Ocena długoterminowego bezpieczeństwa wektorów AAV‑rh79 zawierających gen OTC i meganukleazę PCSK9 u pacjentów z niedoborem ornityny transkarbamilazy (OTC)

Enrollment and baseline Assessment

After joining the study you will undergo a series of baseline examinations. These include a physical exam, measurement of height and weight, vital signs, neurologic exam, blood safety tests (including blood count, chemistry, liver function, coagulation, and serum PCSK9), urinalysis, and a 12‑lead ecg. The purpose is to record your health status before receiving any study medication.

Administration of investigational product

You will receive a single intravenous infusion of the assigned investigational product, either ECUR-506d or ECUR-506a. the infusion is given through a vein over a period defined by the study protocol. The exact dose and infusion duration are determined by the study team and are not specified in this description.

Immediate post‑infusion monitoring

After the infusion you will be observed for a short period. Vital signs and any immediate adverse events will be recorded. Additional blood samples may be taken to assess early safety.

Long‑term follow‑up visits

You will attend regular follow‑up visits for up to fifteen years. At each visit the same set of examinations performed at baseline will be repeated: physical exam, height/weight, vital signs, neurologic exam, blood safety tests, urinalysis, and a 12‑lead ecg.

Blood, saliva, urine and feces samples will be collected at each visit to measure vector pharmacokinetics (PK) and shedding of the study virus.

Monitoring for hyperammonemic crises

If you experience a hyperammonemic crisis (elevated ammonia levels that may cause symptoms), the study will record the frequency, severity, and any hospitalisation details. During a hospital stay daily ammonia levels, length of stay, and need for intensive care unit (ICU) care will be documented.

Assessment of dietary and medication adjustments

The study will track any changes in dietary protein intake and use of scavenger medication. Dosage of scavenger drug will be recorded per body surface area (BSA). protein allowance in grams per kilogram will also be noted.

Developmental and cognitive evaluations (for children)

If you are a Child participant, age‑appropriate developmental assessments will be performed using the Bayley Scale of infant development IV (BSID‑IV) and the kaufman Assessment Battery for children – second edition normative update (kabc‑II nu).

Final study completion

The study will conclude when the last scheduled follow‑up visit is completed, no later than 2041‑06‑30. at that time all final safety data, laboratory results, and any collected samples will be analysed to assess long‑term safety of the investigational product.