Kisqali is a CDK4/6 inhibitor, which is mainly used for the treatment of specific breast cancer. When using Kisqali, attention should be paid to cardiovascular monitoring, drug use in special populations, drug interactions and other matters. The following provides a detailed explanation from two aspects: indications and precautions.

1 Indications

(1) Advanced or metastatic breast cancer with hormone receptor positive (HR+) and human epidermal growth factor receptor negative (HER2-), combined with aromatase inhibitor, is used as the initial endocrine therapy.

(2) Used in combination with Fluvistran for postmenopausal female patients who have failed previous endocrine therapy.

2 Medication precautions

2.1 Cardiovascular Monitoring

(1) Before treatment, an electrocardiogram and electrolyte assessment are required. QTcF>450ms (male) or>470ms (female) is contraindicated.

(2) Regular monitoring of electrocardiogram during treatment, especially for those with electrolyte imbalance or using drugs to prolong QT interval.

2.2 Special populations

(1) Pregnancy: It has embryonic toxicity, and effective contraception is required during treatment and 3 weeks after discontinuation of medication.

(2) Breastfeeding period: Medication may be secreted into breast milk, and breastfeeding should be stopped during the treatment period and 3 weeks after the last administration.

(3) Liver dysfunction: Child Pugh grade C is contraindicated, grade B requires reduction.

2.3 Drug Interactions

(1) Avoiding the use of potent CYP3A4 inhibitors (such as ketoconazole) in combination may significantly increase blood drug concentrations.

(2) CYP3A4 inducers (such as rifampicin) may reduce efficacy and require dosage adjustment.

2.4 Other precautions

(1) Neutropenia: Monitor blood routine before treatment and every cycle, and discontinue medication if grade 3-4 occurs.

(2) Elevated liver enzymes: Regularly monitor liver function and suspend medication when ALT/AST>3 times ULN.