The latest results from the large, double-blind, placebo-controlled European study1,2 in 345 patients suggest that pramipexole is effective in reducing the severity of RLS symptoms, over a six-week period, and is well-tolerated. Efficacy was demonstrated in this study using two measurement criteria: the International RLS Rating Scale of severity (IRLS) and the Clinical Global Impressions – Improvement (CGI – I) scale. Results after six weeks of trial therapy showed that:
- Improvement in the IRLS was significantly greater for the pramipexole group, compared to the placebo group (adjusted mean change from baseline -12.3 vs -5.7, p= 0.0001).
- On the CGI-I scale almost two-thirds (62.9%) of patients taking pramipexole were classified as "improved" or "much improved," compared to only one-third (32.5%) of patients treated with placebo (p<0.0001).
A new subanalysis of the European study, also presented for the first time, has shown that pramipexole treatment significantly improves patients' quality of life, as measured by the SF-36 (Medical Outcomes Study 36 –Item Short Form health survey)2. This assessment test has eight sub-scales upon which patients are scored. Low scores on this scale indicate poor or worsening quality of life; high scores indicate better quality of life. After six weeks of study treatment, compared to placebo, patients treated with pramipexole had statistically significant higher scores for 'Vitality' (i.e. fatigue), 'Social Functioning' (i.e. interference with normal social activities with family, friends and others) and 'Bodily Pain' (i.e. bodily pain during the past four weeks on a six-point verbal rating scale). For the other five subscales (physical functioning, role limitations due to physical problems, role limitations due to emotional problems, general mental health, and general health perceptions), pramipexole showed an improvement on scores over placebo, but these data did not reach statistical significance. These data are important as recent studies have shown that the Quality of Life impact of RLS is comparable to that of other chronic diseases such as hypertension, diabetes, and other cardiovascular conditions.
Previous studies in RLS have suggested that pramipexole may provide rapid relief from symptoms. The efficacy and safety of pramipexole has been studied from a starting dose of 0.125mg single dose per day and up to 0.75mg single dose per day.
Two pivotal studies of pramipexole in RLS have showed significant short- and long-term efficacy versus placebo. These and other trials are part of a comprehensive clinical trial program, involving more than 1,000 patients, to assess the therapeutic potential of pramipexole in this indication. Boehringer Ingelheim, the discoverer of the molecule, has also recently submitted applications for international regulatory approval of pramipexole in the treatment of RLS.
Symptoms of RLS include an uncontrollable urge to move the legs, and unpleasant and/or painful sensations in the legs. People often describe their symptoms as feeling like they have insects or "creepy-crawlies" running through their legs or a sensation of pins and needles. Symptoms can begin or worsen during periods of rest or inactivity (for example lying down or sitting in the cinema or theatre) and often are worse at nighttime.
Pramipexole, a compound from Boehringer Ingelheim research, was jointly developed by Boehringer Ingelheim and Pharmacia Corp. (today Pfizer). Currently, pramipexole is approved in the U.S. for the treatment of the signs and symptoms of idiopathic Parkinson's disease, as monotherapy or in combination with levodopa. The most commonly reported adverse events in early and late Parkinson's disease in clinical trials were dizziness, dyskinesia, extrapyramidal syndrome, headache, insomnia, somnolence, and nausea. Hallucinations and postural (orthostatic) hypotension may occur. Patients have reported falling asleep without perceived warning signs during activities of daily living, including operation of a motor vehicle, which sometimes resulted in accidents.
Boehringer Ingelheim Pharmaceuticals, Inc.
Boehringer Ingelheim Pharmaceuticals, Inc., based in Ridgefield, CT, is the largest U.S. subsidiary of Boehringer Ingelheim Corporation (Ridgefield, CT) and a member of the Boehringer Ingelheim group of companies.
The Boehringer Ingelheim group is one of the world's 20 leading pharmaceutical companies. Headquartered in Ingelheim, Germany, it operates globally with 144 affiliates in 45 countries and nearly 36,000 employees. Since it was founded in 1885, the family-owned company has been committed to researching, developing, manufacturing and marketing novel products of high therapeutic value for human and veterinary medicine.
In 2004, Boehringer Ingelheim posted net sales of US $10.2 billion (8.2 billion euro) while spending nearly one fifth of net sales in its largest business segment, Prescription Medicines, on research and development.
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Boehringer Ingelheim Pharmaceuticals, Inc.
- Oertel W, Stiasny-Kolster K. Effective treatment of Restless Legs Syndrome (RLS) with pramipexole: Results of a 6 week, multi-centre, double blind and placebo controlled study. Presented 19 September 2005, 9th EFNS Congress, Athens, Greece; Abstract # P2205
- Leissner L et al. Pramipexole improves Quality of Life (QoL) in patients with Restless Legs Syndrome (RLS). Presented 19 September 2005, 9th EFNS Congress, Athens, Greece; Abstract # P2207
- Phillips B et al. Epidemiology of restless legs symptoms in adults. Arch Intern Med 2000; 160(14): 2137-2141