Capivasertib is a kinase inhibitor that received its first approval for marketing in the United States in 2023. When used in combination with fulvestrant, this medication is indicated for the treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer.

Precautions for Capivasertib Administration

Patient Selection Criteria

Capivasertib is only applicable to patients in whom PIK3CA, AKT1, or PTEN gene mutations in tumor tissue have been confirmed by an FDA-approved detection method.

The presence of these biomarkers must be confirmed through genetic testing before the medication is used.

Contraindications

Patients with a severe allergic reaction to capivasertib or any of its components are prohibited from using this medication.

A detailed allergic history of the patient should be obtained before initiating treatment.

Medication in Special Populations

Capivasertib is contraindicated in pregnant women, as it may cause harm to the fetus.

Women of childbearing age should use effective contraceptive measures during treatment and for 1 month after discontinuing the medication.

Male patients whose female partners have childbearing plans should use effective contraceptive measures during treatment and for 4 months after discontinuing the medication.

Lactating women should discontinue breastfeeding.

Dose Adjustment

Depending on the severity of adverse reactions, temporary drug withdrawal, dose reduction, or permanent drug discontinuation may be required.

The first dose reduction can be adjusted to 320 mg twice daily, and the second dose reduction can be lowered to 200 mg twice daily.

If the medication is still not tolerable after the second dose reduction, permanent discontinuation should be implemented.

Administration Precautions

The tablets should be swallowed whole and must not be chewed, crushed, or split.

If vomiting occurs within 4 hours after taking the medication, the missed dose should not be made up; instead, the next dose should be taken at the originally scheduled time.

If the time since the missed dose exceeds 4 hours, the missed dose should be skipped, and the next dose should be taken as planned.

Medication Monitoring for Capivasertib

Blood Glucose Monitoring

Hyperglycemia is a common adverse reaction of capivasertib, with an incidence rate of approximately 18%, and severe cases may lead to ketoacidosis.

Fasting blood glucose and glycated hemoglobin (HbA1c) should be measured before starting the medication, and regular monitoring should be conducted during treatment.

Fasting blood glucose should be measured at least once every two weeks in the first month of treatment.

Starting from the second month, fasting blood glucose should be measured at least once a month.

Glycated hemoglobin should be measured once every three months.

For patients with a history of diabetes or high-risk factors (such as obesity, baseline blood glucose > 160 mg/dL, etc.), the frequency of monitoring should be increased.

Patients should be informed about the symptoms of hyperglycemia (such as extreme thirst, frequent urination, increased appetite accompanied by weight loss, etc.) and should seek medical attention immediately if these symptoms occur.

Diarrhea Monitoring

Approximately 72% of patients will experience diarrhea, among which 9% have grade 3-4 severe diarrhea.

Increase fluid intake when diarrhea symptoms occur.

Have antidiarrheal medications available for timely use.

Record the frequency and severity of diarrhea.

Seek medical attention promptly for severe or persistent diarrhea.