A Phase 1/Phase 2 Open-label Study to Evaluate the Safety, Tolerability, and Efficacy of a Single Intravenous Administration of SAR444836 in Adult Participants With Phenylketonuria

NCT05972629 | Active Not Recruiting Phase 1 DMC FDA Drug

• 3 other identifiers: DFI17545U1111-1271-12932022-501200-98
• Study Type: interventional
• Target: 32
• Locations: 5 countries
• Sites: 11

Brief Summary

This is a single group Phase 1/Phase 2, 1-arm, open-label study with SAR444836, an adeno-associated virus (AAV) vector-mediated gene transfer of human phenylalanine hydroxylase (PAH), for the treatment of adult participants with phenylketonuria (PKU) on a chronic, stable diet. The purpose of the study is to evaluate the safety and efficacy of SAR444836 in reducing phenylalanine (Phe) levels and in the elimination of a Phe restricted diet. Participants will receive a one-time intravenous (IV) administration of SAR444836. The study is constituted of 2 separate parts: a dose escalation part, and a dose expansion part where subsequent participants will be administered a safe and effective dose level identified during the dose escalation part. In both study parts, clinical and laboratory assessments will be collected to: a) assess the incidence of adverse events, and b) evaluate the effect of SAR444836 on reductions in blood Phe levels and maintenance of these Phe levels after elimination of a Phe restricted diet. The study duration will be for a minimum duration of 5 years following SAR444836 administration, for each participant and includes a 6-week screening phase, a 96-week treatment follow-up period after SAR444836 administration, followed by an additional 3 years of long-term safety (and efficacy) monitoring. There will be a total of 47 study visits. Many study visits may occur as remote visits and be performed by a qualified in-home service provider. Actual study duration for an individual participant may be longer than 5 years due to the administration of SAR444836 to participants in Stage 1A in a serial fashion, the duration of the screening period, and/or other factors such as delays in scheduling study visits.

Conditions

Phenylketonuria

Outcome Measures

Primary Outcomes (1)

• Incidence of treatment-emergent adverse events (TEAEs)

  From Baseline to Week 260

Secondary Outcomes (8)

• Proportion of participants with sustained plasma level of Phe<360 μmol/L for ≥4 weeks without dietary Phe restriction at Week 24, 48, and Week 96 or Early Termination Visit following SAR444836 administration

  From Baseline to Week 96

• Change from baseline in plasma level of Phe at Week 24, 48, and Week 96 or Early Termination Visit following SAR444836 administration

  From Baseline to Week 96

• Change from baseline in dietary protein intake at Week 24, 48, and Week 96 or Early Termination Visit following SAR444836 administration

  From Baseline to Week 96

• Proportion of participants with sustained plasma level of Phe <600 μmol/L for ≥ 4 weeks without dietary Phe restriction at Week 24, 48, and Week 96 or Early Termination Visit following SAR444836 administration

  From Baseline to Week 96

• Proportion of participants with sustained plasma level of Phe <120 μmol/L for ≥ 4 weeks without dietary Phe restriction at Week 24, 48, and Week 96 or Early Termination Visit following SAR444836 administration

  From Baseline to Week 96

Study Arms (1)

SAR444836

EXPERIMENTAL

Participants will receive a single dose of SAR444836 on Day 1

Drug: SAR444836

Interventions

SAR444836 DRUG

Infusion pump, intravenous infusion (IV)

SAR444836

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult males, and females of non-childbearing potential, 18-65 years of age at the time of informed consent.
• Participants must have uncontrolled classical PKU due to PAH deficiency (despite Phe-restricted dietary management or Palynziq) in the judgement of the Investigator.
• Two historical plasma Phe values ≥ 600 μmol/L in the preceding 12 months while on Phe restricted diet therapy. Two plasma Phe values ≥ 600 μmol/L drawn at least 72 hours apart during the screening period while on Phe restricted diet therapy in the absence of an acute illness.
• Participant has the ability and willingness to maintain their present diet for the duration of the Post-treatment Follow-up Phase (through Week 96), unless otherwise directed as per protocol
• Body mass index (BMI) ≤ 35 kg/m2
• Willingness to use effective methods of contraception.
• Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.

You may not qualify if:

• Presence of neutralizing antibodies against the AAV SNY001 capsid
• Abnormal liver function laboratory testing evidenced by alanine aminotransferase (ALT)\>1.5X upper limit normal (ULN), aspartate transaminase (AST)\>1.5X ULN, alkaline phosphatase \>1.5X ULN, Total and direct bilirubin \>1.5X ULN (bilirubin levels above the laboratory's normal range are acceptable in individuals with a documented history or laboratory evidence of Gilbert's Disease)
• Any significant underlying liver disease or any of the following documented diagnoses, indicative of significant underlying liver disease:
• Portal hypertension; or
• Splenomegaly; or
• Hepatic encephalopathy
• Serum albumin measurement below the lower limit of normal of the laboratory OR AST-to-Platelet Ratio Index \> 1.0
• Serum creatinine \>1.5X ULN
• Hemoglobin A1c \>6.5% or fasting glucose \>126 mg/dL
• Screening laboratory testing demonstrating any of the following:
• HIV; or
• active or prior hepatitis B virus (HBV) infection defined as positive test for hepatitis B surface antigen (HBsAg) or positive test for hepatitis B core antibody (total HBcAb) or detectable HBV DNA; or
• active hepatitis C virus (HCV) infection defined as positive test for hepatitis C antibody followed by detectable HCV RNA or if a participant is presently receiving (or has received within 6 months prior to screening) anti-viral therapy for hepatitis C
• Clinically significant, active bacterial, viral, fungal, or parasitic infection (based on Investigator's judgement)
• The above information is not intended to contain all considerations relevant to a potential participation in a clinical trial.

Sponsors & Collaborators

• Sanofi: lead

Study Sites (11)

University of California San Francisco- Site Number : 8400007

San Francisco, California, 94143, United States

Location

Children's Hospital IMD Clinic- Site Number : 8400015

Aurora, Colorado, 80045, United States

Location

University of Florida-Genetics- Site Number : 8400010

Gainesville, Florida, 32610, United States

Location

UHCMC- Site Number : 8400014

Cleveland, Ohio, 44106, United States

Location

UPMC Children's Hospital of Pittsburgh-4401 Penn Ave- Site Number : 8400018

Pittsburgh, Pennsylvania, 15224-1334, United States

Location

Medical University of SC- Site Number : 8400004

Charleston, South Carolina, 29425, United States

Location

University of Texas- Site Number : 8400002

Houston, Texas, 77030, United States

Location

Investigational Site Number : 0320002

Ciudad Autonoma Buenos Aires, Buenos Aires, 1199, Argentina

Location

Hospital de Clinicas de Porto Alegre - HCPA- Site Number : 0760001

Porto Alegre, Rio Grande do Sul, 90035903, Brazil

Location

Investigational Site Number : 3760001

Tel Litwinsky, 52621, Israel

Location

Investigational Site Number : 7920001

Ankara, 06560, Turkey (Türkiye)

Location

Related Links

• DFI17545 Plain Language Results Summary

MeSH Terms

Conditions

Phenylketonurias

Condition Hierarchy (Ancestors)

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; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Officials

• Clinical Sciences &amp; Operations

  Sanofi

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 23, 2023
• First Posted: August 2, 2023
• Study Start: August 7, 2023
• Primary Completion (Estimated): April 2, 2030
• Study Completion (Estimated): April 2, 2030
• Last Updated: September 23, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will share

Locations

IL (1); BR (1); AR (1); US (7); TU (1)