41%

reduction in mean IRLS total score with Horizant^® 600 mg vs placebo^1,a,b

Mean IRLS score change from baseline to week 12 for the 600 mg group (–13.8) vs placebo (–9.8): 13.8 − 9.8 = 4; 4/9.8 = 0.4081.

RLS Clinical Trial Design

RLS >

EFFICACY

Horizant^® delivered sustained improvement in RLS symptoms over 12 weeks¹

IRLS Rating Scale: Total score by visit¹

^aThis was a secondary endpoint of the study.⁸

^bThe recommended dosage of Horizant^® for RLS is 600 mg taken once daily with food at about 5 pm. A daily dose of 1200 mg provided no additional benefit compared with the 600 mg dose and caused an increase in adverse reactions.¹

References

Horizant^® [prescribing information]. Woburn, MA: Azurity Pharmaceuticals, Inc; 2022.
Cundy KC, Sastry S, Luo W, et al. Clinical pharmacokinetics of XP13512, a novel transported prodrug of gabapentin. J Clin Pharmacol. 2008;48(12):1378-1388.
Gralise [prescribing information]. Morristown, NJ: Almatica Pharma LLC.
Neurontin [prescribing information]. New York, NY: Parke-Davis Division of Pfizer Inc.
American Academy of Sleep Medicine. Treatment of Restless Legs Syndrome and Periodic Limb Movement Disorder. Published January 13, 2024. Accessed December 18, 2024. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://aasm.org/wp-content/uploads/2024/03/Treatment-of-RLS-and-PLMD-CPG.pdf
Food and Drug Administration. Orange Book: approved drug products with therapeutic equivalence evaluations [gabapentin enacarbil]. Accessed July 28, 2022. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm
Lal R, Ellenbogen A, Gidal B. Interindividual variability in the bioavailability of gabapentin enacarbil extended release in healthy adults: an analysis of data from 6 phase I studies. Ther Drug Monit. 2022;44(3):448-454.
Lee DO, Ziman RB, Perkins AT, et al; XP053 Study Group. A randomized, double-blind, placebo-controlled study to assess the efficacy and tolerability of gabapentin enacarbil in subjects with restless legs syndrome. J Clin Sleep Med. 2011;7(3):282-292.

National Heart, Lung and Blood Institute Biologic Specimen and Data Repository. Restless Legs Syndrome Rating Scale. Accessed July 28, 2022. https://biolincc.nhlbi.nih.gov/media/studies/masm/IRLS.pdf?link_time=2019-07-07_21:09:19.282153
Data on file. Azurity Pharmaceuticals, Inc.
Zhang L, Rainka M, Freeman R, et al. A randomized, double-blind, placebo-controlled trial to assess the efficacy and safety of gabapentin enacarbil in subjects with neuropathic pain associated with postherpetic neuralgia (PXN110748). J Pain. 2013;14(6):590-603.

IRLS Rating Scale: Total score by visit¹

RLS clinical trial design

The efficacy and tolerability of Horizant^® was demonstrated in a 12-week randomized, double-blind, placebo-controlled study in adults with moderate-to-severe primary RLS. Patients received Horizant^® 600 mg (n=114), 1200 mg (n=111), or placebo (n=96) once daily. Eligible patients had RLS symptoms for ≥15 nights 1 month prior to screening, RLS symptoms for ≥4 of the 7 consecutive nights during baseline, and an IRLS total scorea of ≥15 at beginning and end of baseline and had discontinued RLS treatments for ≥2 weeks prior to baseline. Patients with a history of RLS symptom augmentation or end-of-dose rebound with previous dopamine agonist treatment were excluded.^1,8

^aThe IRLS Rating Scale evaluates the range and severity of RLS symptoms across 10 factors. Score is weighted by severity: Mild (0-10), Moderate (11-20), Severe (21-30).⁹

Horizant® delivered sustained improvement in RLS symptoms over 12 weeks1

IRLS Rating Scale: Total score by visit1

References

IRLS Rating Scale: Total score by visit1

RLS clinical trial design

Horizant^® delivered sustained improvement in RLS symptoms over 12 weeks¹

IRLS Rating Scale: Total score by visit¹

IRLS Rating Scale: Total score by visit¹