Flexion Therapeutics of Woburn, Mass., has released results from the phase II proof-of-concept trial of its lead osteoarthritis drug candidate, FX005, which demonstrated significant pain relief over placebo at four weeks.

Top-line data from the double-blind, placebo-controlled study showed FX005, delivered intra-articularly to the knee, was well tolerated and resulted in prolonged improvement in joint pain and function throughout the 12-week duration of the study. This study demonstrates the first-ever clinical results demonstrating the efficacy of a p38 MAP kinase inhibitor in osteoarthritis patients. Flexion plans to present the complete data set and analyses at an upcoming medical conference.

"There is considerable unmet need for treatments for the pain and damage caused by osteoarthritis," said Timothy McAlindon, chair of rheumatology and professor of medicine at Tufts Medical Center. "In particular, physicians and patients need targeted treatments for osteoarthritis that are more effective and longer lasting. These results represent a significant advance in that direction, so we will eagerly monitor development of this new treatment." 

Flexion will be advancing FX005 to a phase IIb dose-ranging study, planned to initiate in the first half of 2013.