Safety and Therapeutic Effects of Sapropterin Dihydrochloride on Neuropsychiatric Symptoms in Phenylketonuria (PKU) Patients
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ClinicalTrials.gov Identifier: NCT01114737 |
Recruitment Status :
Completed
First Posted : May 3, 2010
Results First Posted : February 1, 2016
Last Update Posted : February 1, 2016
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Phenylketonuria | Drug: Sapropterin dihydrochloride Drug: Placebo | Phase 3 |
Phenylketonuria (PKU) results from deficient phenylalanine hydroxylase (PAH) activity and leads to toxic phenylalanine (Phe) accumulation in patients with PKU causing mental retardation, microcephaly, delayed speech, seizures, psychiatric symptoms and behavioral abnormalities. Although for most PKU patients early initiation of dietary treatment prevents severe complications, discontinuation of dietary restrictions at an early age is associated with poor cognitive development and neuropsychiatric disorders are present even in early-treated and well controlled PKU patients.
This study, PKU-016, will be conducted in PKU patients to evaluate the therapeutic effects of sapropterin dihydrochloride on the symptoms of attention deficit hyperactivity disorder (ADHD), depression, and anxiety.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 206 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | A Double-blind, Placebo-controlled, Randomized Study to Evaluate the Safety and Therapeutic Effects of Sapropterin Dihydrochloride on Neuropsychiatric Symptoms in Subjects With Phenylketonuria |
Study Start Date : | August 2010 |
Actual Primary Completion Date : | March 2013 |
Actual Study Completion Date : | March 2013 |

Arm | Intervention/treatment |
---|---|
Experimental: Sapropterin dihydrochloride |
Drug: Sapropterin dihydrochloride
A dose of 20 mg/kg/day will be administered. Route of administration is oral (intact).
Other Names:
|
Placebo Comparator: Tablet without active ingredient |
Drug: Placebo
Placebo (tablet without active ingredient) is dosed once/day for the first 13 weeks of the study. |
- Change in Attention-Deficit Hyperactivity Disorder Rating Scale-IV (ADHD-RS) / Adult ADHD Self-Report Scale (ASRS) Total Score From Baseline to Week 13 [ Time Frame: Baseline to Week 13 ]
Effects of 6R-BH4 on symptoms of ADHD in PKU subjects who had symptoms of ADHD at screening in the subjects that had a blood Phe level reduction after treatment with 6R-BH4.
The total ADHD-RS score and the corrected total ARS score range from 0 to 54, with higher scores corresponding to worse severity of ADHD symptoms.
- Number of Participants With a Score of 1 or 2 in Global Function Evaluation (CGI-I) From Baseline to Week 13. [ Time Frame: 13 weeks ]
Effects of 6R-BH4 on global function in PKU subjects in subjects that had a blood Phe level reduction after treatment with 6R-BH4 at screening.
The CGI-I is a 7-point scale that requires the clinician to assess how much the participant's illness has improved or worsened relative to a baseline state at the beginning of the intervention and rated as: 1=very much improved; 2=much improved; 3=minimally improved; 4=no change; 5=minimally worse; 6=much worse; 7=very much worse.
- Change in Hamilton Anxiety Rating Scale (HAM-A) Score From Baseline to Week 13 [ Time Frame: Baseline to Week 13 ]
Effects of 6R-BH4 on symptoms of anxiety in PKU subjects who had a blood Phe level reduction after treatment with 6R-BH4.
HAM-A Score is a total score ranging from 0 to 56 with higher scores corresponding to worse severity of anxiety symptoms. The HAM-A has 14 items, each measuring specific anxiety symptom clusters. Each item is given a 5-point-score as: 0, absent; 1, mild; 2, moderate; 3, severe; or 4, incapacitating.
- Change in Hamilton Depression Rating Scale (HAM-D) Score From Baseline to Week 13 [ Time Frame: Baseline to Week 13 ]
Effects of 6R-BH4 on symptoms of depression in PKU subjects who had a blood Phe level reduction after treatment with 6R-BH4.
HAM-D Score is a total score ranging from 0 to 48 with higher scores corresponding to worse severity of depression. The HAM-D is a 17-item depression rating scale. Nine of the items are scored on a 5-point scale as: 0, absence of depressive symptom being measured; 1, doubt concerning the presence of the symptom; 2, mild symptoms; 3, moderate symptoms; or 4, severe symptoms. The remaining 8 items are scored on a 3-point scale as: 0, absence; 1, doubt on the presence of the symptom; or 2, clear presence of symptoms.
- Change in Clinical Global Impression-Severity (CGI-S) From Baseline to Week 13 [ Time Frame: Baseline to Week 13 ]
Effects of 6R-BH4 on global function in PKU subjects who had a blood Phe level reduction after treatment with 6R-BH4.
CGI-S is a 7-point scale that requires the clinician to rate the severity of the subject's mental illness at the time of assessment, relative to clinician's past experience with subjects who have the same diagnosis. Considering total clinical experience, a subject is assessed on the severity of mental illness at the time of rating as: 1, normal, not at all ill; 2, borderline ill; 3, mildly ill; 4, moderately ill; 6, severely ill; or 7, among the most extremely ill.
- Change in Behavior Rating Inventory of Executive Function (BRIEF) Adult-Global Executive Composite (GEC) T Score From Baseline to Week 13 [ Time Frame: Baseline to Week 13 ]
Effects of 6R-BH4 on executive function in PKU subjects who had a blood Phe level reduction after treatment with 6R-BH4.
The scoring for the GEC T Score is complex and is achieved using proprietary software designed to generate scores based on raw data collected. Higher scores suggest a higher level of dysfunction.
- Change in Behavior Rating Inventory of Executive Function (BRIEF) Parent-Global Executive Composite (GEC) T Score From Baseline to Week 13 [ Time Frame: Baseline to Week 13 ]
Effects of 6R-BH4 on executive function in PKU subjects who had a blood Phe level reduction after treatment with 6R-BH4.
The scoring for the GEC T Score is complex and is achieved using proprietary software designed to generate scores based on raw data collected. Higher scores suggest a higher level of dysfunction.
- Change in Attention-Deficit Hyperactivity Disorder Rating Scale-IV (ADHD-RS) / Adult ADHD Self-Report Scale (ASRS) Total Score From Week 13 to Week 26 [ Time Frame: Week 13 to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on ADHD through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
The total ADHD-RS score and the corrected total ARS score range from 0 to 54, with higher scores corresponding to worse severity of ADHD symptoms.
- Change in Hamilton Anxiety Rating Scale (HAM-A) Score From Week 13 to Week 26 [ Time Frame: Week 13 to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on anxiety through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
HAM-A Score is a total score ranging from 0 to 56 with higher scores corresponding to worse severity of anxiety symptoms. The HAM-A has 14 items, each measuring specific anxiety symptom clusters. Each item is given a 5-point-score as: 0, absent; 1, mild; 2, moderate; 3, severe; or 4, incapacitating.
- Change in Hamilton Depression Rating Scale (HAM-D) Score From Week 13 to Week 26 [ Time Frame: Week 13 to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on depression through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
HAM-D Score is a total score ranging from 0 to 48 with higher scores corresponding to worse severity of depression. The HAM-D is a 17-item depression rating scale. Nine of the items are scored on a 5-point scale as: 0, absence of depressive symptom being measured; 1, doubt concerning the presence of the symptom; 2, mild symptoms; 3, moderate symptoms; or 4, severe symptoms. The remaining 8 items are scored on a 3-point scale as: 0, absence; 1, doubt on the presence of the symptom; or 2, clear presence of symptoms.
- Change in Clinical Global Impression-Severity (CGI-S) From Week 13 to Week 26 [ Time Frame: Week 13 to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on global function through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
CGI-S is a 7-point scale that requires the clinician to rate the severity of the subject's mental illness at the time of assessment, relative to clinician's past experience with subjects who have the same diagnosis. Considering total clinical experience, a subject is assessed on the severity of mental illness at the time of rating as: 1, normal, not at all ill; 2, borderline ill; 3, mildly ill; 4, moderately ill; 6, severely ill; or 7, among the most extremely ill.
- Change in Behavior Rating Inventory of Executive Function (BRIEF) Adult-Global Executive Composite (GEC) T Score From Week 13 to Week 26 [ Time Frame: Week 13 to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on executive function through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
The scoring for the GEC T Score is complex and is achieved using proprietary software designed to generate scores based on raw data collected. Higher scores suggest a higher level of dysfunction.
- Change in Behavior Rating Inventory of Executive Function (BRIEF) Parent-Global Executive Composite (GEC) T Score From Week 13 to Week 26 [ Time Frame: Week 13 to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on executive function through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
The scoring for the GEC T Score is complex and is achieved using proprietary software designed to generate scores based on raw data collected. Higher scores suggest a higher level of dysfunction.
- Change in Attention-Deficit Hyperactivity Disorder Rating Scale-IV (ADHD-RS) / Adult ADHD Self-Report Scale (ASRS) Total Score From Baseline to Week 26 [ Time Frame: Baseline to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on ADHD through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
The total ADHD-RS score and the corrected total ARS score range from 0 to 54, with higher scores corresponding to worse severity of ADHD symptoms.
- Change in Hamilton Anxiety Rating Scale (HAM-A) Score From Baseline to Week 26 [ Time Frame: Baseline to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on anxiety through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
HAM-A Score is a total score ranging from 0 to 56 with higher scores corresponding to worse severity of anxiety symptoms. The HAM-A has 14 items, each measuring specific anxiety symptom clusters. Each item is given a 5-point-score as: 0, absent; 1, mild; 2, moderate; 3, severe; or 4, incapacitating.
- Change in Hamilton Rating Scale For Depression (HAM-D) Score From Baseline to Week 26 [ Time Frame: Baseline to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on depression through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
HAM-D Score is a total score ranging from 0 to 48 with higher scores corresponding to worse severity of depression. The HAM-D is a 17-item depression rating scale. Nine of the items are scored on a 5-point scale as: 0, absence of depressive symptom being measured; 1, doubt concerning the presence of the symptom; 2, mild symptoms; 3, moderate symptoms; or 4, severe symptoms. The remaining 8 items are scored on a 3-point scale as: 0, absence; 1, doubt on the presence of the symptom; or 2, clear presence of symptoms.
- Change in Clinical Global Impression-Severity (CGI-S) From Baseline to Week 26 [ Time Frame: Baseline to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on global function through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
CGI-S is a 7-point scale that requires the clinician to rate the severity of the subject's mental illness at the time of assessment, relative to clinician's past experience with subjects who have the same diagnosis. Considering total clinical experience, a subject is assessed on the severity of mental illness at the time of rating as: 1, normal, not at all ill; 2, borderline ill; 3, mildly ill; 4, moderately ill; 6, severely ill; or 7, among the most extremely ill.
- Change in Behavior Rating Inventory of Executive Function (BRIEF) Adult-Global Executive Composite (GEC) T Score From Baseline to Week 26 [ Time Frame: Baseline to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on executive function through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
The scoring for the GEC T Score is complex and is achieved using proprietary software designed to generate scores based on raw data collected. Higher scores suggest a higher level of dysfunction.
- Change in Behavior Rating Inventory of Executive Function (BRIEF) Parent-Global Executive Composite (GEC) T Score From Baseline to Week 26 [ Time Frame: Baseline to Week 26 ]
Durability of the therapeutic effect of 6R-BH4 on executive function through 26 weeks in subjects who had a blood Phe level reduction after treatment with 6R-BH4.
The scoring for the GEC T Score is complex and is achieved using proprietary software designed to generate scores based on raw data collected. Higher scores suggest a higher level of dysfunction.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 8 Years to 65 Years (Child, Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- ≥ 8 years of age
- Confirmed diagnosis of PKU
- Willing to continue current diet (typical diet for the 3 months prior to study entry) unchanged while participating in the study
- Willing and able to provide written, signed informed consent or in the case of subjects under the age of 18, provide written assent (if required) and written informed consent by a legally authorized representative after the nature of the study has been explained, and prior to any research-related procedures
- Sexually active subjects must be willing to use an acceptable method of contraception while participating in the study and for at least 30 days following the last dose of sapropterin dihydrochloride
- Females of childbearing potential must have a negative pregnancy test at screening and be willing to have additional pregnancy tests during the study. Females considered not of childbearing potential include those who have been in menopause at least 2 years, or had tubal ligation at least 1 year prior to screening, or have had total hysterectomy.
