Conditions: Osteoarthritis of the Knee
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 171
Healthy volunteers: no

Brief summary:
The purpose of this study is to assess the efficacy of a single dose level of gefapixant (AF-219/MK-7264) in subjects with moderate to severe pain associated with osteoarthritis (OA) of the knee compared with placebo after 4 weeks of treatment.

The study will also assess the safety and tolerability, changes in physical function, stiffness, treatment response and health outcomes.

Detailed description:
Subjects who satisfy entry criteria at Screening will enter the Washout Phase, discontinuing their current nonsteroidal anti-inflammatory drug (NSAID) therapy.

Up to 220 subjects who fulfill flare (and other entry) criteria will be randomized to gefapixant or placebo.

Subjects will complete Treatment Visits 1, 2, 3, and 4 weeks after starting study drug. At each Treatment Visit, subjects will undergo efficacy assessments and safety procedures. During the Washout and Treatment Phases subjects will complete the 'average pain' Numeric Pain Rating Scale (NPRS) and count of rescue medication used for the preceding 24 hours.

Subjects will return 2 weeks after their last Treatment Visit (for a Follow-Up Visit).

Arms:
arm 1: None arm 2: None

Interventions: intervention 1: Gefapixant intervention 2: Sugar Pill
Intervention descriptions: intervention 1: BID intervention 2: Placebo

Protocol document: