of urgent or disabling conditions in community settings. Yet, discussion of rescue therapies for neurologic conditions remains limited in nursing literature. CONTENT: Intranasal formulations are specifically formulated for delivery and absorption in the nose and have several characteristics that are well suited as rescue therapies for neurologic conditions. Intranasal formulations include triptans for migraine, naloxone and nalmefene for opioid overdose, and benzodiazepines for seizure clusters in patients with epilepsy. Therapeutic attributes discussed here include ease of use in community settings by nonmedical professionals, relatively rapid onset of action, and favorable safety profile and patient experience. This information is critical for nurses to make informed decisions about rescue therapy options, incorporate these into plans of care, and educate patients, care partners, and other healthcare providers. CONCLUSION: Rescue therapies are increasingly important in the care of people with neurologic conditions. Various formulations are available and continue to evolve, offering easy and quick ways for nurses, patients, and nonmedical care partners to administer critical rescue medications. For nurses overseeing medication management, the attributes of intranasal rescue therapies should be considered in the context of providing patients with the right care at the right time.

Dihydroergotamine mesylate nasal spray: an acute treatment option for migraine in adults

INTRODUCTION

Although the landscape of migraine symptomatic treatment has been enriched by novel effective drugs, it is mandatory to critically reappraise older molecules to ascertain whether they could still represent reliable alternatives in specific endophenotypes of patients or migraine attacks. Among these, dihydroergotamine (DHE) nasal spray has been shown to be effective and is characterized by greater tolerability and manageability than the parenteral DHE formulation.

AREAS COVERED

In this narrative review, the authors describe the pharmacodynamic and pharmacokinetic properties of DHE nasal spray and explore the results of the trials which explored its efficacy, safety and tolerability as migraine symptomatic treatment. They also discuss the limitations of the classically used device and the attempts that several companies are carrying out to generate devices warranting a more reproducible drug absorption.

EXPERT OPINION

DHE nasal spray could be considered as rescue treatment in patients who have failed other symptomatic therapeutic strategies. Nevertheless, in the perspective of tailored therapy, the intranasal route of administration and the consequent rapid onset of action may represent benefits putatively making DHE a treatment of choice for challenging migraine attacks such as those with nocturnal onset or quickly reaching the climax of both headache and neurovegetative associated symptoms.

Safety, tolerability, and pharmacokinetics of a single orally inhaled dose of PUR3100, a dry powder formulation of dihydroergotamine versus intravenous dihydroergotamine: A Phase 1 randomized, double-blind study in healthy adults

BACKGROUND

Intravenous dihydroergotamine (DHE) has well-established efficacy for the acute treatment of migraine, but its use is limited by the need for in-hospital administration and the nausea/vomiting associated with a high maximum plasma concentration (Cmax). Inhalation is an alternative to intravenous dosing. The surface area of the lung allows for rapid absorption of a self-administered dose.

OBJECTIVE

This study evaluated the safety, tolerability, and systemic pharmacokinetics (PK) of a dry powder formulation (PUR3100) DHE when delivered via inhalation compared to intravenous delivery.

METHODS

In this double-blind, double-dummy Phase 1 study, healthy volunteers (N = 26) were randomized (1:1:1:1) to one of four groups: orally inhaled placebo plus intravenous DHE 1.0 mg or orally inhaled PUR3100 (0.5, 1.0, or 1.5 mg) plus intravenous placebo. Blood samples were drawn pre-dose and at time points post-dose over 48 h. Standard PK and safety parameters were assessed and values for Cmax and area under plasma concentration time curve (AUC) were used to assess comparative exposures of PUR3100 versus intravenous DHE.

