Chidamide Combined With Zimberelimab in the Treatment of Metastatic Triple-negative Breast Cancer Patients

The proportion of patients with measurable tumor size reduction of a predefined amount (complete response [CR], partial response [PR]) according to the response evaluation criteria in solid tumors (RECIST) version 1.1. Complete Response: Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to <10 mm (<1 cm). Partial Response: At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.

The proportion of patients with measurable tumor size stable lasting ≥24 weeks (stable disease [SD]) or its size reduction of a predefined amount (complete response [CR], partial response [PR]) following the response evaluation criteria in solid tumors (RECIST) version 1.1. Complete Response (CR) and Partial Response (PR) are defined in Primary Outcome Measure. Stable Disease: Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD (progressive disease), taking as reference the smallest sum diameters while on study. Progressive Disease: At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm (0.5 cm). (Note: the appearance of one or more new lesions is also considered progression).

The interval time from the date of initiation treatment for metastatic breast cancer to the date of the first documented disease progression or death due to any cause.

The interval time from the date of initiation treatment for metastatic breast cancer to the date of death from any cause.

Occurrence and severity of AEs by NCI-CTCAE v5. Changes in laboratory parameters (hematology and serum chemistry), vital signs and ECG parameters. Grade 3 or 4 abnormalities in serum chemistry laboratory parameters.

Baseline tumor biopsy from metastatic or recurrent lesions was required, we analyze and compare the difference of tumor immune microenvironment among patients with different responses to this intervention via the single cell sequencing of acquired tumor biopsy.

And peripheral blood samples were collected at baseline, one day before the second cycle treatment and the date of withdrawal from this clinical trial confirmed by researchers. Then peripheral blood mononuclear cell cluster analysis will be performed and compared their changes before and after treatment.