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Research Announcements

Posted September 18, 2023

Validation of the Phenylketonuria Symptom Severity and Impacts Scale (PKU-SSIS) v2.0 in Adolescents with PKU

BioMarin Pharmaceutical Inc. developed the Phenylketonuria Symptom Severity and Impacts Scale (PKU-SSIS), a self-administered disease-specific measure to understand the experience of people with PKU and its impacts on their everyday life. The PKU-SSIS Version 2.0 was recently adapted for adolescents (ages 12 to 17 years, inclusive) with PKU.  This study aims to conduct online surveys with 75 to 100 adolescents with PKU and their parents/guardians at two timepoints (10 to 14 days between timepoints) to validate the PKU-SSIS Version 2.0 for use in the adolescent PKU population.


Do you treat or manage adolescents with PKU who could be eligible for this study (please see who may or may not qualify below)? If so, you can help with recruitment by:

  • Informing adolescents with PKU and their parents/guardians about the study; and
  • Sharing the study link or QR code provided below with your adolescent with PKU and their parents/guardians.

Who may qualify:

  • Adolescents (ages 12 to 17 years, inclusive) and their parent/guardian
  • Adolescents diagnosed with PKU
  • Adolescents and their parent/guardian who have access to internet and access to an electronic device (e.g., computer/laptop, tablet) to complete an online survey
  • Adolescents currently managing their PKU with diet, medical food, or pharmacological therapy
  • Adolescents and their parent/guardian who reside in the United States

Who may not qualify:

  • Adolescents or their parent/guardian who have any limitation that might preclude them from participating in up to a 60-minute online survey
  • Adolescents enrolled in Study to Evaluate the Safety and Efficacy of Pegvaliase in Adolescents (Ages 12-17) With Phenylketonuria (PEGASUS)
  • Adolescent or their parent/guardian who reside outside the United States


This above information is intended for HCPs only. Please share the study link or QR code with interested patients



Clinical Outcomes Solutions, a healthcare research company, is conducting this study on behalf of BioMarin Pharmaceutical Inc. For any questions about the study or the survey link and QR code above, feel free to contact Natasha Schumacher at or by phone at +1 (520) 325-9510.

Please share the study link or QR code with interested patients

Click HERE to view PDF version of this information



Posted May 17, 2023

PKU Study Recruiting Participants in the U.S

Do you have adolescent PKU patients who are eligible for this PKU Adolescent Pegvaliase study? If so, please help recruit by informing potential participants.

PEGASUS study (165-306): PEGvaliase: A Study of Use in adolescents

This clinical trial for adolescents with PKU is enrolling patients.  Please see below qualifications:

Who may qualify:

  • Adolescents aged 12–17 years old (12 years of age at the time of consent)
  • Diagnosed with PKU and unable to maintain blood Phe levels below 600 micromol/L their current prescribed treatment and prior sapropterin dihydrocholoride use
  •  Average blood phe concentration > 600 micromol/L over the last 12 months
  • Participants must have an adult caretaker (age 18 and older) willing to observe the participant during pegvaliase injection and for a minimum of 1 hour following all pegvaliase injections during the study period

Who does not qualify:

  • Adolescents previously treated with pegvaliase
  • Adolescents who have used any medication intended to treat PKU within 14 days of the start of pegvaliase
  • Adolescents who are unable to identify and/or communicate to others that they are experiencing symptoms of potential anaphylaxis (a severe allergic reaction to the medication), due to cognitive impairment or other reasons Please speak with your child’s PKU healthcare team to find out more information

Links to the study website and to with more information on the study inclusion criteria, as well as contact information for sites are listed below

 Study Website (link) - 165-306 Pegasus Study Website

 Link to Clinicaltrials.Gov (link) -

 If you have questions, feel free to reach out to your BioMarin MSL or to Bridget Wardley (


Posted May 1, 2023

Jnana Therapeutics is developing a novel, orally administered medication for the potential treatment of PKU. SLC6A19 is the neutral amino acid transporter which is responsible for reabsorption of Phe from the proximal renal tubule and absorption of Phe in the small intestine. JNT-517 is an investigational oral small molecule inhibitor of SLC6A19 and is designed to block renal Phe reabsorption resulting in potentially increased urinary Phe excretion.

A Phase 1b clinical trial (JNT517-101) is being conducted of JNT-517 to assess the safety, tolerability, and effect on urine and blood levels of neutral amino acids (including Phe). The study is enrolling approximately 28 participants with PKU across 14 sites in the U.S. and Australia.

Click HERE to download flyer.


Posted March 2023

Posted March 2023

Identification of linguistic markers revealing severity of symptoms in phenylketonuria:
A novel measurement tool for clinical trials

We are reaching out to inform you of a study being conducted by Susan Waisbren, PhD, a psychologist from Boston Children’s Hospital. The National PKU Alliance is funding this study, which is a collaboration among Boston Children’s Hospital, the PheFree Consortium, and scientists from IBM Watson Research, because it aligns with our mission of advancing research for the PKU Community.

Clinical trials in conditions affecting neurocognitive functioning usually require a single outcome measure that captures meaningful benefits of a novel therapy.  In endeavors to demonstrate effects of new treatments in PKU, such a measure has eluded investigators. This is due to the heterogeneous and subtle deficits associated with PKU. Dr. Waisbren aims to evaluate a standardized instrument used to quantify parameters of verbal discourse as a means to identify linguistic markers revealing severity of symptoms in PKU.  If successful, this study will provide the basis for further validation of a critical tool for demonstrating the benefit of novel treatments.