RESULTS

All doses of PUR3100 were associated with a lower incidence of nausea (21% vs. 86%), vomiting (0% vs. 29%), and headache (16% vs. 57%) compared to intravenous DHE. The PK profile of PUR3100 versus intravenous DHE was characterized by a similar mean time to Cmax (5 vs. 5.5 min), with reduced AUC0-2h (1120-4320 vs. 6340), and a lower Cmax (3620-14,400 vs. 45,000). Compared to intravenous DHE 1.0 mg, the highest nominal PUR3100 dose (1.5 mg), which delivers a fine-particle dose of approximately 0.9 mg to the lungs, had a geometric mean ratio percentage (90% confidence interval [CI]) for Cmax of 32% [17.2, 59.6] and AUC0-inf of 93% (62.9, 138.5), the latter of which was not significantly different.

CONCLUSIONS

Inhaled PUR3100 is associated with rapid systemic PK within the therapeutic window and an improved safety profile relative to intravenous DHE.

Cardiovascular safety of dihydroergotamine mesylate delivered by precision olfactory delivery (INP104) for the acute treatment of migraine

OBJECTIVE

To report the cardiovascular (CV) safety of dihydroergotamine mesylate (DHE) administered by precision olfactory delivery (INP104) from two clinical trials.

BACKGROUND

Although the absolute risk is low, migraine is associated with an increased risk of CV events. DHE is a highly effective acute treatment for migraine, but due to its theoretical risk of promoting arterial vasoconstriction, DHE is contraindicated in patients with CV disease or an unfavorable risk factor profile. The INP104 is a novel drug-device combination product approved for acute treatment of migraine that delivers DHE to the upper nasal space using precision olfactory delivery (POD®).

METHODS

The STOP 101 was a Phase 1 open-label study that assessed the safety, tolerability, and bioavailability of INP104 1.45 mg, intravenous DHE 1.0 mg, and MIGRANAL (nasal DHE) 2.0 mg in healthy participants. The STOP 301 was a pivotal Phase 3, open-label study that assessed the safety, tolerability, and exploratory efficacy of INP104 1.45 mg over 24 and 52 weeks in patients with migraine. In both studies, active or a history of CV disease, as well as significant CV risk factors, were exclusion criteria.

RESULTS

In STOP 101, 36 participants received one or more doses of investigational product. Treatment with intravenous DHE, but not INP104 or nasal DHE, resulted in clinically relevant changes from baseline in systolic blood pressure (BP; 11.4 mmHg, 95% confidence interval [CI] 7.9-15.0) and diastolic BP (13.3 mmHg, 95% CI 9.4-17.1) at 5 min post-dose, persisting up to 30 min post-dose for systolic BP (6.3 mmHg; 95% CI 3.0-9.5) and diastolic BP (7.9 mmHg, 95% CI 3.9-11.9). None of the treatments produced any clinically meaningful electrocardiogram (ECG) changes. In STOP 301, 354 patients received one or more doses of INP104. Over 24 weeks, five patients (1.4%) experienced a non-serious, vascular treatment-emergent adverse event (TEAE). Minimal changes were observed for BP and ECG parameters over 24 or 52 weeks. Off-protocol concomitant use of triptans and other ergot derivatives did not result in any TEAEs.

CONCLUSION

In two separate studies, INP104 demonstrated a favorable CV safety profile when used in a study population without CV-related contraindications.

A randomized, open-label, 5-period crossover study evaluating the pharmacokinetics and safety of a single dose of intranasal dihydroergotamine (DHE) powder (STS101), intramuscular DHE mesylate, and liquid nasal spray DHE in healthy adults

OBJECTIVE

To compare the safety and pharmacokinetics (PK) of dihydroergotamine (DHE) after administration of intranasal DHE powder (STS101), liquid nasal spray (LNS) DHE mesylate, and intramuscular (IM) DHE mesylate injection in healthy participants.

BACKGROUND

DHE is an effective acute migraine treatment; however, self-administration difficulties have prevented its broader role in the management of migraine.

METHODS

This randomized, active-controlled, five-period crossover study was conducted over 5 weeks separated by 1-week washout periods. Three STS101 dosage strengths (5.2, 7.0, 8.6 mg), and one dose each of LNS DHE 2.0 mg, and IM DHE 1.0 mg, were administered to 36 healthy participants. Liquid chromatography, tandem mass spectrometry was used to determine DHE (including its 8'OH-DHE metabolite) plasma levels and to calculate PK parameters (Cmax , Tmax , AUC0-2h , AUC0-last , AUC0-inf , and t1/2 ). Safety was evaluated by monitoring adverse events (AEs), vital signs, electrocardiograms, nasal examinations, and laboratory parameters.

