ClinicalTrials.gov record NCT04348708

Long-Term Follow Up Study of Subjects Previously Administered HMI 102

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Sep 6, 2026

An Open-Label, Long-Term Follow Up Study of Safety and Efficacy in PKU Subjects With PAH Deficiency Previously Administered HMI 102

About this page. This page shows the study's official ClinicalTrials.gov record ↗, with added help to make it easier to understand. We explain medical terms, highlight key details in plain language, and suggest questions you may want to ask the study team.

The record is periodically copied from ClinicalTrials.gov and may lag behind changes. AI summaries are checked by software, not a clinician.Read moreShow less

The official record is written by the study sponsor and published on ClinicalTrials.gov. It may not always reflect the latest changes. Before making any decisions, please confirm important information with the study team and your own healthcare team.

Where you see "AI summary", AI was used to create a plain-language explanation and software checked it against the source. It has not been reviewed by a clinician, so it may contain mistakes or leave out important details.

StatusEnrolling by invitationThe study enrols only people the study team invites, for example patients already at a particular clinic. It is not open to the public.The registry record was last updated on Jun 30, 2022, about 4 years ago, so the status shown may be out of date. The study team or the registry can confirm.

Study typeObservationalA study in which researchers do not assign participants to a treatment or other intervention. They observe or measure what happens, which may include study visits, tests, questionnaires or a review of medical records.

Age18 years old to 55 years old

SexAll

LocationUnited States

AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This is an open-label, prospective follow-up study of people with PAH deficiency (PKU) who were previously given a single intravenous dose of HMI-102. It monitors safety and efficacy measures over time, including adverse events, blood phenylalanine levels, diet status, quality of life, and protein intake, for up to five years. Participants are observed and assessed rather than given additional study treatments.

What it is studying. The study is testing long-term safety and effects after a prior single IV dose of HMI-102 in people with PAH deficiency. It records incidence and severity of adverse events related to HMI-102 and tracks plasma phenylalanine, use of a Phe‑restricted diet, quality of life (PKU-QOL), and protein intake over time.

What the researchers hope to learn. To measure the incidence and severity of adverse events of special interest and serious adverse events related to HMI-102; to track plasma phenylalanine concentrations, use of a Phe-restricted diet, quality of life (PKU-QOL), and protein intake from baseline through up to five years.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

An Open-Label, Long-Term Follow Up Study of Safety and Efficacy in PKU Subjects with PAH Deficiency Previously Administered HMI 102

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Genetic: HMI-102

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

Subject was previously administered HMI 102.
Subject is able to understand the purpose and risks of the study and is willing to provide informed consent.
Subject is able to comply with all study procedures and long-term follow-up.

Exclusion criteria

Participation in the study is not in the subject's best interest, in the opinion of the Investigator.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

This Long-Term Follow Up Study will evaluate the safety and efficacy of PKU Subjects with PAH Deficiency Previously Administered HMI 102. Subjects will have already received a single dose of HMI-102 administered intravenously

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This is a long-term follow-up study (observational) after prior HMI-102 dosing. Participants will have periodic visits for safety monitoring and efficacy assessments through baseline to year 5, including reporting adverse events, blood draws to measure plasma phenylalanine, diet and protein-intake assessments, and completing the PKU Quality of Life (PKU‑QOL) questionnaire. The record does not list additional invasive procedures beyond these assessments.

How the study is structured. An open-label, prospective observational cohort study. People who already received one IV dose of HMI-102 are followed over time with regular assessments; the study does not assign new treatments.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

This is an observational study, so the study itself gives no treatment. What would taking part involve for me, and would it change my usual care?
The registry says participants are enrolled by invitation. Who decides who is invited, and how?
The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
Which of the eligibility criteria would need to be checked with tests before I could join?

More on phenylketonuria

Clinical trials38 trials listed for phenylketonuriaEvery trial the registry lists for phenylketonuria, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in phenylketonuria researchLatest monthly update: September 2026. Includes: Diet supply gaps. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start: Aug 19, 2020
Primary completion: Jan 30, 2026 (estimated)
Study completion: Dec 1, 2026 (estimated)
Target enrollment: 21 participants (estimated)
Last updated on registry: Jun 30, 2022
Data verified: Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor: Homology Medicines, Inc

Participating sites (2)

Boston Children's Hospital
Boston, Massachusetts, 02115 · United States
Icahn School of Medicine at Mount Sinai
New York, New York, 10029 · United States

Terms used on this page · explanations by MedicalUpdates.ai

Open-Label: No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
Follow Up: The period after treatment or enrolment during which participants are observed or contacted, for example to record side effects or outcomes.
informed consent: The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
long-term follow-up: Observation that continues for years after the study treatment, often required for gene and cell therapies.
Inclusion Criteria: The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria: The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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