Major depressive disorder drug progresses to Phase II trials


Alto Neuroscience has initiated a Phase II study to determine the pharmacodynamic effects of ALTO-203 in major depressive disorder (MDD) patients, as well as assess its safety, tolerability, and pharmacokinetics.

To date, ALTO-203 has demonstrated positive emotional and cognitive effects in healthy participants after a single dose.

The new study will evaluate these effects in patients with MDD to determine the potential of ALTO-203 as an antidepressant.

In January 2023, a Phase IIa study of Alto Neuroscience’s ALTO-100 demonstrated clear evidence of efficacy and a favourable safety record in patients with MDD.  

“This is the fifth Phase II study we have initiated across our pipeline, a milestone that marks significant progress in our efforts to redefine mental healthcare through our Precision Psychiatry Platform,” said Jessica Powell, Chief Development Officer of Alto Neuroscience.

“In a Phase I study, ALTO-203 demonstrated an acute increase in positive emotion relative to placebo and across several dosage levels. We look forward to completing this proof-of-concept study in patients as we believe this response may be an important attribute of an antidepressant to benefit patients with MDD and higher levels of anhedonia specifically.”

ALTO-203 is a novel small molecule histamine H3 receptor inverse agonist being developed for the treatment of patients with MDD and elevated anhedonia, or the lack of motivation or pleasure.

The Phase II study will consist of two sequential double-blind, placebo-controlled treatment periods and examines two doses of ALTO-203 and placebo given as monotherapy in patients with MDD.

Alto expects to enrol approximately 60 adult participants with MDD and evidence of anhedonia, and report topline data from this study in the first half of 2025.

Diana Spencer, Senior Digital Content Editor, DDW

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