Capivasertib, when used in combination with fulvestrant, 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.

What Are the Side Effects of Capivasertib?

Gastrointestinal Reactions

Diarrhea (incidence rate: 72%).

Nausea (35%).

Vomiting (21%).

Stomatitis (20%).

Abnormal Laboratory Test Results

Elevated random blood glucose (57%).

Lymphopenia (47%).

Decreased hemoglobin (45%).

Elevated fasting blood glucose (37%).

Leukopenia (32%).

Elevated triglycerides (27%).

Severe Side Effects of Capivasertib That Require Vigilance

Hyperglycemia

Clinical manifestations: Severe hyperglycemia may be accompanied by ketoacidosis.

Symptoms include: Extreme thirst, increased frequency of urination and urine output, increased appetite with weight loss.

Management measures: Evaluate fasting glucose (FG) and glycated hemoglobin (HbA1c) before starting treatment.

Monitor blood glucose regularly during treatment (at least once every 2 weeks for the first 2 weeks, and once a month starting from the 2nd month).

Temporarily suspend, reduce the dose, or permanently discontinue the drug based on the severity.

Consider the use of oral hypoglycemic agents (29% of patients use metformin, 15% use insulin).

Severe Diarrhea

Patients are advised to increase oral fluid intake.

Initiate antidiarrheal treatment immediately when diarrhea symptoms appear.

Temporarily suspend, reduce the dose, or permanently discontinue the drug based on the severity.

Cutaneous Adverse Reactions

Monitor cutaneous symptoms.

Early consultation with a dermatologist is recommended.

Temporarily suspend, reduce the dose, or permanently discontinue the drug based on the severity.

Embryo-Fetal Toxicity

Animal studies have shown that capivasertib can cause embryo-fetal death and reduced fetal weight.

Women of childbearing age should use effective contraceptive measures during treatment and within 1 month after the last dose.

Male patients with female partners of childbearing age should use effective contraceptive measures during treatment and within 4 months after the last dose.

Precautions for Capivasertib Administration

Administration Method

Swallow the tablet whole; do not chew, crush, or split it.

If a dose is missed and the time elapsed since the scheduled dose is within 4 hours, the missed dose can be taken. If more than 4 hours have passed, skip the missed dose.

If vomiting occurs after taking the drug, do not take an additional dose; take the next dose as scheduled.

Drug Interactions

Strong CYP3A inhibitors: Concomitant use should be avoided as much as possible; if unavoidable, reduce the dose of capivasertib to 320 mg twice daily.

Moderate CYP3A inhibitors: Reduce the dose of capivasertib to 320 mg twice daily.

Strong and moderate CYP3A inducers: Concomitant use should be avoided.