A Study to Assess the Efficacy, Safety and Tolerability of VLS-01 Buccal Film, Compared to Placebo in Patients With Treatment Resistant Depression (ELUMINA)

Inclusion Criteria: * Participant must be 18 to 65 years of age inclusive at the time of signing the Informed Consent. * Has a diagnosis of recurrent moderate or severe MDD without psychotic features or single- episode MDD with duration greater than or equal to 3 months without psychotic features and is currently experiencing a major depressive episode. * Onset of first episode of MDD occurred before age 55. * Has not responded to an adequate dose and duration of at least two and no more than five antidepressant medications for the current depressive episode, as determined by the Massachusetts General Hospital Antidepressant Treatment Response Questionnaire (MGH- ATRQ). * Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in the protocol. Exclusion Criteria: * Has a current or prior DSM-5-TR diagnosis of a schizophrenia spectrum and other psychotic disorder, substance/medication-induced psychotic disorder, bipolar and related disorder, or any disorder with psychotic features. * Has a moderate or severe substance use disorder (drug, alcohol, or tobacco) within the 6 months before Screening and/or history of moderate or severe substance use disorder (drug alcohol) within the previous 1 year before Screening * Has a history of, or current signs and symptoms of, diseases or conditions that would make participation not be in the best interest (e.g., compromise the wellbeing) of…