PFL-241

PFL-241 (also known as STX-241) is a highly selective, orally bioavailable, fourth-generation small molecule tyrosine kinase inhibitor (TKI) designed to target mutant forms of the epidermal growth factor receptor (EGFR), specifically addressing resistance mutations in non-small cell lung cancer (NSCLC). It is engineered to inhibit EGFR Exon 19 or 21 mutations that co-occur with the C797S mutation—a well-characterized resistance mechanism that emerges in patients treated with third-generation EGFR inhibitors. PFL-241 is brain penetrant and has been developed for use in patients with locally advanced or metastatic NSCLC who have developed this "double mutant" disease. The drug is currently being evaluated as monotherapy in Phase I/II clinical trials for safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy[1][2][3][4][5].