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Safety and Efficacy of HMI-103 in Participants With Classical PKU Due to PAH Deficiency

Phase 1
Terminated
Conditions
Phenylketonurias
Phenylketonuria
PAH Deficiency
Interventions
Registration Number
NCT05222178
Lead Sponsor
Homology Medicines, Inc
Brief Summary

This is an open-label, sequential ascending dose-escalation, Phase 1 study to evaluate the safety and efficacy of a single intravenous (I.V.) administration of HMI-103, a gene editing development candidate, in adult participants aged 18 to 55 years, inclusive, with classical PKU due to PAH deficiency who have uncontrolled disease despite Phe restricted dietary management.

Detailed Description

This is an open-label, sequential ascending dose-escalation, Phase 1 study to evaluate the safety and efficacy of a single intravenous administration of HMI-103, a gene editing development candidate, in adult participants aged 18 to 55 years, inclusive, with classical PKU due to PAH deficiency who have uncontrolled disease despite Phe-restricted dietary management. Up to 3 dose levels of HMI-103 may be investigated. At a given dose level, 3 participants are planned to be enrolled and dosed. Participant dosing will be staggered.

Recruitment & Eligibility

Status
TERMINATED
Sex
All
Target Recruitment
3
Inclusion Criteria
  • Adults 18-55 years of age at the time of informed consent
  • Diagnosis of classical phenylketonuria (PKU) due to PAH deficiency
  • Four baseline plasma Phe values with a concentration of ≥ 600 μmol/L and at least one historical value ≥ 600 μmol/L in the preceding 24 months.
  • Participants must have uncontrolled classical PKU disease (despite Phe-restricted dietary management) in the judgment of the investigator and confirmed by the independent DMC at the end of the Screening period.
  • Participant has the ability and willingness to maintain their baseline diet, for the duration of the trial, unless otherwise directed
Exclusion Criteria
  • Subjects with PKU that is not due to PAH deficiency
  • Presence of anti-AAVHSC15 neutralizing antibodies
  • Participants who are well controlled on a Phe-restricted diet.
  • Hemoglobin A1c >6.5% or fasting glucose >126 mg/dL
  • Liver function tests > ULN
  • International normalized ratio (INR) > 1.2
  • Hematology values outside of the normal range
  • Previously received gene therapy for the treatment of any condition.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Intermediate Dose CohortHMI-103HMI-103 delivered IV one time
High Dose CohortHMI-103HMI-103 delivered IV one time
Low Dose CohortHMI-103HMI-103 delivered IV one time
Primary Outcome Measures
NameTimeMethod
To measure incidence and severity of Treatment Emergent Adverse Events (TEAEs) and adverse events of special interest (AESIs) of a single administration of HMI-103Baseline to Week 104
To evaluate the efficacy of HMI-103 on reduction of plasma Phe concentration at each dose levelBaseline to Weeks 24-32

Mean percent change from baseline at Weeks 24-32 in plasma Phe concentration within each dose cohort post-administration of HMI-103

Secondary Outcome Measures
NameTimeMethod
To evaluate the effect of HMI-103 on plasma Phe concentration relative to treatment guidelines for PKUBaseline to Week 104

Incidence of plasma Phe of ≤ 360 μmol/L within each dose cohort at each timepoint post-administration of HMI-103

To assess durability of responseWeeks 48-52

Incidence of plasma Phe ≤ 360 μmol/L during Weeks 48-52 post-administration of HMI-103

To assess the changes in dietary protein intakeBaseline to Week 104

Change from baseline in natural and total protein intake (g/day) at each timepoint post-administration of HMI-103

Trial Locations

Locations (2)

The Community Health Clinic

🇺🇸

Topeka, Indiana, United States

Clinic for Special Children

🇺🇸

Lancaster, Pennsylvania, United States

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