Safety and Efficacy Study Using Gene Therapy for Critical Limb Ischemia (NL003-CLI-III-1)

Inclusion Criteria:

1. Age 20 and 80 (when signing informed consent), both male and female;

2. Patients diagnosed with lower limb arterial ischemic disease based on DSA orCTA and combined with their medical history and clinical manifestations andRutherford grade 4 (resting pain) must meet the following criteriasimultaneously (if both limbs of the subject have lower limb arterial ischemicdisease, the researcher shall choose one limb for the study).Resting anklesystolic pressure (dorsal foot artery or posterior tibial artery) ≤70mmHg orABI≤0.5 or TcPO2 < 30mmHg;In the first 3 months after randomized inclusion, DSAor CTA confirmed severe stenosis (≥70%) or occlusion of superficial femoralartery or popliteal artery or inferior knee artery.

3. Chronic lower limb arterial ischemia combined with resting pain met thefollowing requirements: resting pain lasted for more than 2 weeks when theinformed consent was signed;

4. Agreed to use the basic treatment drugs as required during the trial, andrecorded the daily record of the subjects in a timely and complete manner. Thecompliance of the basic treatment drugs and the subjects' diary filling duringthe screening period was 70%.

5. Agree to use appropriate contraceptive measures during the experiment;Femalesubjects of reproductive age, blood pregnancy test negative;

6. Signed informed consent

Exclusion Criteria:

1. Patients with acute lower limb ischemia or acute exacerbation of chronic lowerlimb ischemia.

2. Vascular reconstruction (bypass or intravascular therapy) or sympatheticresection or amputation was performed within 4 weeks prior to the signing ofthe informed consent.

3. Due to surgical operation, the patient is still in the postoperative riskperiod, and the researcher judges that the patient is not suitable for thetest.

4. Main-iliac artery stenosis 70%.

5. Patients with ischemic ulcer of lower extremity.

6. NYHA classification of cardiac function is classified as grade (see annex 1 forspecific classification criteria).

7. Patients with unstable angina pectoris due to cerebral infarction, cerebralhemorrhage and myocardial infarction within 3 months before signing theinformed consent.

8. Refractory hypertension (taking three or more antihypertensive drugs, systolicblood pressure 180mmHg or diastolic blood pressure 110mmHg).

9. Proliferative retinopathy and retinopathy examination is not available.

10. Inability to accurately describe symptoms and emotions.

11. Severe liver disease with uncompensated cirrhosis, jaundice, ascites orhemorrhagic varices.

12. Current recipients of immunosuppressants or chemoradiotherapy.

13. Anti-hiv antibody positive, anti-hepatitis c antibody positive and hepatitis bsurface antigen positive (if the subject is HBsAg positive and HBV DNA inperipheral blood is combined, the researcher believes that the subject'schronic hepatitis b is stable and will not increase the risk of the subject,the subject can be selected).

14. Results of laboratory examination during screening period: hemoglobin <80g/L,white blood cell count < 3.0109 /L, platelet <75 109/L, upper limit of normalAST or ALT> 3 times, upper limit of normal serum creatinine > 2.5 times, orother laboratory examination indicators appear abnormal that researchers thinkmay affect the evaluation of test results.

15. Patients with poor blood glucose control after treatment (hemoglobin a1c >10%).

16. Previously diagnosed with malignant tumor, or any of the following test resultsdetermined by the investigator to be at risk of tumor: fecal occult bloodtest;Chest X-ray examination or chest CT examination;Alpha-fetoprotein (AFP),carcinoembryonic antigen (CEA) and ca19-9;Male subjects, prostate specificantigen test (PSA, free PSA);Female subjects, cervical smear (Pap),mammography/b-ultrasound and ca-125 examination;The investigators determinedthat additional tests were necessary to eliminate the tumor risk.

17. In the opinion of the investigators, patients with comorbidities that affectsafety and efficacy evaluation, or with a predicted survival of less than 12months.

18. Frequent drinkers within the 12 months prior to the signing of the informedconsent, i.e., those who drank more than 14 units of alcohol per week (1 unit =360 mL beer or 45 mL alcohol of 40% spirits or 150 mL wine) or substanceabusers.

19. Participate in other clinical trials within 3 months before signing theinformed consent.