Calosyn Pharma, Inc.

This is a randomized, double-blind, placebo-controlled, multi-center study to evaluate the safety, tolerability, and efficacy of Intra-Articular (IA) verapamil in the treatment of joint pain in patients with knee osteoarthritis (OA). Subjects will discontinue all analgesic medications for the entire duration of the study, except for acetaminophen (taken on an as needed basis at no more than 2 g/day). At visit 2, subjects who meet all entry criteria will be randomized to receive a single injection of IA verapamil or IA placebo at a ratio of 1:1. Treatments will be given with fluoroscopy or ultrasound to confirm needle placement. Subjects will be monitored for blood pressure and heart rate (sitting and standing) for at least 1 hour post-injection. Subjects will be evaluated at weeks 1, 2, 3, 4, 6, 8, and 12 after treatment.