NK Cell Injection for Advanced Solid Tumors

Inclusion Criteria:

1. Age 18 to 75 years (inclusive), regardless of sex;
2. Histologically or cytologically confirmed advanced solid tumor;
3. Failed standard treatment, or no standard treatment available, or standard treatment not currently applicable;
4. At least one measurable lesion per RECIST 1.1 (non-lymph node lesion \>= 1.0 cm in long diameter, or lymph node lesion \>= 1.5 cm in short diameter); lesions previously treated with local therapy (e.g., radiotherapy or interventional therapy) cannot be considered target lesions unless there is imaging evidence of definitive progression;
5. Adequate bone marrow and organ function:

   * ANC \>= 1.5 x 10\^9/L;
   * Platelet count \> 100 x 10\^9/L;
   * Hemoglobin \>= 9 g/dL;
   * Total bilirubin \< 1.5 x ULN; ALT and AST \< 3 x ULN (for liver metastases or primary hepatocellular carcinoma: total bilirubin \< 2.5 x ULN, ALT and AST \< 5 x ULN);
   * Serum creatinine \<= 1.5 x ULN;
   * PT, APTT, INR \< 1.5 x ULN;
6. ECOG performance status 0-1;
7. Expected survival \>= 3 months;
8. Women of childbearing potential must have a negative serum pregnancy test within 7 days prior to cell infusion, and must agree to use reliable contraception during the study and for 6 months after cell infusion; male participants with partners of childbearing potential must agree to use reliable contraception during the study and for 6 months after cell infusion;
9. Willing to participate voluntarily and sign the informed consent form (ICF), and able to comply with follow-up requirements.

Exclusion Criteria:

1. Other malignancies within 5 years prior to screening (except completely resolved carcinoma in situ and malignancies judged by the investigator to be slow-progressing);
2. History of leptomeningeal metastasis or CNS metastasis, or definite CNS underlying disease with significant residual symptoms within 6 months prior to cell infusion (asymptomatic brain metastasis or stable symptoms after treatment without corticosteroid use may be allowed);
3. Clinically symptomatic moderate to severe third-space effusion requiring therapeutic drainage (except for minimal effusion on imaging without clinical symptoms);
4. Severe cardiovascular disease history, including but not limited to: severe arrhythmia or conduction abnormalities requiring clinical intervention; QTcF \> 450 ms (male) or \> 470 ms (female); acute coronary syndrome, congestive heart failure, aortic dissection, stroke, or other \>= Grade 3 cardiovascular events within 6 months prior to screening; NYHA functional classification \>= II or LVEF \< 50%; uncontrolled hypertension (SBP \>= 160 mmHg and/or DBP \>= 100 mmHg);
5. Any active infection (viral, bacterial, fungal) currently under treatment, or any infection requiring \>= 7 days of IV antibiotics within the past 6 weeks, or any active infection requiring oral antibiotics within the past 1 week;
6. Active autoimmune disease or history of severe autoimmune disease requiring long-term immunosuppressive therapy;
7. Allergy to lymphodepleting chemotherapy (cyclophosphamide, fludarabine) and/or any component of the study product;
8. Prior treatment with other cell therapy products (e.g., DC, CIK, T cells, NK cells, CAR-T, etc.) other than the study product;
9. Received other anti-tumor treatment (chemotherapy, targeted therapy, immunotherapy, interventional therapy, or Chinese patent medicine with anti-tumor indications) within 4 weeks prior to infusion;
10. Participated in other clinical trials within 3 months prior to infusion;
11. Toxicity or complications from prior intervention or treatment not resolved to Grade 2 or below (except alopecia and \<= Grade 2 peripheral sensory neuropathy);
12. Untreated chronic active hepatitis B, or chronic HBV carrier with HBV DNA \>= 1000 copies/mL; HCV antibody positive and HCV-RNA positive; HIV antibody positive; Treponema pallidum antibody positive;
13. Other severe organic diseases or psychiatric disorders;
14. Pregnant or lactating women;
15. Any other condition that, in the investigator's judgment, makes the participant unsuitable for this clinical study.