Doctors have struggled for years to deliver medication effectively to the inner ear, but two companies are vying to be first to introduce new treatments which, if successful, could together chalk up some $800 million in peak sales.

Pivotal drug–trial data from Otonomy Inc and Auris Medical Holding AG is expected to show whether two competing approaches can address ear disorders associated with hearing loss and balance.

Current therapy typically involves injecting steroids into the middle ear. The steroids are used off–label to treat sudden changes in hearing and balance. This approach requires patients to lie on their side, and avoid swallowing, or risk either the loss of the drug or possible side–effects.

"The steroids work, but the current method of delivering them is terrible," said Dr. Darius Kohan, chief of otology/neurotology at New York–based Lenox Hill Hospital.

San Diego–based Otonomy and Swiss biotech Auris propose delivering medicines using different gel–like formulations into the middle ear, for absorption by the inner ear.

Otonomy's drug, a formulation of an existing steroid, is being tested for use in Meniere's disease – a chronic, progressive condition characterized by dizziness, tinnitus and hearing loss that affects 600,000 Americans.

Auris's treatment is being evaluated for use in tinnitus – a perception of ringing in the ears, often a symptom of underlying disease. About 250,000 Americans are eligible for Auris's treatment.

No FDA–approved treatments exist for these diseases.

NO WINNER YET

At least four other companies also have ear drug trials under way, but are considered far behind. The group includes Nordmark Arzneimittel GmbH & Co, Sound Pharmaceuticals and Decibel Therapeutics, as well as Novartis AG.

Otonomy is expected to release late–stage data on its Meniere's trial in the second half of 2017.

The drug is expected to generate peak sales of $603 million, said SunTrust Robinson analyst Edward Nash.

The delivery technology that Otonomy is using for this treatment is already being utilized in its FDA–approved antibiotic. This, in a way, validates the company's technology, Nash said, also noting that Otonomy's approach does not require repeat injections to complete a course of treatment.

In contrast, Auris's technology necessitates multiple injections and requires patients to lie still for up to half an hour post administration.

Late stage data from Auris's European study is expected in 2018.

"Even if Auris is successful in their second tinnitus trial, they'd still have to conduct another U.S. trial to win FDA approval. If the Otonomy trial is positive, they can file right away for Meniere's," Nash said.

Auris's treatment could hit peak sales of $250 million, according to Needham & Co analyst Serge Belanger.

To be sure, both competitors have suffered trial setbacks, which forced them to adjust the design of later studies. They increased the number of patients enrolled and tweaked trial endpoints.

Experts are circumspect about declaring a winner.

Dr. Hinrich Staecker, lead investigator on Auris's U.S. tinnitus trial, said it was impossible to tell which company had the leg up until the latest round of research data comes out.

—Natalie Grover and Divya Grover; Editing by David Greising and Sayantani Ghosh.