Phase 2b Study of ALTO-100 in MDD

The purpose of this study is to determine efficacy differences between ALTO-100 and placebo, used either as monotherapy or adjunctively to an antidepressant, related to patient characteristics.

Inclusion Criteria:Have a diagnosis of moderate to severe major depressive disorder (MDD)At baseline, either not taking an antidepressant medication, or currently taking a single SSRI, SNRI, mirtazapine, or bupropion for at least 6 weeks with no dose modifications in the past 2 weeksWilling to comply with all study assessments and proceduresMust not be pregnant or breastfeeding at time of enrollment or throughout studyExclusion Criteria:Evidence of unstable medical conditionDiagnosed bipolar disorder, psychotic disorder, or dementiaCurrent moderate or severe substance use disorderHas a history of hypersensitivity or allergic reaction to ALTO-100 or any of its components/excipientsConcurrent or recent participation in another clinical trial for mental illness involving an investigational product or device