Frequency Therapeutics is making even more progress with their development of FX-322, a drug candidate in clinical trials to potentially restore acquired sensorineural hearing loss. The company has now completed enrollment of its phase 2b study of the drug candidate, and plans to release study data in the first quarter of 2023.
The large phase 2b study is designed to look at efficacy and safety, and includes a broad number of secondary outcome measures. “The study is powered to detect a statistically significant (p<0.05) difference between FX-322 and placebo subject groups,” Carl LeBel, PhD, Frequency’s Chief Development Officer. P<0.05 means there is less than a 5 percent chance that the changes aren’t real. If this study goes well, the next step is phase 3 trials. “Assuming we have positive data, we would meet again with the FDA and file for Breakthrough Therapy designation,” says Dr. LeBel. Breakthrough Therapy designation is designed to expedite the development and review of drugs that demonstrate substantial improvement over existing therapies. Of course, there are currently no drug therapies available to improve hearing loss, so this would be the first of its kind.
More Participants, More Hearing Gains
The phase 2b study has enrolled 142 individuals at 28 different clinical sites throughout the U.S. The participants are adults between 18-65 years old who have either noise-induced or permanent idiopathic sudden hearing loss, which are considered “acquired” hearing loss. “Our study population are people who’ve had a cochlea that was working well, that stops working well because of some force on it, such as noise or other external factors,” says Kevin Franck, PhD, Senior Vice President of Strategic Marketing and New Product Planning.
Due to what the company has learned from previous trials, the study population is also comprised of people with higher mild to lower severe hearing loss range, as they seem to respond best to the drug candidate. Improvement response is focused on better speech perception. With improved speech perception, individuals may hear words more clearly, a critical unmet need for individuals with hearing loss.
Measuring Improvement of FX-322
First, the study group is divided into people who will get a placebo, and those who will get FX-322. FX-322 participants get a single injection of the drug in their middle ear. Ninety days after, they undergo a speech perception test, which people with hearing loss do routinely when they are examined by an audiologist. A list of 50 words is read out loud, and the person has to repeat them back.
Although a 10 percent improvement is considered clinically meaningful, Frequency is also looking for what is statistically significant. So, while an extra 5 correct words would be a 10 percent improvement, “Some of the differences we’re seeing are actually twenty words out of fifty,” which is quadruple that, says Dr. Franck. To be deemed successful, a statistically significant (p<0.05) percent more of the participants treated with FX-322 have to show clear improvements in their speech perception compared to the placebo group.
The drug also seems to be well-tolerated in participants. “The beauty of doing local delivery to the ear is you don’t have to worry about systemic side effects,” says LeBel. The drug gets straight into the cochlea, and while people who receive it may feel a sense of fullness in their ear, the discomfort is mild and temporary, with no lasting side effects observed. “That’s really important for therapy of this nature,” LeBel adds.
Looking to the Future
The team has learned a lot from their previous trials of the drug, and the possibility that FX-322 will be available on the market in the not-too-distant future draws closer. “We feel confident that we’ve designed a study in the best way possible to be able to demonstrate very clearly that FX-322 can provide a benefit in hearing loss,” says LeBel. “We really can’t wait to see the results.”
More to come in early 2023 when the study results are published.