ByCOLLEEN CREAMER
For VerusMed
Eli Lilly and Co.’s Cymbalta (duloxetine hydrochloride) significantly decreases osteoarthritis pain of the knee as compared with placebo, results of a new study show.
Researchers assessed 231 patients with osteoarthritis pain of the knee who were randomized to receive Cymbalta 60 mg/day or placebo. The patients were stratified by whether or not they used nonsteroidal anti-inflammatory drugs on a regular basis. Patients with a diagnosis of major depressive disorder within the six-month period prior to trial initiation were excluded. At week seven, those in the Cymbalta group were re-randomized to receive either Cymbalta 60 mg/d or Cymbalta 120 mg/d. The two groups were combined for the overall analyses.
Cymbalta showed statistically significant improvements in pain associated with osteoarthritis of the knee according to the primary efficacy measure of weekly mean of the 24-hour average pain scores.
Specifically, 59 percent of the Cymbalta-treated patients experienced a 30 percent improvement in pain compared with 45 percent of the patients who received placebo. Forty-seven percent of the Cymbalta-treated patients experienced a 50 percent improvement in pain compared with 29 percent of the placebo-treated patients.
In addition, the patients in the Cymbalta group reported significant pain improvement as compared with placebo within the first week of treatment, an effect that lasted throughout the 13-week trial. Treatment with Cymbalta was associated with improvements in patient outcomes, as measured by the Patient Global Impressions of Improvement scale; physical functioning, as measured by the Western Ontario and McMaster Universities (WOMAC) physical functioning subscale; pain severity, as measured by the Brief Pain Inventory and WOMAC; and symptom severity, as measured by the Clinical Global Impressions of Severity scale.
The most common adverse events were nausea, fatigue, somnolence, dizziness, hypertension, constipation and decreased libido. A total of 22 (9.5 percent) patients discontinued participation in the trial due to adverse events–seven (5.8 percent) in the placebo group and 15 (13.5 percent) in the Cymbalta group.
Cymbalta is approved in the United States for the acute and maintenance treatment of major depressive disorder, the acute treatment of generalized anxiety disorder and the management of diabetic peripheral neuropathic pain all in patients aged 18 years or older. According to Lilly, Cymbalta is believed to potentiate the activity of serotonin and norepinephrine in the central nervous system, thereby possibly regulating the perception of pain; however, the drug’s mechanism of action is not fully known.
“These data are important because it’s the first time [Cymbalta] has been studied in a large, placebo-controlled trial in what’s classified as an inflammatory disease state,” said Dr. Amy Chappell, lead study author. “Although the exact mechanism of action is unknown, this study may provide important insights into the treatment of pain in the central nervous system.”
These results were presented in Paris at The European League Against Rheumatism’s 2008 Annual European Congress of Rheumatology. Lilly submitted a supplemental New Drug Application to the Food and Drug Administration in May seeking approval of Cymbalta in the management of chronic pain.
