SSSA: Spontaneous Symptom Severity Assessment; mITT: modified intent-to-treat. p < 0.05: statistically significant difference between treatment groups; p < 0.10: viewed as a trend towards a significant difference between treatment groups. Note: p-values are from Wilcoxon rank sum tests comparing treatments. Results for Hour 0 on Days 3 and 4 and for Day 8 are treatment comparisons based on within-subject changes from Baseline (Day 1). Results for Hour 3 on Days 3 and 4 are treatment comparisons based on within-subject changes from Hour 0 of the same day.