HEC169096 in Participants With Advanced Solid Tumors

Inclusion Criteria: * Phase 1：Pathologically documented, definitively diagnosed non-resectable advanced solid tumor. * Phase 2： All participants must have an oncogenic RET-rearrangement/fusion or mutation (excluding synonymous, frameshift, and nonsense mutations) solid tumor. * Participants has Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0-2. * Measurable or non-measurable disease as determined by RECIST 1.1; * Adequate hematologic, hepatic and renal function; * Life expectancy of at least 12 weeks; * Negative pregnancy test (urine or serum) for female patients of childbearing potential; * Participants agrees to provide tumor tissue (archived, if available or a fresh biopsy). Exclusion Criteria: * Participant's cancer has a known primary driver alteration other than RET. * Nitrosourea, anthracyclines and mitomycin chemotherapy within 6 weeks prior to study treatment; * Chemotherapy, immunotherapy, radiotherapy, or major surgery within 4 weeks or 5 half-lives (whichever is longer) prior to study treatment; * Those who have received more than 30% of bone marrow radiation or wide-range radiotherapy within 4 weeks before the first study drug treatment (the patients receiving palliative radiotherapy are within 2 weeks before receiving study drug treatment); * Had received traditional Chinese medicine for anti-tumor within a week before receiving study drug treatment; * Had received live vaccine within 4 weeks prior to study treatment; * Had received any investigational agent from other clinical study within 4 weeks or 5 half-lives (whichever is longer) prior to study treatment or are currently participating in other clinical trials; * Any unresolved toxicities from prior therapy greater than Common Terminology Criteria for Adverse Events (CTCAE) Grade 1 at the time of starting study treatment . * Central nervous system (CNS) metastases or a primary CNS tumor that is associated with progressive neurological symptoms. * Patients with other malignant tumors within 5 years before the first use of drugs * Patients have a history of severe cardiovascular disease; * Active hepatitis (Hepatitis B: HBsAg-positive and HBV-DNA ≥ 2000 IU/ mL or ≥ 10\^4 cps/ mL; Hepatitis B: HCV antibody-positive and HCV-RNA positive), HIV antibody-positive. * Patients with clinically active interstitial lung disease, active pneumonia, and radiation pneumonia requiring treatment; * Poorly controlled pleural effusion, abdominal effusion, or pericardial effusion after intervention (such as drainage); * Clinically significant active malabsorption syndrome or other diseases that may affect study drug administration and gastrointestinal absorption; * Patients have been treated with any strong CYP3A inhibitors or inducers within 2 weeks prior to the first dose or PPIs in the first week before the first dose.