ALTO-100

ALTO-100 is a first-in-class, oral small molecule drug candidate being developed by Alto Neuroscience for the treatment of major depressive disorder (MDD) and bipolar depression. The drug functions by potentiating brain-derived neurotrophic factor (BDNF) signaling, likely acting as an agonist of the tropomyosin receptor kinase B (TrkB), to promote neuroplasticity and neurogenesis. ALTO-100 is a key asset in Alto's Precision Psychiatry Platform, which utilizes a specific cognitive biomarker—a verbal memory deficit—to identify patients who are biologically predisposed to respond to the treatment. In October 2024, Alto announced that a Phase 2b study in MDD failed to meet its primary endpoint of significant improvement in Montgomery-Åsberg Depression Rating Scale (MADRS) scores compared to placebo, although the drug demonstrated a favorable safety and tolerability profile. Development continues in other indications, including bipolar depression.