Horizant

Treats moderate-to-severe primary Restless Legs Syndrome (RLS). NDA 22399, held by Azurity. Gabapentin Enacarbil.

As of Nov 13, 2026, NDA 22399 (Horizant), held by Azurity, was first approved by FDA on Apr 6, 2011, with 10 approved supplements and 0 published complete response letters.

First approved: Apr 6, 2011
Review: Standard
Supplements approved: 10
Complete response letters: 0

What It's For

From the FDA-approved label (Indications and Usage)

HORIZANT is indicated for: treatment of moderate-to-severe primary Restless Legs Syndrome (RLS) in adults. management of postherpetic neuralgia (PHN) in adults. 1.1 Treatment of Restless Legs Syndrome HORIZANT is indicated for the treatment of moderate-to-severe primary Restless Legs Syndrome (RLS) in adults. HORIZANT is not recommended for patients who are required to sleep during the daytime and remain awake at night. 1.2 Management of Postherpetic Neuralgia HORIZANT is indicated for the management of postherpetic neuralgia (PHN) in adults.

Full prescribing information on DailyMed ↗

Approvals and New Uses

The original application and every efficacy supplement, newest first; all 11 submissions below


Mar 27, 2013	Supplement 5Efficacy (new indication or use) · Standard review	Approved	Review Label Letter
Jun 6, 2012	Supplement 3Efficacy (new indication or use) · Standard review	Approved	Review Label Letter
Apr 6, 2011	Original applicationNew molecular entity · Standard review	Approved	Review Summary Review Letter Label

Products

2 strengths and forms


Horizant600MG · tablet, extended release;oral	Gabapentin Enacarbil	RxReference drug
Horizant300MG · tablet, extended release;oral	Gabapentin Enacarbil	RxReference drug

All 11 submissions, including labeling and manufacturing supplements


Apr 25, 2025	Supplement 14Labeling · Standard review	Approved	Letter Medication Guide Label
Apr 17, 2020	Supplement 10Labeling · Standard review	Approved	Letter Label
Apr 2, 2020	Supplement 11Labeling	Approved	Label Letter
Oct 29, 2013	Supplement 9Manufacturing · Standard review	Approved	None posted
May 1, 2013	Supplement 8Labeling · Standard review	Approved	Label Letter
Mar 27, 2013	Supplement 5Efficacy (new indication or use) · Standard review	Approved	Review Label Letter
Dec 26, 2012	Supplement 7Labeling · Standard review	Approved	Label Letter
Dec 26, 2012	Supplement 6Labeling · Standard review	Approved	Label Letter
Jun 6, 2012	Supplement 3Efficacy (new indication or use) · Standard review	Approved	Review Label Letter
Apr 18, 2012	Supplement 4Labeling · Standard review	Approved	Letter Label
Apr 6, 2011	Original applicationNew molecular entity · Standard review	Approved	Review Summary Review Letter Label

Identifiers

Application: NDA 22399
Drugs@FDA: Overview at FDA
Company: Azurity Pharmaceuticals

Approvals, supplements, products and documents come from FDA's Drugs@FDA data files, refreshed daily; Drugs@FDA lists approved applications only. Complete response letters are FDA's published letters. Drugs@FDA and FDA complete response letters