Table 2.
Exploratory Efficacy End Point Results
| End Point | All Subjects | eCH Cohort | cCH Cohort | |||
|---|---|---|---|---|---|---|
| nVNS | Sham | nVNS | Sham | nVNS | Sham | |
| Subjects who were responders at 15 minutes for ≥50% of their treated attacks in the double‐blind phase (%) † , ‡ | 26.7 | 20.6 | 34.2 | 14.9 | 13.6 | 30.8 |
| 95% CI | 16.1, 39.7 | 12.0, 31.6 | 19.6, 51.4 | 6.2, 28.3 | 2.9, 34.9 | 14.3, 51.8 |
| P value | .41 | .04 | .19 | |||
| Subjects who were pain‐free at 15 minutes for ≥50% of their treated attacks in the double‐blind phase (%) † , ‡ | 11.7 | 6.9 | 15.8 | 2.1 | 4.6 | 15.4 |
| 95% CI | 4.8, 22.6 | 2.3, 15.3 | 6.0, 31.3 | 0.1, 11.3 | 0.1, 22.8 | 4.4, 34.9 |
| P value | .33 | .04 | .36 | |||
| Duration of first CH attack in the double‐blind phase (min), § , ¶ mean ± SD | 50.6 ± 38.3 | 59.9 ± 47.5 | 48.4 ± 35.4 | 61.2 ± 49.5 | 54.5 ± 43.8 | 57.6 ± 44.8 |
| 95% CI | 40.0, 61.1 | 48.0, 71.7 | 36.0, 60.7 | 45.4, 77.1 | 33.4, 75.6 | 38.7, 76.5 |
| P value | .25 | .21 | .82 | |||
| Change in duration of attacks from baseline to the first attack in the double‐blind phase (min), §,††,‡‡ mean ± SD | −9.5 ± 51.8 | 12.8 ± 45.5 | −14.4 ± 59.5 | 16.3 ± 51.5 | 1.0 ± 28.6 | 5.4 ± 29.2 |
| 95% CI | −25.8, 6.9 | 0.2, 25.3 | −37.4, 8.7 | −1.1, 33.7 | −16.3, 18.3 | −9.7, 20.4 |
| P value | .03 | .03 | .69 | |||
| Rescue medication use in the first hour after treatment initiation (first attack) in the double‐blind phase (%) † | 38.3 | 50.7 | 42.1 | 48.9 | 31.8 | 53.9 |
| 95% CI | 26.1, 51.8 | 38.7, 62.6 | 26.3, 59.2 | 34.1, 63.9 | 13.9, 54.9 | 33.4, 73.4 |
| P value | .15 | .53 | .13 | |||
cCH = chronic cluster headache; CH = cluster headache; CI = confidence interval; eCH = episodic cluster headache; ITT = intent‐to‐treat; nVNS = non‐invasive vagus nerve stimulation; SD = standard deviation.
†ITT population; all subjects: nVNS, n = 60; sham, n = 73; eCH cohort: nVNS, n = 38; sham, n = 47; cCH cohort: nVNS, n = 22; sham, n = 26.
‡No rescue medication use through 60 minutes after treatment initiation; P values are from Fisher's exact test (if ≥1 cell had an expected frequency of ≤5) or the chi‐square test.
§Attacks with duration >180 minutes were excluded according to International Classification of Headache Disorders criteria; P values are from the t test.
¶Observed cases; all subjects: nVNS, n = 53; sham, n = 64; eCH cohort: nVNS, n = 34; sham, n = 40; cCH cohort: nVNS, n = 19; sham, n = 24.
††Change from the last attack before randomization (based on subject recollection) to the first attack in the double‐blind phase (based on objective recording).
‡‡Observed cases; all subjects: nVNS, n = 41; sham, n = 53; eCH cohort: nVNS, n = 28; sham, n = 36; cCH cohort: nVNS, n = 13; sham, n = 17.