Osimertinib Instructions for Use

Indications:

Applicable to the initial treatment of patients with locally advanced or metastatic non-small cell lung cancer who have EGFRexon19 deletion or exon 21 (L858R) substitution mutation.

Osimertinib can be used as a second-line treatment for patients with locally advanced or metastatic non-small cell lung cancer who have previously received EGFRtyrosine kinase inhibitors (TKI) and have disease progression during or after treatment, and whose EGFR T790M mutation-positive patients have been confirmed by testing.

Mechanism of action:

Osimertinib is a clinical drug for the treatment of lung cancer. It blocks signaling pathways by inhibiting EGFR tyrosine kinase activity and inhibits tumor growth and metastasis. Mainly by inhibiting the tyrosine kinase activity of the epidermal growth factor receptor (EGFR), thereby blocking the conduction of the EGFR signaling pathway, inhibiting the proliferation, differentiation and growth of tumor cells, inducing tumor cell apoptosis, and reducing their spread to surrounding tissues and organs. Osimertinib is more selective for mutant EGFR than wild-type EGFR. While inhibiting the growth of tumor cells, it has relatively little toxicity to normal cells, thereby reducing treatment-related adverse reactions.

Medication method:

The recommended dose is 80 mg daily until disease progression or intolerable toxicity occurs. If dose reduction is necessary, the dose should be reduced to 40mg once a day times. The specific dosage adjustment plan should be based on medical advice.

Side effects:

Skin reactions: Osimertinib may cause rash, dry skin, itching, hand-foot syndrome, etc. These reactions are usually common, but most are mild and may lessen over time.

Digestive system abnormalities: including nausea, vomiting, diarrhea, loss of appetite, etc. These symptoms may affect patients' nutrient absorption and quality of life.

Abnormal liver function: A small number of patients may have abnormal liver function, manifested as elevated levels of ALT, AST, etc. Treatment recommendations include regular monitoring of liver function indicators. If there are any abnormalities, the doctor should be informed promptly. If necessary, the dose of osimertinib should be reduced or treatment should be suspended.

Respiratory problems: Interstitial lung disease and pneumonia are common complications with osimertinib. These reactions can be serious and even life-threatening. Treatment recommendations include regular monitoring of pulmonary symptoms and seeking medical attention promptly if symptoms such as difficulty breathing or coughing occur. If interstitial lung disease is diagnosed, osimertinib should be permanently discontinued and necessary treatment measures should be taken.

Cardiovascular system abnormalities: Osimertinib may cause cardiac arrhythmias, reduced cardiac ejection fraction, heart failure, and myocarditis. Treatment suggestions include regular monitoring of electrocardiogram and cardiac function indicators. If there are any abnormalities, the doctor should be informed promptly and corresponding treatment measures should be taken if necessary.

Warnings and precautions:

Before and during the use of osimertinib, liver function should be monitored regularly, including serum aminotransferase, total bilirubin and other indicators. Osimertinib may cause electrolyte abnormalities, especially in those at risk for heart disease. Therefore, electrolyte levels should be monitored regularly. Osimertinib may cause bone marrow suppression, resulting in low blood cell counts. Patients should undergo regular hematology tests and any abnormalities should be dealt with promptly.

Drug interactions:

CYP3A4Inhibitor/Inducer: Osimertinib is mainly metabolized by CYP3A4 enzyme, and CYP3A4strong inhibitors (such as itraconazole) may increase its exposure and increase the risk of adverse reactions; the combined use of CYP3A4strong inducers (such as rifampicin) may reduce its exposure and affect the efficacy.

Transporter substrates: Osimertinib inhibits the BCRP and P-gp transporters, and coadministration with these transporter substrates (such as digoxin, dabigatran) may affect drug exposure.

Medication for special populations:

Osimertinib may cause harm to the fetus and should be avoided by pregnant women. Breastfeeding women should stop breastfeeding while taking osimertinib.