Osimertinib: indications, mechanism of action, usage and dosage, side effects, contraindications, etc.

Osimertinib is a drug used to treat non-small cell lung cancer. It applies to the following situations:

1.For adjuvant treatment of EGFRadult patients with 19 exon deletion or 21 exon L858R mutation after lung cancer surgery.

2.As first-line treatment for metastatic non-small cell lung cancer in adult patients with EGFRexon19 deletion or exon21 L858R mutation.

3.Combination of pemetrexed and platinum-based chemotherapy for patients with EGFRexon19deletion or exon21 For first-line treatment of adult patients with L858Rmutated locally advanced or metastatic non-small cell lung cancer, an FDAapproved test is required.

4.For the treatment of metastatic non-small cell lung cancer in adult patients who develop EGFR T790M mutation-positive disease after or during treatment with EGFRtyrosine kinase inhibitors (TKI).

Mechanism of action:

Osimertinib is an epidermal growth factor receptor(EGFR)tyrosine kinase inhibitor(TKI), which is related to some mutations of EGFR Forms(T790M, L858R and exon 19deletion)combine. These mutations pass through the front lineEGFR-TKIs predominate in non-small cell lung cancer tumors after treatment. As a third-generation tyrosine kinase inhibitor, osimertinib is specific for the gate-keeper T790M mutation, which increases the binding activity of ATP to EGFR and leads to poor prognosis in advanced disease. Additionally, osimertinib has been shown to avoid wild-type EGFR during treatment, thereby reducing nonspecific binding and limiting toxicity.

Usage and dosage:

Take 80 mg orally once a day.

Side effects of osimertinib include:

1.Digestive system reaction: One of the most common side effects is digestive system reaction, which may manifest as diarrhea, nausea, loss of appetite, constipation, stomatitis and other symptoms. Among them, diarrhea is the most common digestive system reaction, which may lead to increased stool frequency and abnormal stool shape.

2.Skin reaction: One of the common side effects is skin reaction, which may manifest as rash, dry skin, nail toxicity, skin itching and other symptoms. Especially if rash occurs, you should stop taking the medicine immediately and consult a doctor.

3.Eye diseases: May cause eye diseases, such as dry eye syndrome, blurred vision, keratitis, cataracts, etc. Regular eye examinations should be performed while using osimertinib.

4.Other adverse reactions: It may also cause other adverse reactions, such as cough, fatigue, back pain, headache, etc. In rare cases, patients may develop serious complications, such as infectious pneumonia, venous thromboembolism, etc.

You should pay attention to the following while taking osimertinib:

1.Special Precautions: Avoid driving or operating machinery as symptoms of fatigue may occur. Regularly check liver function, electrocardiogram, heart function, electrolytes, etc.

2.Food and drinks: Avoid eating foods containing furanocoumarins (such as grapefruit, citrus, etc.), and avoid taking osimertinib with strong tea to avoid affecting drug absorption.

Osimertinib may interact with certain drugs, such asCYP3A4 inhibitors or inducers, St. John's wort, etc. Always consult your doctor if you need to use other medications while taking osimertinib.

Osimertinib should be used with caution in pregnant and lactating women.