Conditions: Asthma
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 20
Healthy volunteers: no

Brief summary:
This is a randomized, double-blind, double-dummy, placebo-controlled, three-way cross-over, single centre study in participants with asthma undergoing inhalation of methacholine and adenosine triphosphate (ATP) to assess the provocative concentration (PC20) response of two dose levels of gefapixant (AF-219) compared with placebo.

Detailed description:

Arms:
arm 1: Gefapixant 50 mg and placebo (for gefapixant 300 mg) twice daily for 3.5 days during Period 1, gefapixant 300 mg and placebo (for gefapixant 50 mg) twice daily for 3.5 days during Period 2, placebo to match gefapixant 50 mg and placebo to match gefapixant 300 mg twice daily for 3.5 days during Period 3. Each period is separated by at least a 7-day wash-out period. arm 2: Gefapixant 50 mg and placebo (for gefapixant 300 mg) twice daily for 3.5 days during Period 1, placebo to match gefapixant 50 mg and placebo to match gefapixant 300 mg twice daily for 3.5 days during Period 2, gefapixant 300 mg and placebo (for gefapixant 50 mg) twice daily for 3.5 days during Period 3. Each period is separated by at least a 7-day wash-out period. arm 3: Gefapixant 300 mg and placebo (for gefapixant 50 mg) twice daily for 3.5 days during Period 1, gefapixant 50 mg and placebo (for gefapixant 300 mg) twice daily for 3.5 days during Period 2, placebo to match gefapixant 50 mg and placebo to match gefapixant 300 mg twice daily for 3.5 days during Period 3. Each period is separated by at least a 7-day wash-out period. arm 4: Gefapixant 300 mg and placebo (for gefapixant 50 mg) twice daily for 3.5 days during Period 1, placebo to match gefapixant 50 mg and placebo to match gefapixant 300 mg twice daily for 3.5 days during Period 2, gefapixant 50 mg and placebo (for gefapixant 300 mg) twice daily for 3.5 days during Period 3. Each period is separated by at least a 7-day wash-out period. arm 5: Placebo to match gefapixant 50 mg and placebo to match gefapixant 300 mg twice daily for 3.5 days during Period 1, gefapixant 50 mg and placebo (for gefapixant 300 mg) twice daily for 3.5 days during Period 2, gefapixant 300 mg and placebo (for gefapixant 50 mg) twice daily for 3.5 days during Period 3. Each period is separated by at least a 7-day wash-out period. arm 6: Placebo to match gefapixant 50 mg and placebo to match gefapixant 300 mg twice daily for 3.5 days during Period 1, gefapixant 300 mg and placebo (for gefapixant 50 mg) twice daily for 3.5 days during Period 2, gefapixant 50 mg and placebo (for gefapixant 300 mg) twice daily for 3.5 days during Period 3. Each period is separated by at least a 7-day wash-out period.

Interventions: intervention 1: Gefapixant 50 mg intervention 2: Gefapixant 300 mg intervention 3: Placebo to mimic 50 mg tablets intervention 4: Placebo to mimic 300 mg tablets
Intervention descriptions: intervention 1: Gefapixant 50 mg tablet administered orally intervention 2: Gefapixant 300 mg tablet administered orally intervention 3: Sugar pill manufactured to mimic gefapixant 50 mg tablets intervention 4: Sugar pill manufactured to mimic gefapixant 300 mg tablets

Protocol document: