Autobahn Therapeutics said the FDA granted Fast Track status to elunetirom (ABX-002), an investigational oral small molecule prodrug designed to activate CNS thyroid hormone receptors as an adjunctive treatment for bipolar depression. The designation is not approval, but it can increase regulatory interaction frequency and potentially enable expedited review later. Elunetirom is being evaluated in the Phase 2 AMPLIFY-BD trial (NCT06869187), with topline results expected in Q2 2026. Autobahn positioned the program as aiming to limit peripheral thyroid receptor effects that can accompany systemic thyroid hormone exposure. The Fast Track step adds regulatory momentum ahead of clinical readouts in a space where effective options for bipolar depression remain limited.