Intranasal DHE Meets Primary Objectives in Treatment of Acute Migraine

Stephen B. Shrewsbury, MD

Impel NeuroPharma announced that its new therapy, INP104 (dihydroergotamine; DHE), met its primary objectives with no new safety signals or concerning trends in nasal safety findings in the phase 3, open-label STOP-301 study (NCT03557333) in patients with acute migraine.

The Primary Safety Set (PSS), which included 185 patients, showed that 33.1% of patients who took an average of 2 or more doses of INP104 per the 28-day period during the 24-week treatment phase achieved pain freedom at 2 hours. Initial onset of pain relief began as early as 15 minutes for 16.3% of patients, and continued to improve over time.

Overall 74% and 90% of patients completed the 24- and 52-week phases of the study, respectively. Over the entire 52 weeks, there were no reported drug-related serious AEs. In the Full Safety Set (n = 354), 66.3% of patients achieved pain relief and 38% of patients achieved pain freedom at 2 hours following their first dose of INP104.

Sustained pain freedom was observed in the majority of patients, with 98.4% and 95% of patients reporting no recurrence of their migraine or use of rescue medications during thee 24- and 48-hour periods after using INP104 during Weeks 21—24.

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In the FSS, researchers found the majority of treatment-related adverse events (AEs) for the 24-week set were mild and transient in nature. More notably, the most frequently reported AEs (occurring at a rate ≥5%) during the 24-week period were nasal congestion (15.0%), nausea (6.8%), nasal discomfort (5.1%) and unpleasant taste (5.1%).

"We believe that these data add to the growing body of clinical evidence supporting the potential of INP104 to be a transformative new therapy for acute migraine,” Stephen B. Shrewsbury, MD, chief executive officer, Impel NeuroPharma, said in a statement. “In addition to the STOP 301 study demonstrating INP104's potential to be both safe and well-tolerated when delivered to the upper nasal space, the data showed unsurpassed and sustained patient-reported pain freedom and pain relief rates compared to the best usual care in our exploratory efficacy analyses.”

Withdrawal by subject (n = 25; 7.1%), AEs (n = 24; 6.8%), lack of efficacy (n = 21; 5.9%), lost to follow-up (n = 11; 3.1%), non-compliance/protocol violation (n = 5; 1.4%) and physician’s decision (n = 1; 0.3%) were all documented as reasons for treatment discontinuation.

INP104 is the first and only product designed to deliver a lower dose of DHE compared to FDA-approved and investigational products in development to the vascular-rich upper nasal space. The agent aims to optimize DHE for fast and lasting migraine relief, regardless of when in the migraine attack it is administered, without an injection.

"Despite historically being known as a highly effective treatment, use of DHE in the treatment of acute migraine has been limited due to dose-related side effects, inadequate or inconvenient routes of administration and high variability in dose delivered, making these data highly encouraging for clinicians who need an at-home option that also has the benefit of broad neurogenic activity,” Stewart J. Tepper, MD, professor of neurology, Geisel School of Medicine at Dartmouth, and director, Dartmouth Headache Center, Dartmouth-Hitchcock Medical Center, said in a statement.

Impel NeuroPharma concluded that further analysis of STOP-301 data is ongoing and will be submitted for future publication or presentation. The biopharmaceutical company plans to submit a new drug application (NDA) to the FDA for INP104 in the second half of 2020.

REFERENCE

Impel NeuroPharma announces primary objectives met in pivotal phase 3 registration study of INP104 for the treatment of acute migraine [news release]. Seattle, WA: Impel NeuroPharma; Published June 10, 2020. Accessed June 12, 2020. prnewswire.com/news-releases/impel-neuropharma-announces-primary-objectives-met-in-pivotal-phase-3-registration-study-of-inp104-for-the-treatment-of-acute-migraine-301073558.html