This study is aiming to evaluate the safety and efficacy of SeQuent® Please CIS in the endovascular treatment of symptomatic intracranial atherosclerotic stenosis and restenosis after interventional therapy.

This study includes 2 sub-studies, sub-study A and sub-study B, namely.

Sub-study A is a prospective, multicenter, randomized controlled, superior clinical trial to evaluate the safety and effectiveness of paclitaxel drug-releasing intracranial balloon catheter (SeQuent® Please CIS) in the treatment of symptomatic intracranial atherosclerotic stenosis.

Sub-study B is a prospective, multicenter, single-arm clinical trial designed to evaluate the safety and efficacy of paclitaxel drug-releasing intracranial balloon catheter (SeQuent® Please CIS) for the treatment of restenosis following interventional treatment for symptomatic intracranial atherosclerotic stenosis.

A total of 277 subjects are expected to be enrolled, including 252 subjects in sub-study A and 25 subjects in sub-study B. Subjects enrolled in sub-study A will be randomized into the study arm and the control arm with the ratio of 1:1. The study arm will be treated with SeQuent® Please CIS (paclitaxel drug-releasing intracranial balloon catheter), while the control arm will be treated with intracranial PTA balloon catheter. Subjects enrolled in sub-study B will all be treated with SeQuent®, Please CIS.

All subjects will be followed up till 12 month post procedure.

Inclusion Criteria:

1. Aged 18 to 80 years old (including boundary value), gender is not limited;
2. The target lesion of the patient is a symptomatic intracranial atherosclerotic stenosis lesion (applicable to Sub-study A only) or restenosis lesions after interventional therapy (applicable only to Sub-study B);
3. Symptomatic intracranial arterial stenosis (intracranial segment of internal carotid artery (Petrous segment and above), middle cerebral artery, intracranial segment of vertebral artery, basilar artery, etc.) within 6 months, the degree of stenosis of the diseased artery is between 70% and 99% (WASID method);
4. Patients with symptoms occurring more than once (symptoms refer to stroke or transient ischemic attacks) after intensive drug therapy of internal medicine (including antiplatelet therapy, antihypertensive therapy, hypoglycemic therapy and lipid-lowering therapy);
5. The intracranial arterial stenosis lesion to be treated is a single lesion;
6. Patients with at least 1 risk factor for intracranial atherosclerotic plaque, including previous or existing hypertension, hyperlipidemia, diabetes, smoking;
7. Preoperative mRS ≤ 2, and NIHSS≤8;
8. Patients whose life expectancy is greater than 12 months as assessed by the investigator.
9. Patients or their guardians can understand the trial purpose, voluntarily participate in and sign the informed consent form, and can accept follow-up visits.

Exclusion Criteria:

1. Severe calcification in the target vessel, severe distortion of the target vessel or anatomical factors that make it hard for interventional devices to be in place;

2. Ischemic symptoms are only associated with branch events;

3. Severe stenosis or occlusion of tandem extracranial or intracranial vessels at the proximal or distal end of the target vessel;

4. Angioplasty or stenting procedures is planned for extracranial vascular lesions with tandem intracranial vessels;

5. History of endarterectomy in the extracranial segment of carotid artery and vertebral artery within 30 days;

6. The target vessel has previously been treated with stenting or angioplasty or other mechanical devices (applicable to Sub-study A only); the target vessel previously treated with drug-coated balloon expansion (applicable only to Sub-study B);

7. Acute or subacute intraluminal thrombosis is found in the target vessel;

8. Imaging shows an infarct size > 1/2 of the target vessel's supply area;

9. Patients with intracranial stenosis combined with aneurysm, intracranial tumor or intracranial vascular malformation, or intracranial arterial spasm without significant stenosis;

10. Intracranial hemorrhage (cerebral intraparenchymal hemorrhage, massive subarachnoid hemorrhage, and subdural/epidural hemorrhage) within 3 months;

11. Acute or subacute ischemic stroke occurring within 2 weeks;

12. Non-atherosclerotic stenosis, such as arterial dissection, Moyamoya disease, vasculitis, radiation-induced vasculopathy, or fibromuscular dysplasia;

13. There are cardiogenic stroke or risk factors that may contribute to cardioembolism, such as fibrillation, left ventricular thrombosis or myocardial infarction within 6 weeks,;

14. Patients with abnormal coagulation function or bleeding tendency (e.g., international normalized ratio (INR) > 1.5);

15. Patients with known hypersensitivity to iodine contrast medium, paclitaxel, or iopromide;

16. Any of the following abnormal laboratory test results within 7 days prior to the interventional procedure:

    • White blood cell (WBC) count < 3 × 10^9/L
    • Neutrophil count < 1.0 × 10^9/L
    • Platelet count < 100 × 10^9/L
    • ALT or AST > 3 × upper limit of normal (ULN)
    • Serum creatinine > 3.0 mg/dL;

17. Lactating females, or females of childbearing potential with a positive serum pregnancy test result;

18. The investigator judges that the patient has a severe medical condition that may affect protocol compliance (e.g., severe infection, severe chronic obstructive pulmonary disease [COPD], malignant tumor, dementia, psychiatric illness, or uncontrolled severe hypertension, defined as systolic blood pressure > 180 mmHg or diastolic blood pressure > 110 mmHg, etc.);

19. Patients who are participating in clinical trials of other drugs or devices;

20. Blood flow-limiting dissection or residual stenosis > 50% after pre-dilation；

21. Other conditions that the investigator deems the patient unsuitable for enrollment.