This study intends to combine the advantages of γδ T cells and PD-1 monoclonal antibody to conduct an exploratory clinical study on the safety and efficacy of PD-1 antibody armored γδ T cells (γδ T-PD-1 Ab cells) in the treatment of malignant meningioma.

This is a single-center, single-arm, phase I clinical trial to evaluate the safety and efficacy of γδ T-PD-1 Ab cells in patients with malignant meningioma. A typical 3+3 dose-escalation design will be used to determine the optimal dose level of γδ T-PD-1 Ab cells based on the incidence of dose-limiting toxicity (DLT). The initial injection dose level will start from 1×10^7 to 1×10^8 in every 2 weeks.

Inclusion Criteria:

1. The patient voluntarily signs the informed consent and can complete the follow-up examination, evaluation and treatment;

2. Age 18-70 years old (both ends included), both male and female;

3. The histopathological diagnosis was malignant solid tumor;

4. Tumor recurrence is confirmed by imaging (MRI) or re-biopsy/surgery;

5. ECOG score 0-2;

6. Expected survival ≥6 months;

7. Have received chemotherapy or targeted therapy more than 4 weeks ago;

8. Organ function requirements:

   Bone marrow function: white blood cell count≥3×109, platelets ≥70×109/L, a hemoglobin (Hb) ≥90g/L; Liver function: total bilirubin ≤1.5 times the upper limit of normal (ULN); Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤3 times ULN; Renal function: serum creatinine level ≤1.5 ULN; Coagulation function: international normalized ratio (INR) does not exceed 1.5 times the upper limit of normal, and activated partial thromboplastin time (APTT) does not exceed 1.5 times the upper limit of normal.

   Cardiac function: left ventricular ejection fraction (LVEF) > 55%

9. Pregnant women of childbearing age must have a negative serum pregnancy test within 28 days before treatment. Any fertile male and female patients must agree to use effective contraceptive methods throughout the study and for at least 12 weeks after the last study administration.

Exclusion Criteria:

1. Intolerance or allergy to any ingredient or similar drug in the treatment plan planned for this study;

2. Major organ dysfunction:

   Cardiac function: Left ventricular ejection fraction (LVEF) ≤ 55%, New York Heart Association (NYHA) grade III or IV congestive heart failure, QTc > 480 msec, other cardiac diseases as determined by the investigator to be unsuitable for inclusion.

   Liver function: Child-Pugh liver function classification C or above. Pulmonary function: Severe respiratory failure affecting other organs.

3. Uncontrolled epilepsy, severe bleeding risk (such as a recent history of cerebral hemorrhage).

4. Active and/or uncontrolled infections (such as tuberculosis, sepsis, opportunistic infections, active hepatitis B virus (HBV) or active hepatitis C virus (HCV) infection, human immunodeficiency virus (HIV) infection, Treponema pallidum (TP) infection).

5. Severe, uncontrolled systemic autoimmune or inflammatory diseases (such as systemic lupus erythematosus, rheumatoid arthritis, ulcerative colitis, Crohn's disease, and temporal arteritis, Guillain-Barré syndrome (GBS), amyotrophic lateral sclerosis (ALS)).

6. Unstable systemic diseases: unstable angina pectoris, cerebrovascular accident or transient ischemia (within 6 months before screening), myocardial infarction (within 6 months before screening), grade III or IV cardiac dysfunction, refractory hypertension (refractory hypertension is defined as: after lifestyle improvement and using appropriate doses of ≥ 4 antihypertensive drugs (including diuretics), blood pressure cannot be effectively controlled after treatment for more than 1 month and still not controlled), severe arrhythmia requiring drug treatment, hepatic arrhythmia, liver disease, kidney disease or metabolic disorders.

7. Patients with other malignant tumors.

8. Major surgeries within 4 weeks before screening that were assessed by the investigator as unsuitable for inclusion.

9. Participated in other interventional clinical studies within 30 days before enrollment.