The Food and Drug Administration (FDA) has just approved a new drug called Savella (milnacipran HCL) for the treatment of fibromyalgia.
Savella is categorized as an antidepressant, belonging to a class of drugs called serotonin and norepinephrine reuptake inhibitors (SNRI). Savella was developed by Forest Laboratories Inc. and Cypress Bioscience Inc., and its FDA approval is based on two clinical trials that, when combined, included 2,084 fibromyalgia patients (1,460 who took Savella and 624 who took a placebo).
An interesting aspect of these studies is that the outcome to determine whether the drug was better than a placebo was that the individual patients had to demonstrate concurrent improvement to multiple measures, including pain, the patient’s global impression of change, and physical function.
The two studies were double-blind, placebo-controlled, multicenter studies in adult patients (18-74 years of age) diagnosed with fibromyalgia. Approximately 35% of patients enrolled reported a history of depression. The first study was six months long and the second was three months long.
In each study, a greater proportion of patients in the Savella treatment arms (100 mg/day and 200 mg/day) compared with placebo experienced at least a 30% reduction in pain from baseline and also rated themselves as “very much improved” or “much improved” after 3 months. In addition, more patients treated with Savella as compared with placebo met the criteria for a treatment response as measured by concurrent improvements in pain, physical function, and patient global assessment. Some patients who rated themselves as globally “much” or “very much” improved experienced a decrease in pain as early as the first week of treatment and it persisted throughout the study. Finally, the larger 200 mg/day dose of Savella did not appear to produce greater benefit than the 100 mg/day dose.
The exact mechanism by which Savella improves the symptoms of fibromyalgia is unknown. However, some researchers believe that abnormalities in certain brain chemicals may be central to fibromyalgia, and that Savella blocks the reuptake of both norepinephrine and serotonin. These brain chemicals appear to play an important role in pain perception and sensitivity.
Savella was shown to be safe and generally well tolerated. The most frequently occurring adverse reaction was nausea. Other common adverse reactions reported were constipation, hot flush, hyperhidrosis, vomiting, palpitations, heart rate increased, dry mouth and hypertension. The majority of adverse reactions reported were mild to moderate.
The FDA has approved the administration of Savella in two divided doses per day, starting at 12.5 on the first day and increasing to 100 mg/day over a one week period: Day 1: 12.5 mg once Days 2-3: 25 mg/day (12.5 mg twice daily) Days 4-7: 50 mg/day (25 mg twice daily) After Day 7: 100 mg/day (50 mg twice daily). The recommended dose is 100 mg/day but may be increased to 200 mg/day based on patient response.
Savella is expected to be available by prescription in March, 2009.