Progressive Multifocal Leukoencephalopathy (PML). People with weakened immune systems can get progressive multifocal leukoencephalopathy (PML) (a rare, serious brain infection caused by a virus). Although unlikely while receiving ENTYVIO, a risk of PML cannot be ruled out. PML can result in death or severe disability. There is no known treatment, prevention, or cure for PML. Tell your healthcare provider right away if you have any of the following symptoms: confusion or problems thinking, loss of balance, change in the way you walk or talk, decreased strength or weakness on one side of the body, blurred vision, or loss of vision., See ENTYVIO treatment options, infusion and subcutaneous injection, for Crohn's disease and ulcerative colitis. See Safety and Prescribing Information., What is ENTYVIO? ENTYVIO (vedolizumab) is a biologic used to treat Crohn’s disease and ulcerative colitis when certain other medicines haven’t worked well enough or could not be tolerated. Doctors have prescribed ENTYVIO for over 10 years. With ENTYVIO, there are options ENTYVIO can be administered 2 different ways, by IV infusion or by a self-administered injection, also known as the .