This study is a multicenter, open-label, multi-cohort phase II clinical trials to evaluate the efficacy and safety of TQB3616 capsules combined with Fulvestrant injection in subjects with HR-positive and HER2-negative advanced and/or metastatic breast cancer, including Cohort 1 and Cohort 2. Each cohort will enroll 30-60 cases.

Inclusion Criteria:

• 1.Understood and signed an informed consent form. 2.Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1; Life expectancy ≥ 3 months. 3. Histopathologically confirmed HR positive and HER2 negative advanced or metastatic breast cancer. 4.Cohort 1: patients had received ≤1 line of treatment. 5.Cohort 2: patients had not previously received systemic antitumor therapy. 6.Has at least one measurable lesion according to RECIST1.1 criteria. 7.Adequate laboratory indicators.

Exclusion Criteria:

• 1. Concomitant disease and medical history:

  1. Has other malignant tumors within 3 years;
  2. Has multiple factors affecting oral medication;
  3. Unalleviated toxicity ≥ grade 1 due to any previous anticancer therapy;
  4. Has active or uncontrolled severe infections before the first dose;
  5. Cirrhosis, active hepatitis#
  6. Have a history of immunodeficiency; 2. Tumor-related symptoms and treatment:

  1. Has central nervous system metastases (CNS) and/or cancerous meningitis or leptomeningeal carcinomatosis;

  2. Had received chemotherapy within 3 weeks prior to the first dose, and had received radiotherapy , hormone therapy, or other anti-tumor therapy within 2 weeks prior to the first dose;

  3. Has uncontrollable pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures.

     3. Has known to be allergic to Fulvestrant injection , TQB3616 or any excipient.

     4. Has Participated in other clinical trials within 4 weeks before first dose. 5. According to the judgement of the investigators, there are other factors that may lead to the termination of the study.