Study of ABX-002 for the Adjunctive Treatment of Depressive Episodes Associated With Bipolar Disorder in Adults

A Phase 2 Open-label Study of the Effect of Adjunctively Administered ABX-002 in Adults With Bipolar Disorder Experiencing an Episode of Depression

The goal of this clinical trial is to learn if ABX-002 added to participants' existing treatment(s) can improve clinical symptoms of depression and to learn about potential effects on brain chemistry that may correlate with antidepressive effects.

This is a single treatment arm, open-label, Phase 2 study of ABX-002 in up to30 adults with bipolar depression. A subset of these participants will undergo brain imaging. Five healthy volunteer participants will also be enrolled and receive no drug treatment, undergoing 2 imaging sessions to confirm instrument and test - retest method reliability control.

For bipolar disorder participants who are experiencing an episode of depression, the study will include 4 study periods:

1. Screening Period of up to 5 weeks
2. 6-week Treatment Period
3. 2-week post dose Safety Follow-up Period.
4. 6-month postdose targeted safety follow-up period

For healthy volunteers, the study will include 2 study periods:

1. Screening Period of up to 3 weeks
2. Imaging Period of up to 3 weeks.

Study Overview

• Status: Active, not recruiting
• Conditions: Bipolar Disorder Depression
• Intervention / Treatment: Drug: ABX-002

• Study Type: Interventional
• Enrollment (Estimated): 35
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • California
    • Walnut Creek, California, United States, 94596
      • Autobahn Site #213
  • Connecticut
    • Cromwell, Connecticut, United States, 06416
      • Autobahn Site #201
    • Hartford, Connecticut, United States, 06106
      • Autobahn Site #210
  • Florida
    • Miami, Florida, United States, 33014
      • Autobahn Site #212
  • Illinois
    • Chicago, Illinois, United States, 60622
      • Autobahn Site #215
  • Massachusetts
    • Worcester, Massachusetts, United States, 01608
      • Autobahn Site #216
  • New Jersey
    • Cherry Hill, New Jersey, United States, 08002
      • Autobahn Site #208
    • Hamilton, New Jersey, United States, 08690
      • Autobahn Site #209
    • Marlton, New Jersey, United States, 08053
      • Autobahn Site #205
  • New York
    • Brooklyn, New York, United States, 11235
      • Autobahn Site #203
    • New York, New York, United States, 10016
      • Autobahn Site #207
    • New York, New York, United States, 10019
      • Autobahn Site #211
    • Staten Island, New York, United States, 10314
      • Autobahn Site #204
  • Washington
    • Bellevue, Washington, United States, 98007
      • Autobahn Site #214

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria (For Bipolar Disorder Depression Patients):

• Current diagnosis of bipolar disorder for at least 2 years
• DSM-5-TR criteria for bipolar disorder based on Structured Clinical Interview for the DSM-5 - Clinical Trials Version (SCID-5-CT) at Screening
• Has a current depressive episode with or without mixed features, but not psychotic features, with duration ≥ 6 weeks and ≤ 24 months
• 17-item Hamilton Rating Scale for Depression total score ≥ 22 at Screening and Baseline
• Young Mania Rating Scale total score ≤ 12 at Screening and Baseline
• For participants who will undergo brain imaging: Able to undergo imaging sessions using Magnetic Resonance Spectroscopy/Imaging with no history of aborted scanning due to anxiety, claustrophobia, or unable to scan due to an incompatible implant/device
• Taking at least one mood stabilizer (e.g., lithium, valproate, lamotrigine) and/or second-generation antipsychotic (SGA, atypical antipsychotic). All medications intended to treat the current episode of depression should be at an adequate and stable dose for ≥ 6 weeks prior to screening.

Exclusion Criteria (For Bipolar Disorder Depression Patients):

• History of > 4 manic, hypomanic, or depressive episodes within a one-year period (rapid cycler; DSM-5-TR) in the last 2 years
• History of schizophrenia or schizoaffective disorder (DSM-5-TR) or a psychotic disorder unrelated to bipolar disorder
• Concurrent or history of active symptoms within the past 2 years of obsessive-compulsive disorder, or posttraumatic stress disorder, according to DSM-5-TR criteria
• Diagnosis of a personality disorder (DSM-5-TR)
• Evident risk of suicide at Screening or Baseline
• Inadequate response to more than 2 second-generation antipsychotic treatments (including their current treatment) in their current episode of depression in bipolar disorder despite an adequate dose and duration (> 6 weeks at approved or standard of care doses)
• Received any course of deep brain stimulation in participant's lifetime or plans to receive deep brain stimulation during the study
• Treatment with electroconvulsive therapy (for psychiatric/therapeutic purposes) or repetitive transcranial magnetic stimulation, or treatment with ketamine or esketamine for the current episode and received any of those treatments within 12 months prior to Screening
• Started new psychotherapy or had a change in the intensity of psychotherapy within 6 weeks before Screening
• Prior use of psychedelics for the treatment of depression
• Refusal to abstain from consumption of excessive amounts of alcohol during the study
• History of uncontrolled, clinically significant neurological (including prior cerebrovascular accident [stroke] or chronic seizures), cardiovascular, gastrointestinal, respiratory, renal, hepatic, immunological, hematological, endocrine (including uncontrolled diabetes), or other medical disorder, including cancer
• Current use of high dose (> 4 mg/day lorazepam equivalents) benzodiazepine anxiolytic and/or hypnotic medication
• Cannabinoids (marijuana, cannabis, tetrahydrocannabinol [THC], cannabidiol [CBD]) in any form or use frequency.
• History or presence of cataract on ophthalmic examination (including slit-lamp), glaucoma, inflammatory eye disease prior ophthalmic surgical procedures or laser surgery in either eye.

