Clinical Study of 68Ga-labeled Novel EPHA2 Cyclic Peptides PET/CT for Imaging of Solid Tumors

This study aims to develop novel ⁶⁸Ga-labeled EphA2-targeting cyclic peptide probes for precise diagnosis and patient selection in EphA2-positive cancers.

Inclusion Criteria: * ① Participants must voluntarily provide written informed consent and be able to complete the study in accordance with the protocol. ② Participants must be aged 18-75 years, inclusive, regardless of sex. ③ Participants must have a clinical diagnosis of cervical, ovarian, breast, lung, prostate, colorectal, or esophageal cancer, with biopsy findings serving as the diagnostic reference, and positive EphA2 expression confirmed by immunohistochemistry. ④ Participants must have at least one measurable lesion that can be accurately and reproducibly measured according to the modified Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1. ⑤ Participants must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0-3. * Hematological parameters, coagulation parameters, and hepatic and renal function must meet the following criteria, without blood transfusion, hematopoietic growth factor support, or hepatoprotective treatment to correct these parameters within 14 days before administration: * a) Hematology: White blood cell count (WBC) ≥2.5 × 10⁹/L or absolute neutrophil count (ANC) ≥1.5 × 10⁹/L; platelet count (PLT) ≥100 × 10⁹/L; and hemoglobin ≥90 g/L. * b) Coagulation: Prothrombin time (PT) or activated partial thromboplastin time (aPTT) ≤1.5 × the upper limit of normal (ULN). This criterion applies only to participants not receiving anticoagulation therapy; those receiving anticoagulation therapy must be on a stable anticoagulant dose. * c) Hepatic function: Total bilirubin ≤1.5 × ULN; alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5 × ULN; and alkaline phosphatase (ALP) ≤2.5 × ULN. * d) Renal function: Urea ≤1.5 × ULN; serum creatinine ≤1.5 × ULN; and creatinine clearance ≥50 mL/min, calculated using the Cockcroft-Gault equation. * Female participants of childbearing potential must have a negative pregnancy test. Female participants of childbearing potential and male participants of reproductive potential must agree to use effective contraception or abstain from sexual intercourse during the study. Exclusion Criteria: * ① Individuals who are unsuitable for or unable to complete PET/CT examinations for any reason, including but not limited to claustrophobia or fear of radiation. ② Individuals unable to tolerate intravenous administration, such as those with a history of fainting in response to needles or blood. ③ Individuals with known hypersensitivity to chimeric or humanized antibodies, fusion proteins, or any other excipients. ④ Individuals with any of the following conditions: * a) Brain metastases, except asymptomatic primary or metastatic brain tumors that do not require treatment; * b) Leptomeningeal carcinomatosis; * c) Poorly controlled diabetes mellitus; * d) Myocardial infarction within 6 months before screening; * e) Unstable angina; * f) A history of uncontrolled arrhythmia or a current high risk of arrhythmia; * g) Previous coronary artery bypass grafting; * h) A cerebrovascular accident within 6 months before screening; * i) Congestive heart failure (New York Heart Association functional class III-IV); * j) Pulmonary embolism; * k) Deep vein thrombosis; * l) An infection requiring intravenous antibiotic treatment within 2 weeks before screening; * m) A history of immunosuppressive therapy following organ transplantation. * Individuals with a history of or a current primary central nervous system tumor. * Individuals with acute or subacute intestinal obstruction or a history of inflammatory bowel disease. * Individuals whose toxicities from previous anticancer treatment have not resolved to grade 0 or 1 according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0, except for alopecia. ⑧ Individuals with an active autoimmune disease, a history of autoimmune disease requiring systemic corticosteroids and/or immunosuppressants, or a syndrome requiring systemic corticosteroid or immunosuppressive therapy. ⑨ Individuals with any psychiatric or cognitive condition (e.g., alcohol or drug abuse, dementia, or altered mental status), or any other condition that may impair study compliance, compromise their ability to understand the informed consent information, or, in the investigator's judgment, preclude study participation or interfere with the interpretation of study results. ⑩ Individuals who have received a live or live-attenuated vaccine within 28 days before administration of the investigational product or who plan to receive such a vaccine during the study. ⑪ Women who are pregnant, breastfeeding, or planning to become pregnant at screening. ⑫ Individuals who have participated in a clinical trial involving a radiopharmaceutical within 1 month before screening. ⑬ Individuals who have received medications or undergone clinical procedures within 1 month before screening that, in the investigator's judgment, may affect the uptake of \[⁶⁸Ga\]Ga-EP ⑭ Individuals with any other condition that, in the investigator's judgment, makes them unsuitable for study participation.