KXV01 Injection in Patients With Advanced Solid Tumor (Including Osteosarcoma and Sarcoma)

Screening Period 1 Inclusion Criteria 1: 1. Voluntarily participate in the clinical study; fully understand the study and voluntarily sign the informed consent form; be willing to comply with and able to complete all trial procedures. 2. Aged 18 to 70 years (inclusive). 3. Histologically or cytologically confirmed incurable or metastatic solid tumors that have failed standard treatment, or for which no standard treatment is currently available. 4. Expected survival time \> 6 months. 5. ECOG performance status of 0 or 1. 6. Sufficient organ function. 7. Patients whose tumor lesions can be collected and from whom tumor-reactive TCR sequences can be identified may enter the study. 8. Women of childbearing age must have a negative urine/blood pregnancy test during the screening period and agree to use contraceptive measures for at least 1 year after administration; male subjects whose partners are of childbearing potential must agree to use effective barrier contraception for at least 1 year after administration. Exclusion Criteria 1: 1. A history of other malignant tumors within 2 years prior to signing the informed consent form, except for non-melanoma skin cancer, some in situ carcinomas (e.g., cervical cancer, bladder cancer, breast cancer), or low-risk prostate cancer. 2. Uncontrolled infectious diseases within 4 weeks prior to signing the informed consent form. 3. Active hepatitis B or hepatitis C virus infection. 4. Patients with HIV infection. 5. Patients with positive Treponema pallidum. 6. A history of any of the following cardiovascular diseases within the past 6 months: New York Heart Association (NYHA) Class III or IV heart failure, coronary angioplasty or stenting, myocardial infarction, unstable angina, or other clinically significant heart diseases. 7. Tumor lesions invading the heart or major blood vessels. 8. Abnormal pulmonary function indicated by a ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) \< 70% in pulmonary function tests. 9. A history of clinically significant central nervous system (CNS) disorders, including but not limited to epilepsy, paresis, aphasia, stroke, severe traumatic brain injury, dementia, Parkinson's disease, cerebellar disease, and organic brain syndrome. 10. Females who are pregnant or breastfeeding. 11. A history of primary immunodeficiency or autoimmune disease. 12. Patients whose disease or condition renders them unable to understand, participate in, and/or comply with the study protocol. 13. Any other disease that the investigator believes would impair the subject's ability to tolerate protocol treatment or significantly increase the risk of complications. 14. Current or past history of psychoactive substance abuse or dependence. 15. Subjects whose underlying condition, in the investigator's judgment, may increase the risk of receiving the investigatory drug or confound the interpretation of toxic reactions and adverse events. 16. Other conditions deemed unsuitable for participation in the study by the investigator. Screening Period 2 Inclusion Criteria 2: The patient's organ function and key test items at this stage should not have significant changes compared with their test results in Screening Period 1. If the patient's test results in Screening Period 2 exceed the following criteria, they should not receive administration of KXV01 Injection until the abnormal items return to the normal range. 1. The patient's KXV01 Injection has been successfully prepared. 2. Expected survival time \> 6 months. 3. ECOG performance status of 0 or 1. 4. Sufficient organ function. 5. Females of childbearing potential have a negative blood pregnancy test within 7 days prior to administration of the study drug (Non-childbearing potential: surgically sterilized or postmenopausal for at least 2 years). In addition, female subjects of childbearing potential must use medically approved contraceptive measures for 12 months after the start of study treatment and have no egg retrieval during this period. 6. Male subjects are willing to use medically approved contraceptive measures from the time of signing the informed consent form until 12 months after the start of study treatment, and will not donate sperm during this period. 7. At least one measurable lesion according to RECIST v1.1 criteria. 8. Toxicities and adverse reactions caused by prior therapy should have resolved to Grade ≤ 1 (except for toxicities considered clinically insignificant, such as chemotherapy-induced alopecia). Exclusion Criteria 2: 1. Prior to administration of the study drug, the subject's anti-tumor therapy has not been sufficiently washed out (2 weeks or 5 half-lives, whichever is shorter). 2. Uncontrolled infectious diseases within the previous 4 weeks. 3. Active hepatitis B or hepatitis C virus infection. 4. Patients with HIV infection. 5. Patients with positive Treponema pallidum. 6. Tumor lesions invading the heart or major blood vessels. 7. A history of clinically significant central nervous system (CNS) disorders, including but not limited to epilepsy, paresis, aphasia, stroke, severe traumatic brain injury, dementia, Parkinson's disease, cerebellar disease, and organic brain syndrome. 8. Known primary central nervous system (CNS) malignancy or symptomatic CNS metastases. 9. Use of the restricted drugs or treatments between Screening Period 1 and Screening Period 2 per the protocol. 10. Females who are pregnant or breastfeeding. 11. Subjects whose underlying condition, in the investigator's judgment, may increase the risk of receiving the investigatory drug or confound the interpretation of toxic reactions and adverse events. 12. Receipt of major surgery (excluding diagnostic surgery) between Screening Period 1 and Screening Period 2, or expected to undergo major surgery during the study period. Subjects with planned or ongoing minor surgical procedures (such as venous access placement, etc.) are eligible for enrollment.