Safety and Activity of HF50 in Patients With Advanced Solid Tumors

A study to assess the safety, tolerability, and pharmacokinetics of HF50 in participants with advanced solid tumors.

Inclusion Criteria: * Voluntary participation: Capable of giving signed informed consent and able to comply with all study-related procedures. * Age: Adults \>= 18 years of age at the time of signing informed consent; male or female. * Disease Status: Participants with histologically or cytologically confirmed advanced solid tumors that are unresectable or metastatic, who have failed or are intolerant to standard therapies, or for whom no effective therapy currently exists. Examples include HER2-expressing gynecological tumors and recurrent ovarian clear cell carcinoma after failure of platinum-based chemotherapy. * Performance Status: Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 1. * Life Expectancy: Anticipated survival of no less than 6 months. * Measurable Disease: At least one measurable lesion according to RECIST v1.1 definitions. * Organ and Bone Marrow Function: Bone Marrow Reserve: Absolute neutrophil count (ANC) \>= 1.5 x 10\^9/L, lymphocyte count \>= 1.0 x 10\^9/L, platelet count \>= 90 x 10\^9/L, and hemoglobin \>= 9.0 g/dL (no blood transfusion or hematopoietic stimulators within 14 days). Coagulation Function: Activated partial thromboplastin time (APTT) \ 100 mmHg). * Infection: Active infection or unexplained fever \> 38.5 degrees C within 1 week prior to the first dose (tumor-related fever is permitted per investigator judgment). * Viral Infection: HIV infection, active HBV (HBV DNA \> ULN), or active HCV (HCV RNA \> ULN). * Gastrointestinal Symptoms: Significant digestive system symptoms or other factors requiring intervention within 4 weeks prior to the first dose. * Pregnancy/Lactation: Female participants who are pregnant or breastfeeding. * Other: Any other serious systemic disease or reason that, in the investigator's opinion, makes the participant unsuitable for the study.