Dr. Waisbren will recruit 80 adults with PKU and 80 healthy adults without PKU (parents of children with PKU). All study activities, including a Zoom session, various questionnaires, and collection of a filter paper blood specimen (the latter in PKU patients only), will be conducted virtually.

If you are interested in this study for your adult patients with PKU or caregivers of your pediatric patients with PKU, please contact Dr. Susan Waisbren at or share the flyer with your patients.


Posted October 2022

Patient-Centered Research Opportunity Aims to Personalize and Optimize Diet Treatment for Adults with Classical PKU

We are reaching out to inform you of a study being conducted by Dr. Shoji Yano, a clinical geneticist, and Kathryn Moseley, metabolic dietitian. The NPKUA is sponsoring the University of Southern California (USC) Keck School of Medicine in this research trial through our Research Grant Program because it meets the organization’s mission to improve the lives of adults with PKU.

This patient-partnered clinical trial is part of Dr. Yano and Kathryn Moseley’s ongoing research program with a broader goal to develop the long anticipated custom-tailored PKU diet treatment—to personalize and optimize the diet for adults.

The study aims to identify individual adults who may benefit clinically from addition of a large neutral amino acid (LNAA)-enriched medical food to their current diet plan. A body of evidence supports that additional dietary LNAAs block Phe uptake from blood to brain and improve neuropsychological function and quality of life in adult patients. Blood Phe concentrations, LNAA doses, and patient types most responsive to potential benefits of the dietary intervention are uncertain. This trial aims to clarify some of these unknowns.   

All study procedures are done from participants’ homes. A placebo-control randomized clinical trial N-of-1 research design provides all  participants with an individualized evidence-based evaluation of how well their current diet and blood levels are working for them, and whether the additional medical food may be more beneficial for them personally. Identifiable data will not be accessible to anyone until after the trial. At that time, only the participants, researchers, and the Institutional Review Board at USC will have access. Patients will be the first to receive their results when their study is completed, and they will choose whether they want to share the findings with their clinical teams.

The researchers plan to enroll 6 adults with classical PKU by December 15 with a January trial start date. Dietitians who are interested in the study for their adult patients with classical PKU, living in the U.S. with blood levels no higher than 900 µmol/L, are strongly encouraged to contact the Kathryn Moseley, M.S., R.D., Study Coordinator


Posted October 2022

Please help recruit participants in MMA and PA natural history study

Real-world natural history data are needed to better understand methylmalonic and propionic acidemia as potential new treatments are being developed.

JUMP (Journey to Understand MMA and PA) is a natural history study being conducted with rare disease online research platform AllStripes to accelerate the understanding of MMA and PA for all stakeholders – families, academia, clinicians, and industry.  JUMP is sponsored by HemoShear Therapeutics.

This short video from Kim Chapman explains the advantages of JUMP. 

Patients Participate From Home

It takes about 15-20 minutes for patients and caregivers to sign up for a private account authorizing AllStripes to retrieve and process medical records on their behalf at no cost to the patient.  Patients can access their records from their secure account.  With consent, AllStripes uses de-identified patient data to generate disease insights.

Please Contact Your Families About JUMP

Here Dr. Chapman explains who can sign up for JUMP and how you can help to enroll participants. 


Please contact your families with MMA and PA (up to 18 years of age) about joining JUMP.

You can download central IRB-approved flyers and a Q&A for you to share with families here:


Posted February 2022:



To learn more about the study or refer patients, please see (NCT04732429) to contact the nearest study site.

For families that want to learn more, the HERO website - - provides patient-friendly information For questions, please contact Chief Medical Officer Patrick Horn, MD, PhD at


Arcturus is seeking participants ≥ 18 years of age with stable OTCD to take part in an ongoing clinical safety study of ARCT-810

Arcturus Therapeutics is developing a messenger RNA (mRNA) therapy for ornithine transcarbamylase deficiency (OTCD). Using mRNA is a new and fundamentally different approach to disease management than the use of traditional ammonia chelators and diet. The investigational ARCT-810 therapy contains mRNA with instructions to make fully functional OTC in the liver, thus addressing the root cause of OTCD with the potential to correct the urea cycle defect. mRNA technology uses lipid nanoparticles (LNPs) to protect the mRNA from degradation in the blood as it is distributed to the liver. The LNPs are designed to be taken up by hepatocytes and once inside the cell, they release the mRNA which can be translated to the OTC enzyme by the cells’ natural processes. Delivery of human OTC mRNA may help normalize ammonia and the other biochemical markers of ureagenesis.

This is an early Phase Ib single-dose study designed to assess the safety, tolerability and pharmacokinetics (metabolism and clearance) of ARCT-810. As such, participants who enroll must be adults with mild, stable OTC disease and good cognitive function. This may include women with only one OTCD gene (heterozygous). The information obtained from this study may allow the progression of ARCT-810 into studies of younger and sicker patients with OTCD. ARCT-810 is not a gene therapy, i.e., there is no alteration of the recipient’s genes and there are no viral components.

For more information about the Phase Ib clinical trial of ARCT-810 visit the study page on

If you have questions or need help contacting one of the participating academic sites, please contact Manely Yafeh at

David Geller, M.D. Vice President Pulmonary & Rare Diseases Arcturus Therapeutics     


Posted May 2020:

Updated list of clinical trials



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