RESULTS

Thirty-six participants (mean age 36 years; 19% Hispanic Black and 81% Hispanic White) were enrolled. DHE plasma concentrations rose rapidly after STS101 5.2, 7.0, and 8.6 mg and IM DHE injection, with mean concentrations greater than 2000 pg/mL for all STS101 dose strengths at 20 min. All STS101 dose strengths showed approximately 3-fold higher Cmax , AUC0-2h , and AUC0-inf , than the LNS DHE. The mean AUC0-inf of STS101 7.0 and 8.6 mg were comparable to IM DHE (12,600 and 13,200 vs. 13,400 h × pg/mL). All STS101 dose strengths showed substantially lower variability (CV%) compared to LNS DHE for Cmax (35%-41% vs. 87%), and AUC0-inf (37%-46% vs. 65%). STS101 was well tolerated, and all treatment-emergent AEs were mild and transient.

CONCLUSION

STS101 showed rapid absorption and was well tolerated with mild and transient treatment-emergent AEs. Achieving effective DHE plasma concentrations within 10 min, STS101 displayed a favorable PK profile relative to the LNS with higher Cmax , AUC0-2h , and AUC0inf , and with greater response consistency. The AUC0-inf was comparable to IM DHE.

The Gut-brain Connection and Episodic Migraine: an Update

PURPOSE OF REVIEW

Historical evidence suggests a shared underlying etiology for migraine and gastrointestinal (GI) disorders that involves the gut-brain axis. Here we provide narrative review of recent literature on the gut-brain connection and migraine to emphasize the importance of tailoring treatment plans for patients with episodic migraine who experience GI comorbidities and symptoms.

RECENT FINDINGS

Recent population-based studies report the prevalence of migraine and GI disorders as comorbidities as well as overlapping symptomology. American Headache Society (AHS) guidelines have integrated GI symptoms as part of migraine diagnostic criteria and recommend nonoral therapies for patients with GI symptoms or conditions. Nasal delivery is a recommended nonoral alternative; however, it is important to understand potential adverse events that may cause or worsen GI symptoms in some patients due to the site of drug deposition within the nasal cavity with some nasal therapies. Lastly, clinical perspectives emphasize the importance of identifying GI symptoms and comorbidities in patients with episodic migraine to best individualize migraine management. Support for an association between the gut-brain axis and migraine continues to prevail in recent literature; however, the relationship remains complex and not well elucidated. The presence of GI comorbidities and symptoms must be carefully considered when making treatment decisions for patients with episodic migraine.

The Pharmacokinetics of Drugs Delivered to the Upper Nasal Space

Pharmacokinetics (PK) includes how a drug is absorbed, distributed, metabolized and eliminated. The compartment providing this information is usually the plasma. This is as close to the tissue of interest that we can get, although biopsies may be obtained to give "tissue levels" of drugs. Ultimately, the goal of PK is to understand how long the drug is actually engaged with the target in the tissue of interest after a dose has been administered. Most drugs at some point in their development will have been administered intravenously (IV), which acts as the standard for 100% bioavailability. By comparing various routes of administration to IV, the percentage of drug delivered to the plasma, on a dose-normalized basis, can be calculated and is referred to as the "absolute bioavailability". As pharmacology has advanced and more drugs have become available, many older products have been reformulated to be given by routes other than those originally intended (often oral). As the drawbacks of oral (or IV) administration have become better appreciated, non-oral, non-IV formulations and methods of administration have become more popular. Nasal administration is one route that has historically been overlooked as an alternative to oral administration-particularly for products needing rapid and non-invasive access to the target tissue-mostly via the blood stream. But attention is now focused on nasal administration for direct access to the brain, as that has the potential to bypass the blood-brain-barrier (BBB), which not even IV administration can always achieve. Assessing PK for these drugs targeting the brain may require serial sampling of the cerebrospinal fluid (CSF), making PK assessments of CNS drugs more invasive and complex, but still possible in future product development. However, we are now seeing more drugs reformulated for nasal delivery to gain faster systemic levels than oral administration (especially in patients with known or suspected gastrointestinal dysmotility), while avoiding the use of needles. For example, in recent years several different formulations and delivery methods for an old drug, dihydroergotamine (DHE), have been developed and these show very different characteristics, suggesting that delivery to different parts of the nose may have very different PK profiles. This review summarizes the systemic PK of different nasal DHE options that have been, or are being, developed and suggests that delivery of drugs to the upper nasal space (UNS) may represent an optimal target. Further research is required to ascertain if this route could also be utilized for direct administration to the CNS (as an attractive alternative to intrathecal delivery) via the olfactory or trigeminal nerves-but already preclinical data (and some human data) suggest this is entirely possible.

