Long-term safety and efficacy of rotigotine transdermal patch for moderate-to-severe idiopathic restless legs syndrome: a 5-year open-label extension study

Background: Safety and efficacy of non-ergot dopamine agonists for the treatment of idiopathic restless legs syndrome have been shown in short-term trials. We did a prospective open-label extension of a 6-week, double-blind randomised trial to assess the safety, tolerability, and efficacy of rotigotine transdermal patch for up to 5 years in patients with restless legs syndrome.

Methods: Patients (aged 18-75 years) with moderate-to-severe idiopathic restless legs syndrome were treated with once-daily rotigotine transdermal patch in 33 centres in Austria, Germany, and Spain between July 31, 2003, and April 15, 2009. The dose was titrated in weekly increments (up to 4 weeks) from 0·5 mg/24 h to a maximum of 4 mg/24 h, and was followed by up to 5 years of maintenance at the optimum dose. Primary safety outcomes included occurrence of adverse events and dropouts. Efficacy assessments were secondary and included the International Restless Legs Syndrome study group severity rating scale (IRLS). Augmentation of symptoms was assessed by means of standard diagnostic criteria and was confirmed by an international expert panel. All patients who received at least one dose of study drug were included in assessments. This study is registered with ClinicalTrials.gov, number NCT00498186.

Findings: 295 patients entered the open-label study, of whom 126 (43%) completed 5 years of follow-up. 169 (57%) patients discontinued treatment, 89 (30%) because of adverse events and 31 (11%) because of lack of efficacy. 70 patients (24%) discontinued during year 1 of maintenance. The most common adverse events were application site reactions, which occurred in 37% (106/290) of patients in year 1, 17% (38/220) of patients in year 2, 14% (27/191) of patients in year 3, and in less than 6% of patients during year 4 (8/159) and year 5 (8/147). 56 patients (19%) discontinued because of application site reactions. Mean rotigotine dose was 2·43 mg/24 h (SD 1·21) after initial titration and 3·09 mg/24 h (1·07) at the end of maintenance. Of 89 patients who discontinued because of adverse events, 28 (31%) were on 4 mg/24 h rotigotine. Mean IRLS score of patients entering the open-label study was 27·8 (SD 5·9) at baseline of the double-blind trial. In patients who completed the maintenance period, mean IRLS score was reduced from a baseline score of 27·7 (SD 6·0) by a mean of 18·7 points (SD 9·5) to a score of 9·0 (SD 9·2) at the end of maintenance. 39% (48/123) of patients who completed the trial were classified as symptom free according to the IRLS. Clinically significant augmentation was recorded in 39 patients (13%), of whom 15 (5%) were receiving a dose of rotigotine within the range approved by the European Medicines Agency (EMA; 1-3 mg/24 h) and 24 (8%) were receiving 4 mg/24 h rotigotine.

Interpretation: Rotigotine transdermal patch is generally well tolerated after 1 year and provides sustained efficacy for patients with moderate-to-severe restless legs syndrome at a stable dose for up to 5 years. Thus, rotigotine transdermal patch is an appropriate long-term treatment option for moderate-to-severe restless legs syndrome, a disorder that often requires lifelong treatment.

Funding: UCB BioSciences, on behalf of Schwarz Pharma, Ireland.