AZ7550

AZ7550 is a primary active metabolite of osimertinib, a third-generation oral and irreversible tyrosine kinase inhibitor developed for the treatment of non-small cell lung cancer (NSCLC) with sensitizing epidermal growth factor receptor (EGFR) mutations. AZ7550 circulates at approximately 10% of the plasma concentration of osimertinib, with potency similar to the parent drug. Like osimertinib, AZ7550 selectively and irreversibly binds to mutant forms of EGFR such as T790M, L858R, and exon 19 deletion mutations, and exhibits significantly lower activity against wild-type EGFR. AZ7550 is produced in patients receiving osimertinib and has similar molecular targeting and clinical pharmacology properties to osimertinib. Its safety, blood concentrations, and pharmacokinetics are clinically monitored in patients treated with osimertinib for NSCLC[3][4][5][7][9].