A Study to Evaluate the Efficacy and Safety of TSL-1502 Capsules in Breast Cancer Patients With Germline BRCA Mutations

Inclusion Criteria:

• 1. Agree to follow the clinical trial protocol, volunteer, and sign the informedconsent form (ICF).

2. Women aged ≥ 18 years and ≤ 75 years at the date of signing the ICF. 3)HER2-locally advanced breast cancer diagnosed by histopathology and/or cytology (Unable to receive radical therapy) or metastatic breast cancer, and previouschemotherapeutic line of cytotoxicity for locally advanced or metastatic breast cancerwas ≤ 3.
3. Prior platinum therapy is allowed, but the best response to platinum therapy isrequired to be CR, PR, or persistent ≥ 12 weeks SD. If given as neoadjuvant/adjuvanttherapy, the time from the last dose of platinum to relapse is ≥ 6 months.
4. Hormone receptor-positive patients need to have received at least first-line ofendocrine therapy for locally advanced or metastatic breast cancer but failed, orunsuitable for endocrine therapy in the judgment of the investigator.
5. In neoadjuvant, adjuvant and/or metastatic stages, the patients who have receivedantitumor therapy with Taxane ± Anthracycline.
6. Failure of front-line therapy (disease progression or toxicity intolerance), andthe investigator judged that it was suitable to receive the systemic monotherapy (including capecitabine tablets, vinorelbine tartrate injection, eribulin mesylateinjection).
7. Tested or reviewed by a third-party central laboratory to determine whether thereis harmful or suspected harmful gBBRCAm in the blood.
8. At least one measurable (non-lymph node longest diameter ≥ 10 mm, lymph nodes witha minimum diameter of ≥ 15 mm, according to RECIST version 1.1 criteria) of targetlesions. Note: Previously irradiated lesions cannot be used as targets lesions unlessthere is significant progression of the lesion.
9. The physical condition score is 0-1 according to the scale of The EasternCooperative Oncology Group (ECOG).
10. Expected survival ≥ 12 weeks. 12) Meet the following criteria (The use of anyblood components and cell growth factors is not permitted within 2 weeks prior toinitial administration): Bone marrow function: absolute neutrophil count (ANC) ≥ 1.5 × 109/L (1500/mm3); platelets ≥ 100 × 109/L (1 × 105/mm3); Hemoglobin ≥ 90 g/L; Liverfunction: serum bilirubin ≤ 1.5 × upper limit of normal (ULN), but except forGilbert's syndrome patients (persistent or recurrent hyperbilirubinemia, unboundbilirubin elevation is present in the absence of evidence of hemolysis or liverpathology); patients without liver metastasis, alanine aminotransferase (ALT) andaspartate aminotransferase (AST) ≤ 2.5×ULN; ALT and AST ≤ 5×ULN for patients withliver metastasis; Renal function: serum creatinine ≤ 1.5 × ULN, or creatinineclearance (Ccr) ≥ 50 mL/min (Calculated according to the Cockcroft-Gault formula);Cockcroft-Gault formula: female Ccr (mL/min) = 0.85 × weight (kg) × (140-age)/ [72 ×creatinine (mg/dL)] Coagulation function: international normalized ratio (INR) ≤ 1.5 ×ULN, activated partial thromboplastin time (APTT) ≤ 1.5 × ULN.
11. Women of childbearing age are willing to take effective contraception from signingthe ICF to 6 months after the last administration of the investigational drug. Womenof childbearing age must have a negative blood pregnancy test result 7 days before thefirst dose.

Exclusion Criteria:

• 1. Pregnant or lactating women. 2) Active inflammatory breast cancer. 3) Previoustreatment with other PARP inhibitor drugs, including but not limited to TSL-1502,Olaparib, Talazoparil, Fluzoparil, Nilaparib, Rucaparib, Veliparib, etc. 4) Known tobe allergic to TSL-1502 or any excipient of TSL-1502 capsules. 5) Known to have activebrain metastases (defined as meeting any of the following: stable neurological imaging < 4 weeks; symptoms related to brain metastasis; steroid therapy required;leptomeningeal disease); patients must have completed any prior treatment for brainmetastases ≥ 4 weeks prior to the first dose.

6. Patients with previous or current another malignancy. 7) Have other serious oruncontrollable clinical diseases or past medical history, surgical history, includingbut not limited to hepatic/renal dysfunction, respiratory disorders, endocrinedisorders, metabolic disorders, neuropathy, or mental disorders, organtransplantation, etc.
7. Gastrointestinal or digestive system diseases that may affect the absorption ofinvestigational products as judged by the investigator or past medical history, suchas intractable hiccups, nausea, vomiting, chronic gastrointestinal disease (e.g. Ron'sdisease, ulcerative colitis, active gastric ulcer, etc.), dysphagia, etc.
8. Have serious cardiovascular system disease or past medical history (meet any of thefollowing conditions); Definite cardiovascular abnormality within 6 months prior tofirst dose (e.g., myocardial infarction, cardiac arrhythmia, angina pectoris,angioplasty, vascular stent implantation, coronary artery bypass surgery, congestiveheart failure, etc.); Baseline electrocardiogram QT or Fridericia-corrected QTinterval (QTcF) prolongation [QTcF = QT/(RR 0.33), QTcF > 480 ms]; Left ventricularejection fraction < 50% by cardiac ultrasound; Uncontrolled hypertension (Patientswith blood pressure ≥150/100 mmHg after lifestyle improvement and medication) 10)Participated in clinical trials of other drugs or medical devices within 4 weeks priorto initial administration (note: except for those who did not use investigationaldrugs or medical devices).
9. Patients who underwent major surgery or significant traumatic injury within 4weeks prior to initial administration, or who planned to undergo major surgery in thetrial period.
10. Chemotherapy, radiotherapy, non-hormone targeted therapy, endocrine therapy,Anti-neoplastic immunotherapy [physiologic replacement doses of corticosteroidspermitted (prednisone or equivalent < 15 mg/day)], Chinese medicine therapy with aclear indication for the treatment of breast cancer, or other anti-tumor therapy werereceived within 4 weeks prior to initial administration.
11. AEs related to previous surgery and previous anti-tumor therapy (CTCAE version 5.0) did not recover to ≤ 1 grade (alopecia, pigmentation, platinum-inducedneurotoxicity grade 2 and lower, except for clinically significant or asymptomaticlaboratory abnormalities).
12. Patients who had received a CYP2D6 liver enzyme inhibitors or inducers within 2weeks prior to initial dosing, or who cannot discontinue the use of CYP2D6 liverenzyme inhibitors or inducers during the trial.
13. Patients who test positive for treponema pallidum antibody, human immunodeficiencyvirus (HIV) antibody, hepatitis C virus (HCV) RNA, or active hepatitis B patients [defined as hepatitis B virus (HBV) DNA ≥ ULN].
14. The investigator considered that patients have other conditions that might affectcompliance or are not suitable for participating in this trial.