Day One Biopharmaceuticals, Inc. (“Day One” or the “Company”) is a clinical-stage biopharmaceutical company dedicated to developing and commercializing targeted therapies for patients of all ages with genetically defined cancers. The Company is initially focusing its clinical development efforts on pediatric patients living with cancer. Day One’s lead candidate, DAY101, is an oral, brain-penetrant, highly-selective type II pan-RAF kinase inhibitor. The Company’s second product candidate, pimasertib, is an oral, highly-selective small molecule inhibitor of mitogen-activated protein kinase kinases 1 and 2 (MEK), a key signaling node in the MAPK pathway.