Envoy Medical and Mayo Clinic are starting a feasibility study of an implantable device for patients with significant hearing loss.

White Bear Lake-based Envoy is developing the Acclaim cochlear implant. Unlike a typical cochlear implant that requires users to wear an external sound processor behind the ear, Envoy's would be the first such device to be fully implanted in the ear — if approved by the U.S. Food and Drug Administration.

Cochlear implants are for people with severe hearing loss who can't be helped by hearing aids.

Mayo's undertaking is not a full clinical trial; it is defined by the FDA as an early feasibility study, which calls for only a small number of patients to participate. This Acclaim study will have just three patients.

"People don't like the external components," said Dr. Colin Driscoll, a Mayo Clinic otolaryngologist specializing in head and neck surgery, who will be the study's principal investigator. He said patients with standard cochlear implants have difficulty sleeping or showering.

"A fully implantable device really does give you the opportunity of 24/7 hearing," said Driscoll. "There's no other fully implantable device [available] in the United States."

Now that Envoy has an "investigational device exemption" from the FDA, Mayo can start recruiting patients. Envoy will later need to complete a pivotal clinical trial to secure FDA approval.

The study will follow the patients for 12 months.

In 2019, Envoy received the FDA's "Breakthrough Device" designation for the Acclaim. This gives the company more direct contact with regulators and can help expedite the approval process.

Envoy, founded in 1995, is a small company with about 25 employees. Its implantable Esteem device has been available in the U.S. since 2010.

CEO Brent Lucas originally joined Envoy as an intern in 2007. After graduating law school, he became general counsel in 2009 and has held the top post since 2015.

His father, Roger Lucas, was one of Envoy's initial shareholders and a former board chair. The senior Lucas previously cofounded Techne Corp., which — through a series of acquisitions — became what is today known as Bio-Techne Corp.

Envoy's Esteem device has faced challenges.

"The Esteem has had trouble to gain commercial traction," Lucas said. "It is not covered by Medicare and Medicaid, and it is not robustly covered by commercial insurers."

That's largely because the Centers for Medicare & Medicaid Services classifies Esteem as a hearing aid, which is not covered by those federal programs. Cochlear implants, however, are covered, Lucas said.

He said the commercialization of Acclaim is a few years away but possible in the "mid-2020s." An estimated 1.8 million Americans have severe hearing loss.

Glen Taylor, owner of the Star Tribune, is an Envoy investor.

This story has been updated with Roger Lucas' titles and positions at Envoy and Techne Corp.