Positive results were announced from the phase 3 STOP-301 study evaluating INP104 (intranasal dihydroergotamine mesylate; Impel NeuroPharma) for the treatment of acute migraine in adults.

INP104 is designed to deliver a lower dose (1.45mg) of dihydroergotamine mesylate (DHE) to the upper nasal space using the Company’s proprietary POD® technology. The Company believes this formulation could potentially reduce treatment-emergent adverse events. An intranasal formulation of DHE that delivers a higher dose is currently approved by the Food and Drug Administration under the brand name Migranal (4mg/mL). 

The multicenter, open-label study included 354 patients who had a documented diagnosis of migraine with or without aura, with at least 2 attacks per month for the previous 6 months. Patients who received at least 1 dose of INP104 comprised the Full Safety Set (n=354), and patients who took ≥2 doses of INP104 per 28-day period during the 24-week treatment period comprised the Primary Safety Set (n=185). The primary safety end points included serious and non-serious treatment-emergent adverse events as well as changes in nasal mucosa and olfactory function. 

Results showed the study met its primary end points with no new safety signals. Most of the treatment emergent adverse events in the Full Safety Set were mild and transient in nature with no serious adverse events reported. The most common adverse events (≥5%) were nasal congestion (15.0%), nausea (6.8%), nasal discomfort (5.1%) and unpleasant taste (5.1%).

Additionally, exploratory efficacy data in the Full Safety Set showed that 66.3% of patients achieved pain relief and 38% achieved pain freedom at 2 hours after the first dose of INP104; 33.1% of patients in the Primary Safety Set achieved pain freedom at 2 hours. Moreover, 16.3% of patients reported initial pain relief as early as 15 minutes with continued improvement over time. A majority of patients also reported sustained pain freedom with no recurrence of their migraine or use of rescue medications after using INP104 for 24- (98.4%) and 48-hour (95%) periods during weeks 21-24.

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“Interestingly, an increased recognition of the link between migraine and gastrointestinal issues may be why nearly 60% and 90% of patients with migraine experience vomiting and nausea, respectively, during an attack which presents limitations for the use of oral therapies,” said Stewart J. Tepper, MD, Professor of Neurology at the Geisel School of Medicine at Dartmouth and Director of the Dartmouth Headache Center in the Department of Neurology of Dartmouth-Hitchcock Medical Center. “If approved, INP104 has the potential to offer patients a non-oral alternative with an all-in-one approach to treating the whole migraine due to DHE’s broad receptor binding profile.” 

Further analysis is ongoing and will be submitted for future publication or presentation. The Company plans to submit a New Drug Application (NDA) for INP104 in the second half of 2020.

For more information visit impelnp.com.