The Upper Nasal Space: Option for Systemic Drug Delivery, Mucosal Vaccines and "Nose-to-Brain"

Sino-nasal disease is appropriately treated with topical treatment, where the nasal mucosa acts as a barrier to systemic absorption. Non-invasive nasal delivery of drugs has produced some small molecule products with good bioavailability. With the recent COVID pandemic and the need for nasal mucosal immunity becoming more appreciated, more interest has become focused on the nasal cavity for vaccine delivery. In parallel, it has been recognized that drug delivery to different parts of the nose can have different results and for "nose-to-brain" delivery, deposition on the olfactory epithelium of the upper nasal space is desirable. Here the non-motile cilia and reduced mucociliary clearance lead to longer residence time that permits enhanced absorption, either into the systemic circulation or directly into the CNS. Many of the developments in nasal delivery have been to add bioadhesives and absorption/permeation enhancers, creating more complicated formulations and development pathways, but other projects have shown that the delivery device itself may allow more differential targeting of the upper nasal space without these additions and that could allow faster and more efficient programs to bring a wider range of drugs-and vaccines-to market.

Delivery of Dihydroergotamine Mesylate to the Upper Nasal Space for the Acute Treatment of Migraine: Technology in Action

Oral tablets account for the majority of medications used to acutely treat migraine, but relief can be limited by their rates of dissolution and absorption. The nose is an attractive alternative route of drug delivery since it provides patient convenience of at-home use, gastrointestinal (GI) avoidance, and rapid absorption of drugs into systemic circulation because of its large surface area. However, the site of drug deposition within the nasal cavity should be considered since it can influence drug absorption. Traditional nasal devices have been shown to target drug delivery to the lower nasal space where epithelium is not best-suited for drug absorption and where there is an increased likelihood of drug clearance due to nasal drip, swallowing, or mucociliary clearance, potentially resulting in variable absorption and suboptimal efficacy. Alternatively, the upper nasal space (UNS) offers a permeable, richly vascularized epithelium with a decreased likelihood of drug loss or clearance due to the anatomy of this area. Traditional nasal pumps deposit <5% of active drug into the UNS because of the nasal cavity's complex architecture. A new technology, Precision Olfactory Delivery (POD^®), is a handheld, manually actuated, propellant-powered, administration device that delivers drug specifically to the UNS. A dihydroergotamine (DHE) mesylate product, INP104, utilizes POD technology to deliver drug to the UNS for the acute treatment of migraine. Results from clinical studies of INP104 demonstrate a favorable pharmacokinetic profile, consistent and predictable dosing, rapid systemic levels known to be effective (similar to other DHE mesylate clinical programs), safety and tolerability on the upper nasal mucosa, and high patient acceptance. POD technology may have the potential to overcome the limitations of traditional nasal delivery systems, while utilizing the nasal delivery benefits of GI tract avoidance, rapid onset, patient convenience, and ease of use.

