- Male or female of any race, between the ages of 18 and 75 years inclusive
- Female subjects must be of non-childbearing potential and have a negative pregnancy
test at Screening.
- Osteoarthritis of the knee of at least 6 months duration and meeting the American
College of Rheumatology Criteria. For radiographic criteria the Xray must have been
taken within the last 5 years. If none is available, one should be taken and the
diagnostic criteria confirmed prior to randomization.
- Willing and able to discontinue all current analgesic therapy, including OTC pain
medications and topical analgesics for OA pain, for period beginning with washout
phase (lasting 2 days or 5 half-lives of patient's current analgesic medication prior
to Day -6) and continuing for the entire duration of study. As an exception,
acetaminophen may be used for non-joint related pain at doses ≤1 g/day at the
discretion of a qualified member of the study team.
- If a subject has evidence or a history of clinically significant endocrine, pulmonary,
gastrointestinal, cardiovascular, hepatic, renal, psychiatric, or neurological
disease, the investigator must confirm that the disease is stable (at least 4 weeks)
and under control.
- QTc interval ≤450 msec and a PR interval ≤210 msec on Screening ECG.
- Pregnant or lactating females, and females of childbearing potential.
- Arthroscopy performed on index knee within 1 year of screening.
- Active depression as defined by or meeting The Hospital Anxiety and Depression Scale
(HADS) of >10.
- Unwillingness to refrain from consumption of grapefruit or grapefruit juice from 7
days prior to the first dose of study medication until completion of the study.
- First degree or higher AV block, defined as PR interval >210 msecs, bundle branch
block, fascicular block or intraventricular conduction delay or clinically relevant
abnormality on screening ECG.
- Active malignancy of any type or history of a malignancy within 10 years (with the
exception of subjects with a history of treated basal cell carcinoma).
- Symptomatic OA of the hip ipsilateral to index knee which the patient considers more
painful than the knee.
- Use of prohibited medications as listed below, in the absence of appropriate washout
period. The following analgesic agents must be discontinued within 48 hours or 5 half
lives of the analgesic being washed out prior to the baseline period (Day -6 to Day
- NSAIDs and selective COX-2 inhibitors;
- Acetaminophen ( as an exception acetaminophen may be used for non-joint related
pain at doses ?1g/day);
- Oral or I/M corticosteroids within 4 weeks prior to screening. I/A steroids
within 12 weeks prior to baseline in study joint or any other joints within 4
weeks prior to baseline, or I/A hyaluronic acid within 24 weeks prior to
- Use of concomitant medications that are CYP3A inhibitors or CYP3A inducers, or
that are P-glycoprotein substrates within 48 hours or 5 half lives prior to