- Willing and able to comply with all study procedure
Exclusion Criteria:
- Has known hypersensitivity to sapropterin dihydrochloride or its excipients
- Subject breastfeeding at screening or planning to become pregnant (subject or partner) at any time during the study
- Use of any investigational product or investigational medical device within 30 days prior to screening, or requirement for any investigational agent prior to the completion of all scheduled study assessments
- Received sapropterin dihydrochloride within 16 weeks of randomization
- Have initiated or adjusted medication for treatment of ADHD, depression, or anxiety ≤ 8 weeks prior to randomization
- Taking medication known to inhibit folate synthesis (eg, methotrexate)
- Any condition requiring treatment with levodopa or any PDE-5 inhibitor
- Concurrent disease or condition that would interfere with study participation, compliance or safety as determined by the Investigator
- Any condition that, in the view of the Investigator, places the subject at high risk of poor treatment compliance or of not completing the study

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01114737
United States, California | |
La Jolla, California, United States | |
Los Angeles, California, United States | |
Palo Alto, California, United States | |
San Francisco, California, United States | |
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Aurora, Colorado, United States | |
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Gainesville, Florida, United States | |
Tampa, Florida, United States | |
United States, Georgia | |
Atlanta, Georgia, United States | |
United States, Illinois | |
Chicago, Illinois, United States | |
United States, Indiana | |
Indianapolis, Indiana, United States | |
United States, Massachusetts | |
Boston, Massachusetts, United States | |
United States, Minnesota | |
Minneapolis, Minnesota, United States | |
United States, New York | |
Albany, New York, United States | |
Buffalo, New York, United States | |
Rochester, New York, United States | |
United States, North Carolina | |
Chapel Hill, North Carolina, United States | |
United States, Ohio | |
Cleveland, Ohio, United States | |
United States, Oregon | |
Portland, Oregon, United States | |
United States, Pennsylvania | |
Hershey, Pennsylvania, United States | |
Philadelphia, Pennsylvania, United States | |
Pittsburgh, Pennsylvania, United States | |
United States, Tennessee | |
Nashville, Tennessee, United States | |
United States, Texas | |
Dallas, Texas, United States | |
United States, Wisconsin | |
Madison, Wisconsin, United States | |
Milwaukee, Wisconsin, United States | |
Canada, Alberta | |
Calgary, Alberta, Canada | |
Edmonton, Alberta, Canada | |
Canada, British Columbia | |
Vancouver, British Columbia, Canada | |
Canada, Manitoba | |
Winnipeg, Manitoba, Canada | |
Canada, Nova Scotia | |
Halifax, Nova Scotia, Canada | |
Canada, Ontario | |
Hamilton, Ontario, Canada | |
Kingston, Ontario, Canada | |
London, Ontario, Canada | |
Toronto, Ontario, Canada | |
Canada, Quebec | |
Montreal, Quebec, Canada |
Study Director: | Suyash Prasad, MD | BioMarin Pharmaceutical |
Responsible Party: | BioMarin Pharmaceutical |
ClinicalTrials.gov Identifier: | NCT01114737 |
Other Study ID Numbers: |
PKU-016 PKU Ascend ( Other Identifier: BioMarin Pharmaceutical ) |
First Posted: | May 3, 2010 Key Record Dates |
Results First Posted: | February 1, 2016 |
Last Update Posted: | February 1, 2016 |
Last Verified: | December 2015 |
Phenylketonuria PKU Kuvan |
Sapropterin dihydrochloride Neuropsychiatric disorder ADHD |
Phenylketonurias Brain Diseases, Metabolic, Inborn Brain Diseases, Metabolic Brain Diseases Central Nervous System Diseases Nervous System Diseases Amino Acid Metabolism, Inborn Errors Metabolism, Inborn Errors Genetic Diseases, Inborn |
Metabolic Diseases Verapamil Anti-Arrhythmia Agents Calcium Channel Blockers Membrane Transport Modulators Molecular Mechanisms of Pharmacological Action Calcium-Regulating Hormones and Agents Physiological Effects of Drugs Vasodilator Agents |