Shares of Day One Biopharmaceuticals Inc. /zigman2/quotes/227052400/composite DAWN +7.10% gained 9.4% in premarket trading on Monday after the company said its experimental glioma treatment received an orphan designation in Europe. The drug candidate has already received a Breakthrough Therapy designation from U.S. regulators for one indication and an orphan designation as a treatment for malignant glioma. In the U.S., an orphan-drug designation supports developing treatments for diseases that affect fewer than 200,000 people. Gliomas are a type of nervous system tumor. Day One went public last month.