Futuoning Fovinaciclib Citrate Capsules

1. Indications and Usage
Fovinaciclib citrate capsules are indicated in combination with an aromatase inhibitor for the initial endocrine-based treatment, or in combination with fulvestrant for disease progression after endocrine therapy, for adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative locally advanced or metastatic breast cancer.
2. Dosage and Administration
Recommended Dosage: The recommended dosage is 200 mg taken orally once daily.
Administration: Administer continuously for 21 days followed by 7 days of rest per cycle (28-day cycle). The capsules may be taken with or without food. They must be swallowed whole and not crushed or chewed.
Missed Dose: If a dose is missed, it should be taken as soon as possible on the same day or subsequent days. However, do not make up the dose if the next scheduled dose is less than 8 hours away.
Dose Modifications: Dose reductions should be managed in descending order (200 mg to 150 mg to 100 mg) or interruptions may be required based on the severity of adverse reactions.
3. Mechanism of Action
Fovinaciclib is a highly selective, small-molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6). It inhibits the phosphorylation of the retinoblastoma (Rb) protein, thereby arresting the cell cycle at the G1 phase and inhibiting tumor cell proliferation.
4. Safety and Warnings
Neutropenia: Neutropenia and leukopenia are very common adverse reactions. Complete blood counts must be monitored regularly, especially during the first few weeks of treatment.
Hepatotoxicity: Elevations in hepatic enzymes (ALT, AST) and bilirubin can occur. Liver function tests should be monitored regularly.
Embryo-fetal Toxicity: Based on its mechanism, this drug can cause fetal harm. Patients should be advised to use effective contraception during treatment.
QT Prolongation: Fovinaciclib can cause QT prolongation. ECG monitoring is recommended in patients with a history of cardiac disease or those taking other drugs known to prolong the QT interval.
5. Adverse Reactions and Clinical Research
Common Adverse Reactions: The most common adverse reactions include neutrophil count decreased, leukocyte count decreased, anemia, thrombocytopenia, elevated ALT, elevated AST, and hypertriglyceridemia.
Clinical Research: Efficacy and safety were established in pivotal Phase 3 clinical trials (FCN-437c-III201 and FCN-437c-III202), which demonstrated significant improvements in progression-free survival compared to placebo when combined with endocrine therapy.
6. Drug Interactions
CYP3A4 Inhibitors: Strong CYP3A4 inhibitors may increase fovinaciclib exposure. Co-administration should be avoided; if unavoidable, reduce the dose to 100 mg once daily.
CYP3A4 Inducers: Strong CYP3A4 inducers may decrease fovinaciclib exposure and should be avoided.
Drugs Prolonging QTc: Concomitant use with drugs known to prolong the QTc interval should be approached with caution.
7. Pharmaceutical Information
Composition: The active ingredient is fovinaciclib citrate.
Appearance: Opaque hard capsules, available in 25 mg and 100 mg strengths.
Storage: Store in the original packaging at controlled room temperature, protected from moisture.