A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Preliminary Antitumor Activity of INV-6452 in Adult Patients With Hormone Receptor Positive, Human Epidermal Growth Factor Receptor 2 Negative (HR+/HER2-) Advanced/Metastatic Breast Cancer or Locally Advanced/Metastatic Solid Tumor

Prior treatment

• Patients with primary CNS tumors or CNS metastases with prior local treatment failure.
• Have received any anti-tumor therapy or participated in other therapeutic clinical trial within 28 days prior to the first dose of study drug.
• Has undergone major surgery within 28 days prior to the first dose of study drug.
• Prior anti-tumor therapy-related toxicities have not recovered to protocol-specified grades.
• Diagnosed with immunodeficiency or received any form of immunosuppressive therapy within 7 days prior to the first dose.
• Have any medical conditions likely to impair digestion and absorption of the investigational product.
• Have experienced a severe concurrent infection 14 days prior to the first dose of study drug.
• Are currently receiving any other investigation agent.
• Have received prior CDK2 inhibitors.

Other illness

• Have a second primary malignancy.
• Patients with other severe and persistent underlying medical conditions as assessed by the Investigator.
• Have protocol-defined clinically significant cardiovascular diseases.
• Confirmed infection with HIV, HBV or HCV.
• Patients with known hypersensitivity to the study drug or any of its components.
• History of allogenic tissue or solid organ transplant.
• Has other severe systemic diseases or for other reasons deemed ineligible for participation in this clinical trial by the investigator.

Lab values

• Patients with poorly managed blood glucose levels and blood pressure.
• Clinically significant abnormal serum potassium or sodium as judged by the investigator.

Other

• Prolonged QTcF interval.
• Are unwilling or unable to comply with procedures required in this protocol.

• Written informed consent obtained.
• Adult patients aged ≥ 18 years.
• Patients with histologically or cytologically confirmed unresectable locally advanced or metastatic solid tumors, who have disease progression following standard-of-care therapy, are intolerant to standard treatment, or have no available standard treatment options (e.g., HR+/HER2- breast cancer, Cyclin E1-overexpressing solid tumors and other solid tumors).
• Agree to provide available archived FFPE tumor tissue specimens or voluntarily accept pre-treatment tumor biopsy (Phase Ⅱ).
• Have RECIST 1.1-defined measurable lesions.
• Has a life expectancy of \> 3 months.
• ECOG performance status 0-1.
• Adequate marrow, liver and kidney function.
• Meet the study's specified contraceptive requirements.