This is a non-randomized，open-label，controlled multi-center Phase Ⅰ study to evaluate tolerability, pharmacokinetics, and preliminary efficacy of BM201 injection in combination with radiotherapy in patients with histologically or cytologically confirmed unresectable locally advanced or metastatic solid tumors who have failed standard therapy or are unable to receive standard treatment.

This is a Phase I, open-label clinical study primarily designed to evaluate the safety and tolerability of BM201 injection in combination with radiotherapy in patients with advanced solid tumors.

Inclusion Criteria:

1. Unresectable advanced or metastatic solid tumors, either refractory to standard therapy or ineligible for standard treatment.
2. ECOG performance status score of 0-2 point;
3. Expected survival of ≥3 months.
4. At least one measurable lesion by irRECIST criteria, and eligible for intratumoral injection.
5. Prior anti-tumor treatments should be paused for at least 4 weeks before trial initiation，with toxicity related to anti-cancer treatment recovered to ≤Grade 1.
6. Adequate organ and bone marrow function

Exclusion Criteria:

1. Patients with active brain metastasis and/or leptomeningeal carcinomatosis，exempt for asymptomatic brain metastases or stable metastatic lesions for a minimum of 4 weeks.
2. Allergic: History of hypersensitivity to active ingredients or any other components of the study medication; cumulative two or more allergies to contrast agents, other drugs, or food.
3. Active hepatitis B or positive antibodies for hepatitis C, human immunodeficiency virus (HIV), or syphilis.
4. Severe cardiac or cerebrovascular conditions, uncontrolled diabetes, hypertension not well-managed medically (systolic >140 mmHg and/or diastolic >90 mmHg), serious infections (active within 14 days before first drug administration/radiotherapy), active GI ulcers, and immune dysfunction.
5. Presence of other active malignancies or history thereof, except for previously managed non-invasive skin basal or squamous cell carcinomas with a 5-year recurrence-free interval, cervical carcinoma in situ, and ductal carcinoma in situ of the breast.
6. Uncontrolled third-space effusions such as pericardial, abdominal, or pleural within 2 weeks before the initial treatment.
7. Administration of corticosteroids within the preceding 2 weeks before initial treatment.
8. Receipt of vaccination within 2 weeks prior to initial therapy.
9. Participation in clinical trial involving drugs or biologics within 4 weeks before the initial treatment.
10. History of major surgery within 3 months prior to initial treatment or scheduled major surgery during the clinical trial period.
11. Prior blood donation or major hemorrhage (>450 mL) within 3 months before initial therapy, or intention to donate blood/blood components during or within 3 months after the trial.
12. Patients with difficult venous access or intolerance to venipuncture, and those unable to tolerate intratumoral injection.
13. Pregnant (positive pregnancy test) and lactating females.
14. Subjects planning pregnancy or gamete donation within 3 months post-consent and unwilling to practice effective contraception.
15. Patients deemed ineligible for enrollment by the investigator.