Prior to regulatory approval by the U.S. Food and Drug Administration (FDA) and foreign regulatory authorities, patients gain access to investigational treatments, including BioXcel Therapeutics product candidates, by participating in clinical trials. In certain cases, when it is not possible for a patient to participate in a clinical trial and all other available medical options have been exhausted, a patient’s doctor may attempt to seek special access to an investigational product candidate for that patient outside of a clinical trial. This is known, among other terms, as expanded access. For a patient to obtain access to an investigational product candidate through expanded access, the patient’s physician, the drug’s sponsor, and the regulatory authority in the physician’s country of practice must all approve the use.