Conditions: Refractory Chronic Cough
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 59
Healthy volunteers: no

Brief summary:
A randomized, double-blind, placebo-controlled, crossover, dose escalation study to assess the efficacy and tolerability of gefapixant (AF-219; MK-7264) in participants with refractory chronic cough.

Detailed description:

Arms:
arm 1: 50, 100, 150, and 200 mg gefapixant twice daily (BID) for 4 days each in Period 1 and placebo BID for 16 days in Period 2. For Cohort 1, there was a 3 to 7 day washout period between treatment periods. arm 2: Placebo BID for 16 days in Period 1 and gefapixant 50, 100, 150, and 200 mg BID for 4 days each in Period 2. For Cohort 1, there was a 3 to 7 day washout period between treatment periods. arm 3: Gefapixant 7.5, 15, 30, and 50 mg BID for 4 days each in Period 1 and placebo BID for 16 days in Period 2. For Cohort 2, there was a 14 to 21 day washout period between treatment periods. arm 4: Placebo BID for 16 days in Period 1 and gefapixant 7.5, 15, 30, and 50 mg BID for 4 days each in Period 2. For Cohort 2, there was a 14 to 21 day washout period between treatment periods.

Interventions: intervention 1: Gefapixant intervention 2: Placebo (for gefapixant)
Intervention descriptions: intervention 1: Gefapixant 7.5 and 50mg tablets administered orally intervention 2: Placebo to gefapixant 7.5 and 50mg tablets administered orally

Protocol document: