TheraRadar
Data updated: May 26, 2026

SAPROPTERIN DIHYDROCHLORIDE

Rare Disease Approved 2019-05-10

Sapropterin dihydrochloride helps patients with Phenylketonuria (PKU) manage high levels of phenylalanine in the blood. It is used for both adults and children at least one month of age who have a specific form of the condition that responds to tetrahydrobiopterin. This medication is used in combination with a diet that restricts phenylalanine intake.

Source: FDA Label • PH HEALTH

How SAPROPTERIN DIHYDROCHLORIDE Works

This drug works by providing a synthetic version of BH4, a necessary cofactor for the enzyme that converts phenylalanine into tyrosine. By activating residual enzyme activity, it improves the body's ability to metabolize phenylalanine and reduces its levels in the blood.

Source: FDA Label
11
Indications
--
Phase 3 Trials
7
Years on Market

Details

Status
Prescription
First Approved
2019-05-10
Routes
ORAL
Dosage Forms
POWDER, TABLET

SAPROPTERIN DIHYDROCHLORIDE Approval History

2020
2021
2022
2023
2024
2025
2026
Original
New Indication
New Form
Label Update
32 FDA actions from 2019 to 2026
Jan 2026 ORIGINAL
Update
Sep 2025 ORIGINAL
Update
Jun 2025 ORIGINAL
Update

What SAPROPTERIN DIHYDROCHLORIDE Treats

2 indications

SAPROPTERIN DIHYDROCHLORIDE is approved for 2 conditions since its original approval in 2019. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Hyperphenylalaninemia
  • Phenylketonuria
Source: FDA Label

SAPROPTERIN DIHYDROCHLORIDE Competitive Set

Pro

Three rings of competition based on shared molecular targets and treated indications.

Direct competitors

1

Same target(s) AND same indication — head-to-head.

Indication competitors

1

Same indication, different mechanism — what else might this patient receive?

Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

Drugs Similar to SAPROPTERIN DIHYDROCHLORIDE

3 of 4

FDA-approved drugs for similar conditions. Compare mechanisms and indications to understand treatment alternatives.

KUVAN
SAPROPTERIN DIHYDROCHLORIDE
2 shared
BIOMARIN PHARM
Shared indications:
HyperphenylalaninemiaPhenylketonuria
SEPHIENCE
SEPIAPTERIN
2 shared
PTC THERAP
Shared indications:
HyperphenylalaninemiaPhenylketonuria
ZELVYSIA
SAPROPTERIN DIHYDROCHLORIDE
2 shared
AUCTA
Shared indications:
HyperphenylalaninemiaPhenylketonuria
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Clinical Trial Registry

4 trials
Trial Sponsor ID Phase Status Title
NCT04054973 H00017202 Ph 2 withdrawn L-arginine Study for Persistent Symptoms of Schizophrenia
NCT00789568 QTC-001 Ph 1 completed A Phase 1 Study to Evaluate Effects of Sapropterin Dihydrochloride on QTc Intervals in Healthy Adult Subjects
NCT00838435 PKU-015 results posted PKU-015 Ph 3 completed Effect of Kuvan on Neurocognitive Function, Blood Phenylalanine Level, Safety, and Pharmacokinetics in Children With PKU
NCT01114737 results posted PKU-016 PKU Ascend Ph 3 completed Safety and Therapeutic Effects of Sapropterin Dihydrochloride on Neuropsychiatric Symptoms in Phenylketonuria (PKU) Patients
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Active Pipeline

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Ongoing clinical trials by development phase

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Key Completed Trials

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Completed studies with published results, ranked by significance

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Trial Timeline

Full development history with FDA approval milestones

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Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

SAPROPTERIN DIHYDROCHLORIDE FDA Label Details

Indications & Usage

SAPROPTERIN DIHYDROCHLORIDE is indicated for the treatment of Hyperphenylalaninemia; Phenylketonuria.

Looking for the branded version?

ZELVYSIA

Full clinical data, patents, trials, and competitive landscape for sapropterin dihydrochloride.

See ZELVYSIA

Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.