Manages urea cycle disorders involving deficiencies of carbamoyl phosphate synthetase…. NDA 20573, held by Horizon Therap US. Sodium Phenylbutyrate.
As of Nov 13, 2026, NDA 20573 (Buphenyl), held by Horizon Therap US, was first approved by FDA on Apr 30, 1996, with 5 approved supplements and 0 published complete response letters.
INDICATIONS AND USAGE BUPHENYL is indicated as adjunctive therapy in the chronic management of patients with urea cycle disorders involving deficiencies of carbamoyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS). It is indicated in all patients with neonatal-onset deficiency (complete enzymatic deficiency, presenting within the first 28 days of life). It is also indicated in patients with late-onset disease (partial enzymatic deficiency, presenting after the first month of life) who have a history of hyperammonemic encephalopathy. It is important that the diagnosis be made early and treatment initiated immediately to improve survival.
| Date | Submission | Status | Documents |
|---|---|---|---|
| Apr 30, 1996 | Original applicationNew molecular entity · Priority review | Approved |
| Product | Active ingredient | Marketing |
|---|---|---|
| Buphenyl3GM/TEASPOONFUL · powder;oral | Sodium Phenylbutyrate | DiscontinuedReference drug |
| Jul 29, 2022 | Supplement 22Labeling · Standard review | Approved | |
| Aug 5, 2013 | Supplement 19Manufacturing · Priority review | Approved | None posted |
| Mar 31, 2009 | Supplement 15Labeling · Standard review | Approved | |
| Oct 9, 1998 | Supplement 2Labeling · Standard review | Approved | None posted |
| Nov 7, 1996 | Supplement 1Manufacturing · Priority review | Approved | None posted |
| Apr 30, 1996 | Original applicationNew molecular entity · Priority review | Approved |
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
