Chris Sopuch has taught at Oakcrest High School in New Jersey for 25 years. But in 2017, Sopuch was almost forced to walk away from his life's work at the age of 48.
"I woke up Jan. 5 to realize I could not hear properly out of my left ear," he told CBS News.
Immediately, Sopuch knew something was wrong.
"When I first awoke that morning, the sound that I heard was robotic because I was still hearing sounds, and it was like a screeching sound," he said.
Sopuch was diagnosed with sudden hearing loss. Doctors told him there was nothing they could do.
"There's no way to fix that," Sopuch said he was told.
Traditional methods like hearing aids were not guaranteed to help in his case. Steroids didn't work, either. And there isn't a drug on the market to restore hearing.
"I was just trying to get by from day to day," he said. "I was not happy at all."
Then Sopuch learned about a biotech company called Frequency Therapeutics. The company advertised a clinical trial for an early-stage drug being tested to treat sudden hearing loss.
"This is for people who are born with healthy hearing, and over time, because of noise pollution — that their hearing, you know, really declines," said company founder and CEO David Lucchino.
The treatment involves giving patients a single shot inside their ear. Lucchino said the injection, called FX-322, can help restore hearing by activating so-called "sleeping" cells to make up for the ones damaged by things like aging, infections or loud noises.
"Five minutes in the ENT (ear, nose and throat) office and then they'll give you a few minutes just to make sure you're recovered and feeling good, and then you're on your way," Lucchino said.
So Sopuch flew to San Antonio for a trial about 18 months after losing his hearing. A month later, while traveling for a checkup, he had a breakthrough.
"Everything just came back in life, like all of a sudden, like a light switch," he said.
At the time, Dr. Steven Eliades was overseeing Sopuch's care at the University of Pennsylvania. He said Sopuch had "great improvement" that he attributes to the drug.
"I don't have a better explanation for things," Eliades said. But he added, "It's still too early to tell."
Frequency Therapeutics says 11% of study participants had statistically significant responses to the drug over the course of four trials.
But in a different multi-dose trial last year, participants showed no reliable improvement. That led to the company's stock plummeting. Some investors even sued.
Frequency told CBS News they can't comment on the lawsuits, but says the data was unreliable due to how participants were screened — not due to the drug itself. The company is aiming to release data from its latest clinical trial in the first quarter of next year. It is planning to get FX-322 to market in the next few years, pending FDA approval of the drug.
Lucchino has a response for those who may be skeptical: "Stand by and watch us, you know, the scientific data will tell the story."
Spouch said losing his hearing was unimaginable, but getting it back has never sounded better.
"I'm at 84%, but I'm basically back to life the way it was before," he said.
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