Autobahn Therapeutics, Inc., a biotechnology company developing restorative treatments for people affected by neuropsychiatric disorders, today announced that full results from its Phase 2 AMPLIFY-BD trial were presented at Psych Congress 2026, which took place September 15-19 in New Orleans, Louisiana. Elunetirom, a novel, oral, once daily, brain-penetrant CNS thyroid hormone receptor agonist, achieved clinically meaningful benefit and statistical significance across the primary and all key secondary depression endpoints in AMPLIFY-BD, evaluating elunetirom as an adjunctive treatment in patients with bipolar I or bipolar II depression. The data support Autobahn’s plans to engage with regulatory agencies on a potential path to registration of elunetirom for bipolar depression, a prevalent disorder affecting approximately 7 million adults in the U.S.

“The thyroid-mood axis has been one of psychiatry’s most compelling mechanisms for decades, but also one of the least accessible,” said Roger S. McIntyre, M.D., FRCPC, Professor of Psychiatry and Pharmacology at the University of Toronto and global thought leader in depression and bipolar disorder. “Elunetirom is differentiated in its ability to engage that target selectively, without the peripheral effects that have historically limited the therapeutic use of thyroid hormone. From a treating perspective, what stands out most is that improvement continued to deepen through Week 6 across each endpoint, including the symptom domains that are hardest to move in bipolar depression – depressed mood, work and activity, and psychomotor slowing. These results are highly encouraging for what they could mean for the patient and physician community, and how we manage this challenging disorder.”

“The complete AMPLIFY-BD dataset is consistent with our topline results on every measure,” said Gudarz Davar, M.D., Chief Medical Officer and Head of Research and Development at Autobahn. “We observed meaningful improvements in both clinician-rated and patient-reported outcomes, at every time point evaluated. Participants went from losing nearly three days a week to their illness to losing less than half a day, and they reported getting back to work, and re-engaging with their families and in their social lives. We believe this is greatest outcome that can be offered to patients who struggle with depression, and one that remains difficult to achieve with currently available adjunctive options. I am very proud of our team’s execution of this trial and look forward to engaging with FDA to discuss a potential path to registration.”

AMPLIFY-BD Phase 2 Trial Results

AMPLIFY-BD was an open-label Phase 2 trial designed to evaluate the efficacy, safety, and tolerability of elunetirom as an adjunctive treatment in 21 adults with bipolar I or bipolar II disorder who were experiencing a moderate-to-severe major depressive episode, with a mean baseline HAMD-17 total score of 25.1. Patients received oral elunetirom 2.8 µg once daily for six weeks in addition to their existing mood stabilizer and/or atypical antipsychotic regimen, with or without an SSRI or SNRI. The primary endpoint was the change in the 17-item Hamilton Rating Scale for Depression (HAMD-17) total score from baseline to Week 6.

Primary Efficacy and Safety Results (Poster 62)

  • Primary endpoint achieved, with rapid and robust antidepressant response: Statistically significant improvement in HAMD-17, with a 16.8 point (p<0.001) mean reduction at Week 6, and mean reductions of 9.7 point (p<0.001) at Week 2 and 13.7 point (p<0.001) at Week 4, indicating rapid onset and a durable antidepressant effect.

  • High response and remission rates: 75% response rate and 50% remission rate at Week 6, building from 38.1% and 14.3% at Week 2 and 52.6% and 36.8% at Week 4.

  • Improvement across core depressive symptoms: Statistically significant improvement in the HAMD-6 sub-score, with a mean reduction of 9.0 points at Week 6 (p<0.001), and in each individual item, including depressed mood, work and activities, feelings of guilt, psychomotor retardation, psychic anxiety and general somatic symptoms, at every study visit. Clinically meaningful and statistically significant improvement was also observed on the HAMD-29 at all assessed time points, with a mean reduction of 22.9 points at Week 6 (p<0.001).

  • Sustained improvement in bipolar illness severity: Statistically significant improvement (p<0.001) on the Clinical Global Impressions-Bipolar Severity (CGI-BP-S) scale at all assessed time points, tracking closely with HAMD-17 improvement, with Spearman’s Rank Correlation Coefficients of 0.82, 0.90 and 0.89 at Weeks 2, 4 and 6, respectively.

