Day One Biopharmaceuticals, Inc. is a clinical-stage biopharmaceutical company. It is focused on developing and commercializing targeted therapies for patients of all ages with genomically-defined cancers. It seeks to identify, acquires, and develops product candidates that target high-value oncogenic drivers in cancers with unmet need, with an initial focus on pediatric patients. Its lead product candidate, DAY101 (tovorafenib), is an oral, brain-penetrant, highly selective type II pan-rapidly accelerated fibrosarcoma (pan-RAF), kinase inhibitor. Tovorafenib is also used for the treatment of low-grade gliomas (LGGs). Its 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. It has initiated a phase II trial of tovorafenib for pediatric patients with relapsed or progressive low-grade glioma (pLGG), the common brain tumor diagnosed in children.