Autobahn Therapeutics Begins Phase 2 Trial of ABX-002 for Bipolar Depression

SAN DIEGO—Autobahn Therapeutics, a biotech firm focused on innovative treatments for neuropsychiatric and neuroimmunologic conditions, has embarked on a Phase 2 clinical trial for ABX-002. This trial will assess the efficacy of ABX-002, a selective thyroid hormone beta receptor agonist, as an additional therapy for adults suffering from bipolar depression. The primary aim of the study is to establish both biological and clinical proof of concept for ABX-002 in treating bipolar depression, which will inform future clinical development strategies for the company.

Bipolar depression is notoriously challenging to manage due to its complex and burdensome symptoms. According to Dr. Roger McIntyre, a Psychiatry and Pharmacology professor at the University of Toronto, individuals with bipolar disorder often endure long-lasting depressive periods and struggle to benefit from existing treatment options. Documented evidence over several decades has supported the use of thyroid hormone as an adjunctive therapy in treating bipolar depression, laying the groundwork for rigorous evaluation of a potent, brain-targeted TRβ agonist like ABX-002. This treatment has the potential to become a promising therapeutic alternative for patients who do not respond adequately to current medications.

The Phase 2 trial is structured as an open-label study involving 30 adults experiencing depressive episodes associated with bipolar I and II disorders. The study will employ neuroimaging assessments alongside validated clinical scales to examine changes in metabolites linked to brain energy metabolism, as well as improvements in depressive symptoms. The primary endpoints include assessing the correlation between changes from baseline levels of nucleoside triphosphate (NTP) and phosphocreatine (PCr) in the brain, evaluated using phosphorus magnetic resonance spectroscopy imaging (31P-MRS), and the percentage change in the Hamilton Depression Rating Scale-17 (HAMD-17) over a six-week period. Secondary and exploratory endpoints will involve further changes from baseline in the HAMD-17 and HAMD-29 scores, as well as other neuroimaging assessments, including resting state functional magnetic resonance imaging (rs-fMRI) to measure brain activity. Autobahn plans to release topline data from this trial in the latter half of 2025.

Gudarz Davar, M.D., Executive Vice President and Head of Research and Development at Autobahn Therapeutics, expressed enthusiasm about the trial's initiation. He highlighted ABX-002’s potential to revolutionize treatment approaches for bipolar depression, especially for patients who do not find adequate relief with their current antidepressants. Current clinical evidence for ABX-002 suggests it functions as a centrally-active, differentiated thyromimetic with a favorable safety profile. This trial marks an expansion of Autobahn's clinical depression program, complementing the ongoing AMPLIFY trial for major depressive disorder (MDD) and setting the stage for two significant trial results in 2025. These developments are key steps toward fulfilling the company's mission to meet the unmet needs of patients with depression globally.

ABX-002 is also undergoing evaluation in the ongoing AMPLIFY Phase 2 trial, which is focused on its role as an adjunctive treatment for patients with major depressive disorder. Results from this trial are similarly anticipated in late 2025.

Autobahn Therapeutics is dedicated to developing a range of clinical candidates for neuropsychiatric and neuroimmunologic disorders, using its innovative brain-targeting chemistry platform. By fine-tuning CNS exposure and targeting validated clinical and biological markers, the company aims to create new therapeutic opportunities. The lead candidate in Autobahn's pipeline is ABX-002, a thyroid hormone receptor beta agonist designed as an auxiliary treatment for major depressive disorder and bipolar depression. Based in San Diego, Autobahn Therapeutics continues to push the frontiers of treatment for complex neurological conditions.