Inclusion Criteria (For Healthy Volunteers):

• In good health, based on medical history, physical examination (including neurological examination), vital sign measurements, and laboratory safety tests obtained at the Screening Visit
• Able to undergo imaging sessions using Magnetic Resonance Spectroscopy/Imaging, with no history of aborted scanning due to anxiety, claustrophobia, or an incompatible implant/device

Exclusion Criteria (Healthy Volunteers):

• Mentally or legally incapacitated, has significant emotional problems at the time of the Screening Visit, or is expected to have potential for mental incapacitation during the conduct of the study
• History of any illness (including psychiatric illness)
• Participation in an investigational drug or device study where last dosing of previous drug is within 30 days
• Prior use of psychedelics within the past year
• Refusal to abstain from consumption of excessive amounts of alcohol during the study
• Cannabinoids (marijuana, cannabis, tetrahydrocannabinol [THC], cannabidiol [CBD]) in any form or use frequency are not allowed.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: No Treatment + Imaging Sessions; Healthy Volunteers will not receive any study treatment as their only assessment is 2 imaging sessions (baseline and retest)
Experimental: ABX-002 + at least one mood stabilizer and/or single second-generation antipsychotic (SGA); Participants will continue all medications intended to treat the current episode of depression for the duration of the study in addition to ABX-002	Drug: ABX-002; ABX-002 oral solution in 1-mL cyclic olefin polymer prefilled syringes, taken on an empty stomach first thing in the morning followed by 240 mL (8 oz) of water.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline for 17-item Hamilton Rating Scale for Depression (HAMD-17)	HAMD-17 is a clinician-based assessment of depressive symptoms. Higher scores indicate worse symptoms. A score of 0-9 is generally accepted to be within the normal range (or in clinical remission), while a score of greater than 17 indicates moderate to severe depression symptoms.	Weeks 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline for 29-item Hamilton Rating Scale for Depression (HAMD-29)	HAMD-29 is a clinician-based assessment of depressive symptoms. Higher scores indicate worse symptoms. A score of 0-7 is generally accepted as not depressed, 8-16 indicates mild depression, 17-23 indicates moderate depression, and 24 and above indicates severe depression.	Weeks 6
Change from baseline in 6-item Hamilton Rating Scale for Depression (HAMD-6)	Six-item scale used to assess the core symptoms of depression. HAMD-6 is a shorter version of HAMD-17. The higher the total score the more severe the depression.	Weeks 6
Correlation of change from baseline in the anterior cingulate cortex (ACC) nucleoside triphosphate/inorganic phosphate (NTP/Pi) concentrations with percentage change in 17-item Hamilton Depression Rating Scale (HAMD-17)	Utilizing 31P-Magnetic Resonance Spectroscopy (31P-MRS), a magnetic resonance imaging (MRI) method that measures high-energy phosphates in the brain	Week 6
Correlation of change from Baseline in the anterior cingulate cortex (ACC) phosphocreatine/inorganic (PCr/Pi) concentration with percentage change in 17-item Hamilton Depression Rating Scale (HAMD-17)	Utilizing 31P-Magnetic Resonance Spectroscopy (31P-MRS), a magnetic resonance imaging (MRI) method that measures high-energy phosphates in the brain	Week 6

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of plasma pharmacokinetics (PK)	Change in plasma concentrations of ABX-002	Weeks 2, 4, 6

Collaborators and Investigators

• Sponsor: Autobahn Therapeutics, Inc.
• Investigators: Study Director: Bridgette Franey, MD, Autobahn Therapeutics, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): March 28, 2025
• Primary Completion (Actual): April 22, 2026
• Study Completion (Estimated): September 24, 2026

Study Registration Dates

• First Submitted: February 18, 2025
• First Submitted That Met QC Criteria: March 4, 2025
• First Posted (Actual): March 11, 2025

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 21, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Bipolar Depression; BD Study; Adjunctive BD Study; elunetirom
• Additional Relevant MeSH Terms: Bipolar and Related Disorders; Mental Disorders; Mood Disorders; Bipolar Disorder
• Other Study ID Numbers: ABX-002-2002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No