Visser S, Koolen SLW, de Bruijn P, et al. - Researchers examined the value of determining total exposure to pemetrexed in predicting efficacy and toxicity in advanced non–small-cell lung cancer (NSCLC). Moreover, they sought to determine alternative dosing schedules. Patients with advanced NSCLC receiving first- or second-line pemetrexed(/platinum) provided plasma samples weekly (cyclePK) and within 24 h (24hPK) after pemetrexed administration. The analysis revealed no increased PFS/OS in correlation to higher exposure to pemetrexed instead higher exposure was significantly correlated with increased occurrence of severe toxicity. Findings thereby support fixed dosing for decreasing interpatient pharmacokinetic variability and thereby possibly preventing toxicity, while preserving effectiveness.