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Enrolling by invitationPhase 2

Sirolimus for people with Leigh syndrome caused by a confirmed gene change

Tests sirolimus for safety and effect in people with Leigh syndrome.

Key facts

Who runs it
Matthew Demczko
Where
Philadelphia, United StatesSee the site
Trial code
Registry title
Sirolimus for Leigh Syndrome
Status
Enrolling by invitation
Phase
Phase 2
People taking part
15 people, planned
Started
27 Feb 2025
Expected to end
Dec 2027
Type of study
Interventional, 2 groups
Treatments tested
  • Sirolimus
Record updated
31 March 2026

Who can take part

Age
6 months to 55 years
Sex
Women and men
Healthy volunteers
Cannot take part

The registry criteria, word for word

Show all 34 criteriaShow less

Who can take part

  • Genetically-confirmed diagnosis of Leigh syndrome with neurodevelopmental manifestations, which include documented developmental delay, developmental regression, or abnormal neurologic exam findings including but not limited to hypotonia, hypertonia, dystonia, chorea, nystagmus, ataxia, dysmetria, tremor or muscle weakness
  • Age 6 months to 55 years at the time of enrollment
  • Weight ≥ 5 kg at the time of enrollment
  • Adequate liver function as evidenced by total bilirubin < 1.5x upper limit of normal (ULN) and liver function tests, alanine transaminase (ALT) and aspartate aminotransferase (AST), < 3x ULN
  • Adequate renal function as evidenced by glomerular filtration rate (GFR) > 60 mL/min/1.73m2 (cystatin C for pediatric population)
  • Normal hematologic parameters as defined as:; Absolute neutrophil count (ANC) ≥ 1.0 x 109/L; Platelet count ≥ 100,000/mm3 (100 x 109/L); Hemoglobin ≥ 9 g/dL
  • Non-fasting serum triglycerides and cholesterol < 300 mg/dL
  • Serum amylase and lipase < 2x ULN
  • Adequate immunoglobulin levels as outlined below that, in the opinion of the investigator, will not place the patient at increased risk of infection; Immunoglobulin G (IgG) ≥ 200 mg/dL; Immunoglobulin M (IgM) ≥ 30 mg/dL; Immunoglobulin A (IgA) ≥ 10 mg/dL
  • All sexually active participants must agree to use effective contraception:; Females of child-bearing potential must agree to use effective contraception without interruption from 28 days prior to starting Investigational Product (IP) throughout 3 months after last dose of IP and have a negative urine pregnancy test result at screening and agree to ongoing pregnancy testing during the course of the study; Male patients must practice abstinence or agree to use a condom during sexual contact with a pregnant female or a female of childbearing potential while participating in the study and throughout 3 months after the last dose of investigational drug
  • The patient or parent(s)/legal guardian(s) is/are willing and able to comply with the study visit schedule and other protocol requirements, in the opinion of the investigator
  • The patient or the patient's parent(s)/legal guardian(s) understand(s) and voluntarily sign(s) the informed consent documents(s) prior to any study-related assessments/procedures being conducted

Who cannot take part

  • Myocardial infarction within 6 months prior to enrollment
  • Prior history of hypersensitivity to sirolimus or other mTOR (Mechanistic Target of Rapamycin inhibitors)
  • Prior history of angioedema requiring treatment or cessation of a presumed causative agent
  • Planned surgical procedure during the study period
  • Clinically significant proteinuria that requires ongoing medical therapy
  • Treatment with any investigational drug (i.e., a drug for which there is no approved indication), including an investigational drug for mitochondrial disease within 1 month prior to receiving the first dose of study drug (or within 3 months for a trial with an investigational biologic)
  • Recent infection requiring systemic anti-infective treatment that was completed ≤ 14 days prior to enrollment
  • Use of strong inhibitors and/or inducers of cytochrome P450 (CYP) 3A4 (CYP3A4) and/or p-glycoprotein (p-GP) within the 14 days prior to receiving the first dose of study drug. Additionally, use of any known CYP3A4 substrates with a narrow therapeutic window (e.g., fentanyl, alfentanil, astemizole, cisapride, dihydroergotamine, pimozide, quinidine, terfenadine) within the 14 days prior to receiving the first dose of study drug
  • Use of medications with a high risk of angioedema
  • Patients with implanted cardiac assist/medical devices (including pacemakers), unless device was implanted prophylactically, and the patient is clinically asymptomatic
  • Symptomatic congestive heart failure (CHF), unstable angina pectoris, cardiac arrhythmia, uncontrolled hypertension, or unstable coronary artery disease
  • Confirmed or highly suspected immunodeficiency disorder(s), including but not limited to, common variable immune deficiency (CVID), complement deficiency, etc
  • Any uncontrolled psychiatric or medical condition which, in the opinion of the investigator, would interfere with the patient's participation in the study
  • History of solid organ transplant (kidney, liver, heart, lung) or bone marrow transplant
  • Patients with confirmed or suspected increased intracranial pressure, pseudotumor cerebri (PTC)/idiopathic intracranial hypertension, and or papilledema
  • Currently active malignancy (other than adequately treated non-melanoma skin cancers [i.e., squamous cell and/or basal cell carcinoma], carcinoma in situ of the cervix, or other adequately treated carcinoma in situ) and/or ongoing treatment for malignancy are ineligible. Patients are not considered to have a currently active malignancy if they have completed therapy and are free of disease for ≥ 1 year
  • History of interstitial lung disease and/or pneumonitis
  • Known human immunodeficiency virus (HIV), active hepatitis B or hepatitis C infection(s)
  • Cardiac ejection fraction ≤ 50 %, shortening fraction ≤ 25% on cardiac echocardiogram within one year of screening and/or severe end-organ hypo-perfusion syndrome (secondary to cardiac failure) resulting in lactic acidosis
  • Uncontrolled diabetes mellitus, as defined by HbA1c > 8%, despite adequate therapy
  • In the opinion of the investigator, clinically significant ECG and/or echocardiogram alterations at the time of screening
  • Patients who are breastfeeding or are pregnant

Where in United States

  • Children's Hospital of PhiladelphiaPhiladelphia, United StatesEnrolling by invitation

About the trial

What the trial wants to find out

The purpose of this study is to evaluate the safety and efficacy of the drug Sirolimus in participants with Leigh syndrome.

The 2 groups in the trial

  • Phase 2ATreatment being tested

    Participants will receive Sirolimus for at least 24 weeks at a starting dose of 0.8 to 1.3 mg/m2 two (2) times daily.

    Treatment: Sirolimus

  • Long-Term ExtensionTreatment being tested

    Eligible participants may continue Sirolimus treatment for up to two (2) years.

    Treatment: Sirolimus

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
A Pilot Phase 2 Study With Long-Term Extension to Assess the Safety and Efficacy of Sirolimus in Patients With Leigh Syndrome Caused by Genetically-Confirmed Mitochondrial Respiratory Chain Deficiency
Plain-language title
Sirolimus for people with Leigh syndrome caused by a confirmed gene changeGenerated from the registry record. The registry title is the official one.
Record updated
31 March 2026