Acute Care and Treatment of Migraine

OBJECTIVE

Migraine is a chronic neurological disease involving the brain and its vasculature, typically characterized by recurrent attacks of moderate or severe throbbing headache, accompanied by sensitivity to light and sound, and associated with nausea, vomiting, and inability to move due to worsening of pain. About 30% of migraineurs have some type of aura, most often visual. Migraine attacks, if untreated or suboptimally treated, usually result in significant disability, requiring bed rest and resulting in poor quality of life. Increased frequency of attacks and overuse of acute care medication are significant risks for chronification, resulting in the transformation of episodic migraine into chronic migraine. We aim to review most acute care treatments for migraine.

METHODS

Current treatment options for migraine attacks were reviewed from the selected literature and combined with our clinical experience.

RESULTS

Current acute treatment options for migraine attacks include over-the-counter analgesics, at times combined with caffeine, nonsteroidal anti-inflammatory medications, opioids, and migraine-specific medications such as triptans and ergots. In the near future, we will probably have 3 gepants (small-molecule calcitonin gene-related peptide [CGRP] receptor antagonists). The first one was just approved in the United States. A ditan acting as a stimulator of 5-HT1F receptors, was also just approved by the FDA. Stimulation of the trigeminal, vagal, occipital, and even upper arm peripheral nerves through electrical nerve stimulation devices and magnetic stimulation devices are available as alternative, nondrug treatment options. Several devices have already been FDA-allowed for treatment in the United States and/or approved elsewhere, and others will follow soon. Behavioral medicine techniques such as biofeedback training and mindfulness have been available for some time and are often helpful.

CONCLUSION

A wide variety of acute care options to treat migraine are available, and others will soon be and will herein be described in further detail. Some medications have been approved by regulatory authorities in countries other than the United States, and some devices have been given a CE Mark in Europe.

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.

Nasal Delivery of Acute Medications for Migraine: The Upper Versus Lower Nasal Space

The acute treatment of migraine requires effective drugs that are well tolerated and provide rapid and consistent pain relief. Oral tablets are the most commonly used acute treatment for migraine; however, their effectiveness is limited by the rate of gastrointestinal (GI) tract absorption and first-pass hepatic metabolism, and they may not be ideal for patients experiencing GI motility issues. Nasal delivery is an attractive alternative route as it may circumvent GI tract absorption, avoid first-pass metabolism in the liver, and potentially reduce the frequency of GI adverse events. The large surface area and high vascularity within the nose may permit rapid absorption of therapeutics into the systemic circulation, allowing for rapid onset of action. However, the site of drug deposition (upper versus lower nasal cavity) may influence drug pharmacokinetics. Most approved nasal migraine therapies target the lower nasal space where the epithelium is less permeable, and they may be quickly cleared away due to increased ciliary function or dripping from the nose or swallowing, resulting in variable absorption and limited bioavailability. Together with its abundant vascularization, relative mucosal thickness stability, and low clearance rates, the upper nasal space harnesses the benefits of nasal delivery to potentially maximize drug efficacy.

A Phase 1, Randomized, Open-Label, Safety, Tolerability, and Comparative Bioavailability Study of Intranasal Dihydroergotamine Powder (STS101), Intramuscular Dihydroergotamine Mesylate, and Intranasal DHE Mesylate Spray in Healthy Adult Subjects

Objective

To investigate and compare the safety and the pharmacokinetics of dihydroergotamine (DHE) after administration of intranasal DHE powder (STS101), intranasal DHE spray (Migranal^®), and intramuscular (IM) DHE injection in healthy subjects.

Methods

This was a 2‐part, active‐controlled, 3‐period crossover study over 3 weeks, separated by 1‐week washout periods. In part 1, 3 ascending dosage strengths of STS101 (1.3, 2.6, and 5.2 mg) were administered to 15 healthy subjects with no history of migraine. In part 2, 27 healthy subjects were administered 1 dose each of STS101 5.2 mg, Migranal DHE Mesylate Liquid Nasal Spray 2.0 mg, and IM DHE Mesylate 1.0 mg in a randomized order. Liquid chromatography, tandem mass spectrometry was used to determine plasma levels of DHE and its major metabolite, 8′OH‐DHE. Pharmacokinetic parameters (C_max, T_max, AUC_0‐2 h, AUC_0‐48 h, AUC_0‐inf, and t_1/2) for DHE and metabolite were calculated. Geometric means and 90% confidence intervals of log‐transformed data were calculated and the ratio of means compared. Safety was evaluated by monitoring adverse events, vital signs, electrocardiograms, subjective and objective assessments of nasal signs and symptoms, and changes in laboratory parameters. The study is registered as NCT03874832.

