Autobahn Therapeutics has announced that the FDA has cleared its Investigational New Drug (IND) application for ABX-002, paving the way for a Phase 2 clinical trial to evaluate the drug as an adjunctive treatment for bipolar depression. The trial is expected to begin before the end of 2024.
ABX-002 is a highly potent, orally administered, selective thyroid hormone beta receptor (TRβ) agonist. It is designed to enhance the central nervous system (CNS) benefits of thyroid hormone biology, increasing drug concentrations directly in the brain.
Phase 2 Trial Design
The Phase 2 trial will assess ABX-002 as an adjunctive therapy in adult patients experiencing depressive episodes associated with bipolar I or bipolar II disorder. The study will evaluate the biological and clinical proof-of-concept of ABX-002 using multiple endpoints. These include changes in energy metabolism in the brain, as determined by phosphorus magnetic resonance spectroscopy (31P-MRS), and changes in patients’ depressive symptoms, as measured by the Hamilton Depression Rating Scale (HAMD).
Broader Clinical Program
ABX-002 is also currently under evaluation in the AMPLIFY Phase 2 trial as an adjunctive treatment for patients with major depressive disorder (MDD). Topline data from the AMPLIFY trial is anticipated in the second half of 2025.
About ABX-002
ABX-002 is designed to enhance the CNS benefits of thyroid hormone while minimizing the peripheral liabilities associated with synthetic thyroid hormones like triiodothyronine (T3). Thyroid hormone agonism has demonstrated activity on cellular energy metabolism pathways, which play a crucial role in regulating brain bioenergetics. This mechanism may be particularly effective for addressing symptoms of atypical depression, a prevalent and underserved sub-population of MDD. Nonclinical and clinical studies have shown that ABX-002 has optimized pharmacokinetic properties, target engagement in brain regions associated with depression, and a favorable safety and tolerability profile.
Executive Commentary
"We are thrilled to expand our depression treatment program with ABX-002 and evaluate its potential to safely address the debilitating symptoms of bipolar depression, a highly prevalent and potentially life-threatening disorder," said Kevin Finney, President and CEO of Autobahn. He noted that in the U.S. alone, seven million patients suffer from bipolar disorder, and there are limited safe and effective therapies specifically targeting depressive symptoms. "Our planned Phase 2 trial is designed to provide proof-of-concept for ABX-002 and inform further clinical development in bipolar depression."
