Day One Biopharmaceuticals is a commercial-stage oncology company focused on targeted therapies for cancer patients of all ages. Its core product is OJEMDA (tovorafenib), an FDA-approved once-weekly oral RAF kinase inhibitor for pediatric low-grade glioma (pLGG), the most common brain tumor in children. OJEMDA targets BRAF alterations, which drive roughly 50-60% of pLGG cases. OJEMDA is the only approved systemic therapy for pLGG patients with BRAF fusions — the largest subtype — where older type I RAF inhibitors are actually contraindicated. Day One sells OJEMDA exclusively in the U.S. through a lean commercial team of 18 sales reps covering roughly 200 accounts. Outside the U.S., Day One has licensed all commercial rights to Ipsen in exchange for upfront payments, equity investment, milestones, and tiered royalties. Revenue scales with new patient starts and treatment persistence — pLGG is a chronic disease, and commercial treatment durations are trending toward 19 months, creating a compounding revenue dynamic as new patients layer onto an existing base. Beyond OJEMDA, Day One is building a pipeline of antibody-drug conjugates through its "search and development" model, acquiring or in-licensing externally developed assets and advancing them to registration. Key pipeline assets include Emi-Le, a B7-H4-directed ADC targeting adenoid cystic carcinoma, and DAY301, a PTK7-targeted ADC in Phase 1 dose escalation. Day One is also running FIREFLY-2, a Phase 3 trial of OJEMDA as frontline pLGG therapy, with a top-line readout expected mid-2027.