Results

Forty‐three subjects were enrolled and received study medication. Forty completed all study activities, 14 in part 1 and 26 in part 2. In part 1, DHE plasma levels showed a dose‐dependent increase, with STS101 5.2 mg reaching a mean C_max of 1870 pg/mL with a T_max of 23 minutes. In part 2, STS101 5.2 mg showed rapid absorption, achieving mean DHE plasma concentrations of 1230 and 1850 pg/mL at 10 and 15 minutes after administration, respectively. In comparison to Migranal, STS101 5.2 mg showed approximately 2‐fold higher C_max (2175 vs 961 pg/mL), AUC_0‐2 h (2979 vs 1316 h × pg/mL), and AUC_0‐inf (12,030 vs 6498 h × pg/mL), respectively. The mean AUC_0‐inf of STS101 5.2 mg was comparable to IM DHE (12,030 vs 13,650 h × pg/mL). STS101 5.2 mg showed substantially lower variability compared to Migranal for C_max (41% vs 76%), AUC_0‐2 h (39% vs 75%), and AUC_0‐inf (39% vs 55%). The incidence of treatment emergent AEs (TEAEs), all mild and transient, reported in parts 1 and 2 combined was 9/15 (60%), 5/15 (33%), and 16/41 (39%) of the subjects after 1.3, 2.6, and 5.2 mg STS101, respectively, and 4/26 (15%) and 5/27 (19%) of the subjects after IM DHE and Migranal, respectively.

Conclusion

STS101 showed rapid absorption, achieving effective DHE plasma concentrations within 10 minutes. It achieved substantially higher C_max, AUC_0‐2 h and AUC_0‐inf, compared to Migranal suggesting potentially better efficacy than Migranal. Its variability was better than Migranal, thus offering improved consistency of response. AUC_0‐inf was comparable to IM DHE, suggesting prolonged action and low recurrence. Additionally, the C_max was sufficiently low to avoid any significant nausea reported with IV DHE. Thus, STS101 is an easy to administer, non‐injected, acute treatment for migraine, with a favorable tolerability profile and is expected to provide rapid and consistent freedom from pain and associated migraine symptoms without recurrence.

The Upper Nasal Space—A Novel Delivery Route Ideal for Central Nervous System Drugs

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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.

Intranasal delivery of low-dose insulin ameliorates motor dysfunction and dopaminergic cell death in a 6-OHDA rat model of Parkinson's Disease

Emerging evidence continues to demonstrate that disrupted insulin signaling and altered energy metabolism may play a key role underpinning pathology in neurodegenerative conditions. Intranasally administered insulin has already shown promise as a memory-enhancing therapy in patients with Alzheimer's and animal models of the disease. Intranasal drug delivery allows for direct targeting of insulin to the brain, bypassing the blood brain barrier and minimizing systemic adverse effects. In this study, we sought to expand upon previous results that show intranasal insulin may also have promise as a Parkinson's therapy. We treated 6-OHDA parkinsonian rats with a low dose (3 IU/day) of insulin and assessed apomorphine induced rotational turns, motor deficits via a horizontal ladder test, and dopaminergic cell survival via stereological counting. We found that insulin therapy substantially reduced motor dysfunction and dopaminergic cell death induced by unilateral injection of 6-OHDA. These results confirm insulin's efficacy within this model, and do so over a longer period after model induction which more closely resembles Parkinson's disease. This study also employed a lower dose than previous studies and utilizes a delivery device, which could lead to an easier transition into human clinical trials as a therapeutic for Parkinson's disease.