molecules of the month

The Henan EGFR inhibitor, dosimertinib, is a deuterated derivative of the approved covalent inhibitor, osimertinib. A metabolite of osimertinib, AZ5104, has lower selectivity for WT EGFR than mutant EGFR, which the authors suggest may contribute to some adverse events. Deuteration of osimertinib appears to reduce the formation of the AZ5104-like metabolite in vitro and in vivo. Dosimertinib appears to have a wider therapeutic window in mice than osimertinib based on doses at which mouse body weight loss is observed, and is currently starting a Ph. I trial in China to evaluate this hypothesis in humans.