In a new study, Cymbalta (duloxetine HCl) 60-120 mg, taken once daily, reduced pain severity significantly, compared with placebo, in patients with osteoarthritis pain of the knee. Data from the 13-week randomized, double-blind, placebo-controlled clinical trial(1) were presented at the annual meeting of the American Academy of Pain Medicine (AAPM) in Honolulu, Hawaii.
Duloxetine-treated patients showed greater reductions from baseline on the primary endpoint, the 24-hour average pain score on the Brief Pain Inventory (BPI), compared with placebo-treated patients. 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). In this study, patients on duloxetine did not show statistically significant improvements on the WOMAC pain and stiffness subscales compared with placebo.
“The disabling nature of osteoarthritis pain can greatly impact a person’s life,” said Vladimir Skljarevski, M.D., a study author and medical fellow at Eli Lilly and Company. “As our population ages, osteoarthritis of the knee is likely to become an increasing problem.”
The most common adverse events in the study (occurred at a rate of greater than or equal to 5 percent and at least twice the rate of placebo) included nausea, constipation and excessive sweating (hyperhidrosis). Adverse events were similar to those seen in previous duloxetine studies.
Additional Study Highlights
– Compared with patients receiving placebo, patients receiving duloxetine experienced additional improvements associated with osteoarthritis pain of the knee, including:
– Decreased interference from pain in general activity and normal work, as measured by the BPI Pain Interference (BPI-I) scales.
– Duloxetine-treated patients did not show statistically significant improvements compared with placebo-treated patients according to BPI-I measures of mood, walking ability, relations with other people, sleep, enjoyment of life and average interference.
– Weekly mean of the 24-hour average pain severity and worst pain severity.
– PGI-Improvement (PGI-I).
– Duloxetine-treated patients showed statistically significant improvements compared with placebo as measured by PGI-I at each office visit, but not at study endpoint.
– 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.
It is estimated that 27 million adults in the United States have osteoarthritis and the prevalence increases with age.(2) Osteoarthritis of the knee is a common subtype of this disorder, impacting the lives of approximately 10 million Americans.(2) In addition to pain, other symptoms of osteoarthritis include aching, stiffness and limited range of motion of the joint.(3) Duloxetine is being studied to manage the pain associated with this disorder.
In this 13-week double-blind trial, patients were at least 40 years of age without a current diagnosis of major depressive disorder; with no confounding painful conditions or diagnosis of inflammatory arthritis or autoimmune disorders; and with no invasive therapy of the knee in the past three months, knee arthroscopy within the past year or joint replacement of the index knee at anytime. Patients were randomized to duloxetine (n=128) or placebo (n=128) and stratified by whether or not they used nonsteroidal anti-inflammatory drugs. At week seven, patients who showed suboptimal response to the 60 mg (33 patients) dose had their dose increased to 120 mg. The primary efficacy endpoint of the study was the Brief Pain Inventory (BPI) 24-hour average pain rating, which was analyzed using a mixed-model repeated measures (MMRM) approach. Secondary outcomes included the BPI-Severity and Interference items, weekly mean of the 24-hour worst pain and average pain scores, response rates on BPI average pain and weekly 24-hour average pain, the Patient Global Impressions of Improvement, the Western Ontario and McMaster Universities Index (WOMAC) total and subscales, Clinical Global Impressions of Severity, health survey Short Form-36 (SF-36) and EuroQoL Questionnaire – 5 Dimension.
Serotonin and norepinephrine in the brain and spinal cord are believed to both mediate core mood symptoms and help regulate the perception of pain. Based on preclinical studies, Cymbalta is a balanced and potent reuptake inhibitor of serotonin and norepinephrine that is believed to potentiate the activity of these chemicals in the central nervous system (brain and spinal cord). While the mechanism of action of Cymbalta is not known in humans, scientists believe its effects on depression and anxiety symptoms, as well as its effect on pain perception, may be due to increasing the activity of serotonin and norepinephrine in the central nervous system.
Cymbalta is approved in the United States for the acute and maintenance treatment of major depressive disorder, the acute treatment of generalized anxiety disorder, the management of diabetic peripheral neuropathic pain and the management of fibromyalgia, all in adults (18+). Cymbalta is not approved for use in pediatric patients.
Important Safety Information
Cymbalta is approved to treat major depressive disorder and generalized anxiety disorder and manage diabetic peripheral neuropathic pain. Antidepressants can increase suicidal thoughts and behaviors in children, adolescents and young adults. Patients should call their doctor right away if they experience new or worsening depression symptoms, unusual changes in behavior, or thoughts of suicide. Be especially observant within the first few months of treatment or after a change in dose. Cymbalta is approved only for adults 18 and over.
Cymbalta is not for everyone. Patients should not take Cymbalta if they have recently taken a type of antidepressant called a monoamine oxidase inhibitor (MAOI), are taking Mellaril(R) (thioridazine) or have uncontrolled glaucoma. Patients should speak with their doctor about any medical conditions they may have, including liver or kidney problems, glaucoma, or diabetes. Patients should tell their doctor about all their medicines, including those for migraine, to avoid a potentially life-threatening condition. Taking Cymbalta with NSAID pain relievers, aspirin, or blood thinners may increase bleeding risk. They also should talk to their doctor about their alcohol consumption. Patients should consult with their doctor before stopping Cymbalta or changing the dose and if they are pregnant or nursing.
Patients taking Cymbalta may experience dizziness or fainting upon standing. The most common side effects of Cymbalta include nausea, dry mouth, sleepiness and constipation.
This is not a complete list of side effects.
For full Patient Information, visit http://www.cymbalta.com.
For full Prescribing Information, including Boxed Warning and medication guide, visit http://www.cymbalta.com.
About Eli Lilly and Company
Lilly, a leading innovation-driven corporation, is developing a growing portfolio of first-in-class and best-in-class pharmaceutical products by applying the latest research from its own worldwide laboratories and from collaborations with eminent scientific organizations. Headquartered in Indianapolis, Ind., Lilly provides answers — through medicines and information — for some of the world’s most urgent medical needs. Additional information about Lilly is available at http://www.lilly.com.
This press release contains forward-looking statements about the potential of Cymbalta for chronic pain including the management of osteoarthritis pain of the knee and reflects Lilly’s current beliefs. However, as with any pharmaceutical product, there are substantial risks and uncertainties in the process of development and commercialization. There is no guarantee that the product will continue to be commercially successful. For further discussion of these and other risks and uncertainties, see Lilly’s filings with the United States Securities and Exchange Commission. Lilly undertakes no duty to update forward-looking statements.
(1) Chappell, A, et al. Duloxetine 60 to 120 mg Once Daily Versus Placebo in the Treatment of Patients with Osteoarthritis Knee Pain. Poster presented at the American Academy of Pain Medicine Annual Meeting. 29 January 2009.
(2) Lawrence, RC, et al. Estimates of the Prevalence of Arthritis and Other Rheumatic Conditions in the United States. 2008. Arthritis and Rheumatism (58):26-35.
(3) National Pain Foundation Web site – http://www.nationalpainfoundation.org/MyTreatment/articles/Arthritis_Types.asp , accessed on 22 December 2008.
Eli Lilly and Company