1. Willing and able to communicate with the investigator, understand and comply with trial requirements, voluntarily participate in the trial, and provide written informed consent.
2. Aged 18 years or older, regardless of gender.
3. Expected survival of at least 3 months.
4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.
5. Patients with solid tumors (breast cancer, head and neck cancer, pancreatic cancer, or brain glioma) confirmed by histology or cytology.
6. Radiographic evidence of disease progression within 12 months prior to screening (according to RECIST 1.1 criteria).
7. At least one measurable target lesion according to RECIST 1.1 criteria.
8. Positive uptake in the target lesion on ⁶⁸Ga-HT547 Positron Emission Tomography (PET) scan, with SUV ≥ 4.
9. Recovery from toxicities related to prior therapy to ≤ Grade 1 or baseline (except for alopecia, vitiligo, etc.).
10. For subjects of childbearing potential: Agreement to remain abstinent or use effective contraception (including intrauterine devices, etc.) from signing the ICF until at least 24 weeks after the last dose.
You may not be if
1. Pregnant or breastfeeding women, or women with a positive baseline pregnancy test.
2. History of severe allergic reaction to any component of the investigational drug injection.
3. Received blood transfusion within 4 weeks prior to screening to meet the enrollment criteria.
4. Received immunotherapy, chemotherapy, radiotherapy, or other anti-tumor therapy within 4 weeks prior to the first dose.
5. Received any investigational drug within 28 days prior to the first dose, or concurrent participation in another clinical study (except: participation in an observational, non-interventional study, or being in the follow-up phase of an interventional study).
6. History of other known malignancies within the past 5 years.
7. Presence of symptomatic or unstable third-space effusions (e.g., pleural effusion, ascites, pericardial effusion) requiring repeated drainage.
