Will osimertinib cause thrombocytopenia in the treatment of lung cancer?

Osimertinib is a targeted drug for patients with non-small cell lung cancer who have EGFR gene mutations. Although it mainly exerts anti-tumor effects by selectively inhibiting EGFR tyrosine kinase activity, in clinical application, some patients have experienced thrombocytopenia.

The thrombocytopenia caused by osimertinib may be related to the drug's inhibition of bone marrow hematopoietic function, but the specific mechanism is not yet fully understood. Studies have shown that osimertinib may cause thrombocytopenia by affecting platelet production and/or disrupting the balance of platelets. Thrombocytopenia can cause coagulation dysfunction, manifesting as mucosal (such as nasal mucosa, oral mucosa, gums, gastrointestinal mucosa, urogenital tract, etc.) bleeding, ecchymosis, purpura and other symptoms. In severe cases, it may also lead to internal bleeding and intracranial hemorrhage, which is life-threatening.

According to clinical data, a certain proportion of patients in clinical trials of osimertinib experienced thrombocytopenia. For example, in some studies, 54% of patients experienced thrombocytopenia, with 1.2% of patients experiencing grade 3 or grade 4 thrombocytopenia (according to the adverse reaction grading criteria).

For patients whose platelet count drops rapidly and is below a certain level (such as50×10^9/L), osimertinib treatment should be suspended after ruling out other causes.

Drug treatment such as intravenous injection of gamma globulin (for immune drug-induced thrombocytopenia) or other white-elevating drugs.

Osimertinib may cause thrombocytopenia in the treatment of lung cancer, but the specific mechanism is not fully understood. For patients with thrombocytopenia, appropriate treatment measures should be taken according to the specific situation to ensure the patient's safety. At the same time, patients should regularly monitor platelet counts during treatment with osimertinib to detect and manage thrombocytopenia in a timely manner.