Otonomy, Inc., a clinical-stage biopharmaceutical company, announced that FDA has cleared the company's Investigational New Drug application (IND) for tinnitus product candidate OTO-311, a sustained-exposure formulation of the N-Methyl-D-Aspartate (NMDA) receptor antagonist, gacyclidine.

The IND clearance enables Otonomy to initiate a phase 1 dose escalation clinical safety trial of OTO-311 in normal healthy volunteers. OTO-311 will be given as a single unilateral intratympanic injection and subjects will be observed for four weeks following dosing.

Tinnitus is the medical term for hearing noise when there is no outside source of the sound. It is often described as a ringing in the ear but can also sound like roaring, clicking, hissing or buzzing. Tinnitus sufferers may have trouble hearing, concentrating, working and sleeping.

"Despite the debilitating nature of tinnitus that impacts millions of Americans, including a high proportion of military veterans, there is no cure and there are no FDA-approved drug treatments," said David A. Weber, Ph.D., president and chief executive officer of Otonomy.

"Initiating this phase 1 trial for OTO-311 before the end of 2015 meets our commitment to investors and also serves as an important first step towards our goal of bringing a single-dose intratympanic treatment to tinnitus sufferers."

The American Tinnitus Association reports that approximately 16 million patients in the United States have tinnitus symptoms severe enough to seek medical attention, and about two million patients cannot function on a normal day-to-day basis. Furthermore, the United States Department of Defense reports that tinnitus accounts for the most prevalent service-connected disability among veterans and that the costs of service-related tinnitus are estimated to exceed $2 billion. While the most common cause of tinnitus is exposure to loud noise, a number of other factors can be involved including heart or blood vessel problems, hormonal changes in women, ear and sinus infections, certain medications and thyroid problems. People with severe tinnitus may have trouble hearing, working and sleeping. At this time, there is no cure for tinnitus and there are no FDA-approved drugs for treating this debilitating condition.

OTO-311 is a sustained-exposure formulation of the potent and selective N-Methyl-D-Aspartate (NMDA) receptor antagonist gacyclidine. Clinical studies, including pilot studies conducted with gacyclidine, support the use of NMDA receptor antagonists as potential treatments for tinnitus. In 2013, Otonomy acquired certain assets and rights to intellectual property related to the use of gacyclidine for the treatment of tinnitus from an affiliate of NeuroSystec Corporation, a company founded by serial entrepreneur Alfred Mann. In 2014, Otonomy entered into an exclusive license agreement with Ipsen that enables Otonomy to utilize Ipsen's clinical and non-clinical gacyclidine data to support worldwide development and regulatory filings for OTO-311. The clinical data are from several phase 1 and phase 2 trials conducted by Ipsen in more than 300 patients who received treatment with systemic gacyclidine as a potential neuroprotectant in various neurologic trauma indications. OTO-311 utilizes Otonomy's proprietary drug delivery technology to achieve sustained exposure of gacyclidine in the inner ear from a single intratympanic (IT) injection.