Abiraterone With Dalpiciclib in Salivary Gland Carcinoma

Inclusion Criteria: * \- Aged 18-75 years, male or female; * Patients with histopathologically confirmed salivary gland malignancy of the head and neck: recurrent/metastatic disease without curative-intent therapeutic options (surgery/radiotherapy), or unresectable locally-advanced disease, with at least one measurable lesion (≥10 mm on spiral CT, complying with RECIST version 1.1); * HER-2-negative and AR-positive status determined by immunohistochemistry (IHC); * Availability of evaluable tumor tissue (paraffin-embedded specimen obtained within the past 2 years or fresh tumor tissue); * ECOG performance status of 0 or 1; * Expected survival ≥12 weeks; * Adequate major-organ function within 2 weeks prior to study treatment initiation, meeting the following criteria: * Bone marrow: haemoglobin ≥100 g/L, white blood cell count ≥4.0 × 10⁹/L or absolute neutrophil count ≥2.0 × 10⁹/L, platelet count ≥100 × 10⁹/L, in the absence of transfusion or colony-stimulating factor support; * Liver: total serum bilirubin ≤1.5 × upper limit of normal (ULN); aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤1.5 × ULN; * Kidney: serum creatinine ≤1.5 × ULN OR creatinine clearance ≥60 mL/min; blood urea nitrogen ≤200 mg/L; * Urine protein: negative; if urine protein is 1+, 24-hour total urinary protein must be \<500 mg; * Glucose: within normal range; or patients with diabetes with stable glycaemic control under ongoing management; * Cardiac function: no myocardial infarction within 1 year; no unstable angina; no symptomatic severe arrhythmia; no cardiac insufficiency; * For women of child-bearing potential: negative serum pregnancy test within 7 days before the first dose of study drug. Men with reproductive potential and women at risk of pregnancy must use highly-effective contraceptive measures throughout the study (e.g., oral contraceptives, intrauterine device, sexual abstinence, or barrier contraception combined with spermicide), and continue contraception for 12 months after treatment completion; * Subjects voluntarily participate in this study, provide written informed consent, demonstrate good compliance, and are willing to complete follow-up assessments; * Patients for whom the investigator judges treatment may confer clinical benefit. Exclusion Criteria: * \- Patients with prior exposure to anti-androgen therapy or CDK4/6 inhibitors. * Patients receiving ongoing anti-neoplastic treatment. * Patients who have participated in, or are participating in, another investigational drug/therapy clinical trial within 4 weeks prior to the first dose of study drug. * Patients who received haematopoietic stimulating factors, such as granulocyte-colony-stimulating factor (G-CSF) or erythropoietin, within 1 week before the first administration of study drug. * Positive serology for human immunodeficiency virus (HIV) antibody or \*Treponema pallidum\* antibody. * Patients with active hepatitis B or hepatitis C: * HBsAg-positive or HBcAb-positive subjects with detectable HBV DNA (value above the upper limit of normal); * Subjects with positive HCV antibody and detectable HCV RNA (value above the upper limit of normal). * Symptomatic and clinically significant pleural effusion or ascites requiring therapeutic intervention. * Active pulmonary disease (interstitial pneumonia, pneumonitis, obstructive pulmonary disease, asthma) or history of active pulmonary tuberculosis. * Presence of any uncontrolled clinical conditions, including but not limited to: * Persistent or active (severe) infection; * Poorly-controlled diabetes mellitus; * Cardiac disease (New York Heart Association (NYHA) class III/IV congestive heart failure or cardiac conduction block). * Occurrence of any of the following events within 6 months prior to first-dose administration: deep-vein thrombosis or pulmonary embolism; myocardial infarction; severe or unstable arrhythmia or angina pectoris; percutaneous coronary intervention, acute coronary syndrome, coronary artery bypass grafting; cerebrovascular accident, transient ischaemic attack, cerebral embolism. * Prior history of stem-cell transplantation or solid-organ transplantation. * History of substance abuse of psychotropic agents without successful abstinence, or history of psychiatric disorders. * Other severe, acute or chronic medical conditions or laboratory abnormalities which, in the investigator's judgement, may increase risks associated with study participation or confound the interpretation of study results. * Patients deemed by the investigator to have poor compliance, or with other conditions rendering them unsuitable for trial participation. * Patients with a history of another malignancy within the past five years.