  • Generally well-tolerated: Elunetirom was generally well-tolerated throughout the trial, with no severe or serious treatment-related adverse events reported. In addition, there was no observation of weight gain, extrapyramidal symptoms or tardive dyskinesia, and no clinically meaningful peripheral thyroid effects or ECG findings of concern. The most common treatment-related adverse events were dizziness (14.3%), diarrhea (9.5%) and decreased free thyroxine (9.5%).

Patient-Reported Outcomes (Poster 63)

  • Substantial improvements in functioning: Significant mean improvement from baseline of 62% in Sheehan Disability Scale (SDS) total score at Week 6 (p<0.001), with statistically significant improvements from baseline across all three domains of work and school, social and leisure, and family and home life.

  • Return of productivity: Significant 85% reduction from baseline in days lost due to illness at Week 6 (p<0.001), from 2.7 to 0.4 days per week, with a significant reduction in underproductive days.

  • Patient-reported symptom relief: Significant 36% improvement from baseline in Symptoms of Depression Questionnaire (SDQ) total score at Week 6 (p<0.001), and significant improvements on the Patient Global Impression of Improvement (PGI-I) at Weeks 2, 4 and 6, with no patient reporting a worsening of symptoms at any time point.

  • Alignment of patient- and clinician-reported improvement: Improvements reported by patients tracked closely with clinician-rated improvement, including Spearman’s Rank Correlation Coefficient of 0.94 between percent change in SDS total score and percent change in HAMD-17 total score at Week 6.

Elunetirom has been granted Fast Track designation by the U.S. Food and Drug Administration for the adjunctive treatment of bipolar depression.

In addition, Autobahn is evaluating elunetirom as an adjunctive treatment for MDD in its ongoing Phase 2 AMPLIFY trial (NCT06633016).

About Bipolar Depression

Bipolar depression, the depressive phase of bipolar disorder, affects approximately 7 million adults in the U.S. and represents one of the most debilitating chronic conditions in psychiatry. Bipolar disorder is characterized by extreme mood swings, including episodes of both mania (or hypomania) and depression. The depressive phase is the predominant and most disabling state for most patients, marked by persistent low mood, loss of interest, fatigue, and impaired functioning. Patients lose an average of more than one month of work each year and face elevated risks of hospitalization and suicide. More than half of patients do not receive adequate relief from currently available therapies, which are limited by modest efficacy and significant side effects, including weight gain, sexual dysfunction, movement disorders, and metabolic complications.

About Elunetirom

Elunetirom (ABX-002) is an investigational, oral, once daily, brain-penetrant small molecule prodrug that targets CNS thyroid hormone receptors (CNS-TRs). Elunetirom is believed to uniquely boost energy and plasticity in the brain through improving mitochondrial health, increasing cellular energy production, and driving neuroplastic changes in the CNS, offering a potentially fundamentally different mechanism to treat depression and other CNS disorders. Elunetirom is designed to enhance beneficial neurobiological activity at CNS-TRs while also reducing the liabilities of peripheral thyroid hormone receptor activity from the administration of synthetic thyroid hormone (e.g., triiodothyronine, T3), a treatment which has shown efficacy in numerous placebo-controlled human studies across MDD and bipolar disorder depression. In nonclinical and clinical studies, elunetirom has demonstrated optimized PK properties, target engagement in brain regions associated with depression, and a favorable safety and tolerability profile. Elunetirom has been granted Fast Track designation by the U.S. Food and Drug Administration for the adjunctive treatment of bipolar depression and is being evaluated in clinical studies as a potential adjunctive treatment for MDD and bipolar depression.

About Autobahn Therapeutics

Autobahn Therapeutics, Inc., is a biotechnology company developing a portfolio of neuropsychiatric clinical candidates leveraging its brain-targeting chemistry platform. Autobahn aims to unlock new therapeutic opportunities through precision tuning of CNS exposure, pursuing validated clinical and biologic targets, and guiding development with biomarkers. The company’s pipeline is led by elunetirom, a CNS thyroid hormone receptor (CNS-TR) agonist being developed as a potential adjunctive treatment for people with major depressive disorder and bipolar disorder depression, including those with atypical depression, a highly prevalent and underserved subpopulation of depression. For more information, visit www.autobahntx.com.

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