HP007 Monotherapy for Relapsed or Refractory Advanced Solid Tumors

Inclusion Criteria: * Male/female, 18-75 years inclusive. * Histologically-confirmed unresectable advanced tumors (breast cancer, HNSCC, cutaneous melanoma, prostate cancer, HCC, etc.); * no effective standard therapy or disease relapse/metastasis post-standard-of-care. * ECOG PS 0-1; * expected survival ≥3 months. * At least 1 measurable lesion by RECIST 1.1. Lesion in prior radiation field must have confirmed progression ≥4 weeks post-radiation. Prostate cancer subjects must meet PCWG3 progression criteria. * At least one lesion suitable for repeated intratumoral injection. * Adequate hematopoietic and organ function: * Males and females of child-bearing potential agree effective contraception from ICF signature to 3 months after last dose. * Voluntarily sign ICF and comply with study procedures. Exclusion Criteria: 1. Past/current medical conditions * CNS or leptomeningeal metastasis. * Residual toxicity from prior anti-tumor therapy \>Grade 1 (CTCAE 6.0), except alopecia and Grade 2 peripheral neuropathy without safety risk. * Poorly controlled pleural / ascitic / pericardial effusion requiring local intervention or repeated drainage. * Active autoimmune disease or high-risk history of recurrence; organ transplant with immunosuppression. * Interstitial lung disease / non-infectious pneumonitis; pulmonary embolism within prior 12 weeks. * Severe cardio-cerebrovascular events within 6 months; QTcF ≥470 msec; LVEF ≤50%; NYHA ≥III heart failure; history of long-QT syndrome or ongoing QTc-prolonging drugs. * Uncontrolled hypertension (SBP\>160 mmHg and/or DBP\>100 mmHg) or other uncontrolled systemic diseases. * High bleeding risk / coagulation disorders: inherited/acquired bleeding-thrombotic predisposition; major bleeding within 3 months; thrombolytics within 10 days; ongoing anticoagulant/antiplatelet therapy (except heparin for CVC patency). * Immunodeficiency; history of solid-organ or hematopoietic stem-cell transplantation. * Active TB within past 5 years. * Severe infection / trauma / GI perforation / fistula / tumor vascular invasion / bowel obstruction within 4 weeks; active infection or antibiotic use within prior 2 weeks (prophylaxis allowed); unexplained fever \>38.5 ℃ (tumor-related fever may be allowed per Investigator judgment). * Other active malignancy within 3 years, except: cervical carcinoma in-situ, local basal-cell carcinoma, or malignancies cured ≥5 years without recurrence. 2. Prior medications \& treatments * Local radiotherapy completed \<1 week before first dose; \>30% bone-marrow / extensive-field radiotherapy completed \<4 weeks before first dose. * Anti-tumor therapy within 4 weeks or less than 5 half-lives (whichever shorter). * Systemic corticosteroids (\>10 mg prednisone equivalent/day) or other immunosuppressants within 14 days. * Prior immunotherapy with irAEs ≥Grade 3. * Prior systemic TLR-agonist treatment (topical TLR agonists e.g. imiquimod permitted). * Vaccination within 1 month prior to enrolment. 3. Allergy, general status \& others * Severe hypersensitivity (CTCAE 6.0 ≥Grade 3) to any investigational product component. * Active HBV / HCV, positive syphilis or HIV serology. * Participated in another interventional clinical trial within 4 weeks. * Major surgery within 4 weeks before screening or planned major surgery during study. * Alcohol / illicit-drug / substance abuse within 12 months. * Documented neurological/psychiatric disorders leading to poor compliance. * Pregnant or lactating females. * Subjects judged unsuitable by the Investigator for any other reason.