OTO-311 is a sustained-exposure formulation of the N-Methyl-D-Aspartate (NMDA) receptor antagonist gacyclidine in development for the treatment of tinnitus.

Tinnitus is most often described as a ringing in the ears but can also sound like roaring, clicking, humming, hissing or buzzing. People with severe tinnitus may have trouble hearing, concentrating, working and sleeping. At this time, there is no cure for tinnitus and there are no FDA-approved drugs for treating this debilitating condition. Historic and emerging clinical data provide support for the evaluation of NMDA receptor antagonists, including gacyclidine, for the treatment of tinnitus.

The goal of our OTO-311 program is to develop a sustained-exposure formulation of gacyclidine that will provide a full course of treatment from a single intratympanic (IT) injection. We have completed a Phase 1 clinical safety trial and selected a dose for evaluation in a Phase 2 clinical trial. Timing for initiating the Phase 2 trial has not been determined.