Ultragenyx is a biopharmaceutical company that develops and commercializes treatments for rare and ultra-rare genetic diseases, including the monoclonal antibodies Crysvita and Evkeeza, the enzyme replacement therapy Mepsevii, and small-molecule therapies like Dojolvi, alongside a pipeline of gene therapy candidates targeting inherited metabolic and neurological disorders. The company generates revenue through direct product sales, royalty arrangements with commercial partners, milestone payments from collaborations, and supply agreements, while serving a customer base of specialized physicians, hospitals, specialty pharmacies, and government and private payors across the U.S., Canada, Europe, and Latin America. The business model depends on regulatory approval of pipeline candidates, establishing favorable pricing and reimbursement, penetrating dispersed patient populations despite the rarity of target conditions, managing complex manufacturing operations for gene therapies, and maintaining orphan drug exclusivity protections against generic and biosimilar competition.