A Phase I/II Study of XZP-3287 in Metastasis Solid Tumors

Inclusion Criteria:

• Single agent and combination dose exploration study：Patient is an adult male/female 18~70 years old; the phase II study：Patient is an adult male/female ≥ 18 years old;

• Single agent dose escalation study ：Patients with a histologically or cytologicallyconfirmed diagnosis of a solid tumor for which Standard treatment failure or nofurther effective standard treatment is available.

Combination dose exploration study：Patients with locally advanced or metastatic breast cancer with hormone receptor positive (HR+) and her2-negative (HER2-) were not eligible for surgical resection or radiotherapy for the purpose of cure, and had no clinical indications for chemotherapy, and received endocrine therapy ≤1 line.

The phase II study: Locally advanced or metastatic breast cancer diagnosed histologically or cytologically not suitable for surgery or radical radiotherapy; HR+ and HER2- ; have locally advanced disease not amenable to curative treatment by surgery or metastatic disease; progress after previous endocrine therapy; at least 1 chemotherapy regimen in the previous adjuvant or metastasis contains paclitaxel; there should be at least 2 prior chemotherapy regimens;

• At least one measurable lesion (based on RECIST v1.1);

• Patient has an Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1;

• Have recovered from the acute effects of therapy (until the toxicity resolves toeither baseline or Grade 1) except for residual alopecia;

• Adequate organ and marrow function;

• The life expectancy of the patient was determined by the investigator to be ≥12weeks;

• Fertile male or female patients must agree to use an effective contraceptive methodduring the study period and for three months after the last study medication;

• Patient has signed informed consent before any trial related activities.

Exclusion Criteria:

• Single agent and combination dose exploration study：Patients with known uncontrolledor symptomatic CNS metastases; The phase II study：Have central nervous system (CNS)metastasis, or Have visceral crisis, or Inflammatory breast cancer.

• Have received an autologous or allogeneic stem-cell transplant.

• Patient has impairment of gastrointestinal (GI) function or GI disease.

• Single agent and combination dose exploration study：Any other malignancy wasdiagnosed within 3 years prior to enrollment, except for basal cell carcinoma,squamous cell carcinoma, or carcinoma in situ of the cervix, which is adequatelytreated and the disease is stable.

The phase II study：Have a history of any other cancer (except nonmelanoma skin cancer or carcinoma in-situ of the cervix), unless in complete remission with no therapy for a minimum of 3 years.

• Subject has impaired cardiac function or heart disease of clinical significance.

• Cerebrovascular accidents within 6 months before enrollment, including a history oftransient ischemic attack or stroke.

• Major surgery or surgical treatment due to any cause occurred within 4 weeks priorto enrollment.

• Presence of any serious and/or uncontrolled disease in the opinion of theinvestigator that may interfere with the study assessment.

• Uncontrollable pleural effusion, peritoneal effusion, pericardial effusion in the 4weeks before the first administration (except for a small amount of effusiondetected by imaging examination).

• A prior history of definite neurological or psychiatric disorders, includingepilepsy or dementia.

• Chronic active HBV, HCV or HIV diseases.

• Patient who received any CDK4/6 inhibitor or patients who plan surgery, or theinvestigator determines that surgery or radical radiation therapy is required.

• Participation in a prior treatment of chemotherapy, radiotherapy, endocrinotherapy,targeted therapy, immunotherapy and any investigational study within 14 days priorto enrollment.

• Bone marrow suppression therapy, such as GCS-F, EPO, or blood transfusion, wasadministered within 14 days prior to enrollment.

• Patient with a known hypersensitivity to any of the excipients in this study.

• Pregnant or breastfeeding.

• The researchers considered that there were some cases that were not suitable forinclusion.