Day One Biopharmaceuticals (Servier)

Day One Biopharmaceuticals, based in Brisbane, California, and formerly listed as DAWN, is a paediatric-first oncology company whose tovorafenib became the first targeted therapy approved for childhood low-grade glioma driven by BRAF fusions, following dabrafenib with trametinib (2023) for BRAF V600E tumours. Ojemda, its brand of tovorafenib, was approved in the United States in 2024 on the FIREFLY-1 trial, Ipsen holds the rights outside the United States, the LOGGIPY-2 phase 3 tests it in the first-line setting, and pimasertib, a MEK inhibitor, is being developed in combinations. OnCo links it to glioma and paediatric low-grade glioma and to the bottleneck of rare and paediatric cancers without markets, which its model of developing drugs for children first is meant to answer. In January 2026 it completed the purchase of Mersana Therapeutics, adding the antibody-drug conjugate emiltatug ledadotin for adenoid cystic carcinoma, and on 23 April 2026 Servier completed its acquisition of Day One for 21.50 dollars a share in cash, about 2.5 billion dollars in equity value. Whether a paediatric-first programme keeps its priority inside a larger company is the open question now. Tovorafenib has its own page.