safety and tolerability of zvs101e in patients with bietti 's crystalline dystrophy

Conditions: Bietti's Crystalline Dystrophy

Summary: the purpose of the study is to evaluate the safety and tolerability of an adeno-associated virus vector expressing cyp4v2 in patients with bietti's crystalline dystrophy (bcd).

this is a single-arm, open-label, and single-center study of zvs101e in patients with bcd. a total of 6 participants will be enrolled. a retinal surgeon will administer the vector by subretinal injection. safety, efficacy and vector shedding characteristics of zvs101e are then measured over 2 years.

Eligibility criteria:
inclusion criteria: 1. willingness to adhere to protocol as evidenced by written informed consent; 2. patients with clinical diagnosis of bietti's crystalline dystrophy (bcd) (age ≥ 18 years) (the age is based on the time of signing the informed consent form); 3. genetic test confirmed to carry two pathogenic variants of cyp4v2 and carry no pathogenic mutations of other ophthalmic genetic diseases; 4. agree to use reliable barrier contraception for 2 year after administration of zvs101e; 5. the study eye must meet the following requirements: bcva between 2.3 logmar and 0.5 logmar (including 2.3 logmar and 0.5 logmar); no refractive medium turbidity that affects fundus examination; visible photoreceptor (outer nuclear) layer on a standard optical coherence tomography (oct) scan. exclusion criteria: 1. lack of sufficient viable retinal cell. specifically, if indirect ophthalmoscopy reveals less than i disc area of retina which is not involved by complete retinal degeneration, these eyes will be excluded. in addition, in eyes where oct scans of sufficient quality can be obtained, areas of retina with thickness measurements less than 100 μm, or absence of neural retina, will not be targeted for delivery of aav2-hcyp4v2; 2. existing or pre-existing of choroidal neovascular (cnv) lesions that were secondary to bcd, or other eye conditions interfering with the surgery or the interpretation of the clinical endpoint, in the investigators' opinion; 3. the study eye has been treated with other drugs within 3 months that could affect the evaluation of the investigational drug (such as ranibizumab, bevacizumab, aflibercept, conbercept); 4. the study eye has been treated with the following intraocular procedures: retinal detachment surgery, vitrectomy; 5. pre-existing eye conditions that the investigator evaluates could interfere with ocular evaluation, preclude surgery, interfere with interpretation of study endpoints or surgical complications (such as glaucoma, high refractive error, diabetes retinopathy or retinal vasculitis ); 6. currently taking or may require systemic medications that can cause ocular toxicity, such as psoralen, risedronate, or tamoxifen; 7. patient with allergic constitution (such as those allergic to two or more drugs and food); 8. those with the following laboratory abnormalities which are clinically significant: liver function: chronic liver disease, alt increased \>3 times the upper limit of normal; with uncontrolled hypertension, mean systolic blood pressure ≥ 160 mmhg or mean diastolic blood pressure ≥ 100 mmhg; with uncontrolled diabetes, hba1c\>10%; patients with abnormal coagulation function (prothrombin time ≥ upper limit of normal (3 seconds' longer), activated partial thromboplastin time ≥ upper limit of normal (10 seconds' longer)); serum virology test: active hepatitis b, hepatitis c virus antibody (hcv-ab), human immunodeficiency virus antibody (hiv-ab) or syphilis antibody positive; abnormality of tumor markers (alpha fetoprotein, carcinoembryonic antigen, ca125 carbohydrate antigen, ca153 carbohydrate antigen, ca199 carbohydrate antigen) 9. having any past or present medical history that may affect the safety of the trial or the in vivo process of the drug, especially the medical history of cardiovascular, hepatic, renal, endocrine, gastrointestinal, pulmonary, neurological, hematological, oncologic, immunological or metabolic disorders and others that are thought clinically significant by the investigator, such as diabetes, severe cardiac failure (new york heart association class iii and iv); 10. participation in any medicine or medical device clinical trials within 3 months prior to enrollment; 11. neutralizing antibodies to raav\> 1:1000 by immunologic test; 12. for females in pregnancy or lactation period; 13. any other conditions which leads the investigator to determine the participant is unsuitable for this study.