CO133 Initiation of Pharmacotherapies for Newly Diagnosed Early-Onset Idiopathic Restless Legs Syndrome from 2012-2019

To assess pharmacotherapy treatment initiation among adults with new, early-onset idiopathic restless legs syndrome (RLS). This is a new user, retrospective repeated cross-sectional study using IBM MarketScan Commercial Claims and Encounters data from 2012-2019. Number of treatment episodes with ≥1 outpatient RLS diagnosis code and ≥1 RLS-related prescription filled within 60 days of diagnosis were tabulated for each calendar year. Adults with a new, early-onset (18-44 years) idiopathic RLS diagnosis were included. A one-year lookback period for new RLS diagnosis, one-year washout for new users, and presumptive idiopathic RLS criteria determined by literature were applied. Continuous insurance enrollment for one-year lookback and ≥60 days from index diagnosis date was required. Clinical characteristics and annual prevalence per 1,000 episodes (x/1,000) of monotherapy treatment are reported. There were 9,107 treatment episodes identified between 2012-2019. Patients were on average 35.5 (SD 6.68) years old and were more often female (63.8%). At time of diagnosis, frequent comorbidities were insomnia (13.1%), anxiety disorders (12.2%), depression (9.1%), hypertension (6.9%), and obstructive sleep apnea (6.8%). Pharmacotherapies initiated most often were: ropinirole (46.8%), pramipexole (25.2%), and gabapentin (21.1%). Levodopa/carbidopa (2.1%), pregabalin (1.3%), gabapentin enacarbil (0.7%), and rotigotine (0.4%) were initiated less often. Most treatments initiated were as monotherapy (97.5%). Annual prevalence of monotherapy treatment for ropinirole was 96.9/1,000 episodes in 2012 and 79.1/1,000 episodes in 2019; for pramipexole, 61.8/1,000 episodes in 2012 and 37.4/1,000 episodes in 2019; and for gabapentin, 26.5/1,000 episodes in 2012 and 45.2/1,000 episodes in 2019. Starting in 2016, gabapentin surpassed pramipexole (56.1/1,000 vs. 45.8/1,000). In this nationally representative sample of privately insured adults, pharmacotherapies initiated for newly diagnosed early-onset idiopathic RLS were predominantly FDA-approved dopamine agonists followed by off-label gabapentin. Limited use of FDA-approved gabapentinoids, pregabalin and gabapentin enacarbil, warrants further investigation of long-term RLS treatment utilization.