INDIANAPOLIS, Indiana—Lilly looks set to pursue approval for its antidepressant Cymbalta® (duloxetine) for osteoarthritis (OA) knee pain and other types of chronic pain. Initial knee OA data reported at the 2008 EULAR conference were expanded in a report just presented at the American Academy of Pain Medicine (AAPM) meeting in Honolulu, Hawaii.

In that 13-week, randomized, placebo-controlled study, researchers observed both pain and function improvements in patients randomized to Cymbalta 60-120 mg, taken once daily. The treatment reduced pain severity significantly, compared with placebo, in patients with osteoarthritis pain of the knee.

In the study, 65 percent of duloxetine-treated patients experienced a clinically significant (at least 30 percent) improvement in pain, compared with 44 percent of placebo-treated patients.

The duloxetine-treated patients also showed improved physical function, compared with placebo-treated patients, as measured by the Western Ontario and McMaster Osteoarthritis Index (WOMAC), but they did not show statistically significant improvements on the WOMAC pain and stiffness subscales.

The most common adverse events were nausea, constipation and excessive sweating (hyperhidrosis).  A total of 31 patients in the study discontinued due to adverse events—seven in the placebo-treated group and 24 in the duloxetine-treated group.

Lilly had withdrawn a previously submitted supplemental new drug approval (s-NDA) application for chronic pain for Cymbalta, but a company spokesperson tells Musculoskeletal Report that the application will be resubmitted in the first half of 2009 and will include the OA knee pain data.