ABX-002 · program

Elunetirom (ABX-002) for Major depressive disorder

Phase 2RecruitingAutobahn Therapeutics, Inc.

Indications for ABX-002: Bipolar depression · Phase 2 Major depressive disorder · Phase 2

Adjunctive major depressive disorder. Phase 2 AMPLIFY (NCT06633016): a randomized, double-blind, placebo-controlled (1:1) trial of once-daily oral ABX-002 added to a stable-dose SSRI/SNRI in adults (18-65) with moderate-to-severe MDD and inadequate response to current antidepressant therapy (MADRS >24). Primary endpoint is change from baseline in HAMD-17 at Week 6. Trial initiation announced 16 Sep 2024 (ClinicalTrials.gov actual start 20 Sep 2024); enrollment target 230; primary completion June 2026 (estimated). Per the 4 Jun 2026 company update, topline data are expected in the third quarter of 2026; no results have been reported and the trial remains recruiting. FDA Fast Track designation was granted for adjunctive bipolar depression only and does NOT extend to this MDD indication.

Data current as of

Development timeline

Phase 2Sept 2024 – Sept 2026
  1. UpcomingAMPLIFY Phase 2 topline (adjunctive MDD): HAMD-17 change at Week 6 vs. placebo, expected Q3 2026.↗
  2. Autobahn announced initiation of the AMPLIFY Phase 2 trial of ABX-002 as an adjunctive treatment for major depressive disorder (randomized, double-blind, placebo-controlled, ~230 patients, 6-week HAMD-17 primary endpoint). ClinicalTrials.gov records an actual start date of 20 Sep 2024.↗

Readouts

  • Q3 2026AnticipatedTopline dataNCT06633016

    AMPLIFY Phase 2 topline (adjunctive MDD): HAMD-17 change at Week 6 vs. placebo, expected Q3 2026. ↗

Clinical trials in Major depressive disorder

NCT06633016Phase 2Recruitingn=230

A Phase 2 Randomized, Double-Blind, Placebo-Controlled Study of ABX-002 for the Adjunctive Treatment of Major Depressive Disorder (AMPLIFY)

Started Sept 2024· Primary completion Jun 2026· 📍 50 sites across 1 country (United States)

Formulations

FormulationRouteRegimenPharmacokinetics
Elunetirom oral solutionOral solution in 1-mL cyclic olefin polymer prefilled syringes, taken on an empty stomach in the morning followed by 240 mL (8 oz) of water
Oral, once-daily brain-penetrant small-molecule prodrug (prodrug of LL-340001); dosed once daily for six weeks in the Phase 2 adjunctive bipolar-depression trial
OralOnce daily—

Mechanism of action (compound-wide)

Elunetirom (ABX-002) is a blood-brain-barrier-penetrant amide prodrug that is cleaved by fatty acid amide hydrolase (FAAH) to the active metabolite ABX-002A (LL-340001), a potent, selective, centrally acting agonist of thyroid hormone receptor beta (TRbeta / THRB). Selective CNS TRbeta agonism is hypothesized to relieve depression by enhancing neuronal mitochondrial/energy metabolism (reflected in 31P-MRS brain phosphate measures) and neuroplasticity, while the prodrug design and TRbeta selectivity limit the peripheral cardiac/metabolic effects of systemic thyroid hormone. No clean published TRbeta binding constant (Ki/EC50) is catalogued for elunetirom or ABX-002A in IUPHAR/GtoPdb, so affinity is left null.

TargetActionAffinity
TRbetaprimaryTHRBAgonist—ⓘ

← Full ABX-002 compound page (identity, identifiers, all indications)

Sources

  1. AMPLIFY: Phase 2 randomized, double-blind, placebo-controlled study of adjunctive ABX-002 in major depressive disorder (NCT06633016) — ClinicalTrials.gov
  2. Autobahn announces initiation of its AMPLIFY Phase 2 trial of ABX-002 as an adjunctive treatment for major depressive disorder (16 Sep 2024) — Autobahn Therapeutics
  3. Autobahn reports positive Phase 2 topline data for elunetirom in bipolar depression (4 Jun 2026) — Autobahn Therapeutics
  4. Elunetirom (ABX-002, ligand 12973) - brain-penetrant TRbeta agonist amide prodrug (FAAH-cleaved to ABX-002A) — IUPHAR/BPS Guide to Pharmacology
  5. Study of ABX-002 for the Adjunctive Treatment of Bipolar Depression (AMPLIFY-BD), NCT06869187 — ClinicalTrials.gov