On March 23, 2021, the Company announced topline, day-90 data from its
FX-322 Phase 2a study. The interim results show that four weekly injections in subjects with mild to moderately severe sensorineural hearing loss (SNHL) did not demonstrate improvements in hearing
measures versus placebo. No treatment-related serious adverse events were observed in the study. The Company also announced new data from a parallel study demonstrating hearing improvement from a single injection of
FX-322. The Company plans to advance further development of FX-322 as a single dose regimen.
In the four-arm Phase 2a study, 95 subjects aged 18-65 were evaluated for
hearing improvement using Word Recognition (WR), Words-In-Noise (WIN), pure tone audiometry and additional exploratory measures. All subjects
were administered a total of four weekly intratympanic injections comprised of zero, one, two, or four doses of FX-322 with the balance of injections comprised of placebo doses.
While WR scores increased across all groups, repeated weekly injections appeared to dampen the hearing benefit observed compared to other single
injection-studies. The Phase 2a interim results also showed an unexpected apparent level of hearing benefit in the placebo group that did not occur in previous trials and exceeded well-established published standards, potentially suggesting bias due
to trial design. Given these challenges observed in the Phase 2a study design, there was no discernible hearing benefit of FX-322 over placebo. The Company plans to report final results of the study in late Q2
2021.
The Company also announced preliminary results from a recently completed open-label, single-dose study of
FX-322 designed to evaluate the impact of injection conditions on tolerability. In the multi-center, randomized study, subjects with mild to severe SNHL (n=33) were injected in one ear with FX-322 with the untreated ear as the control. Hearing function was tested over the course of 90 days following dosing.
At day 90 following dosing, thirty-four percent (34%) of subjects achieved a ten percent (10%) or greater absolute improvement in WR scores in the treated
ear, which was clinically meaningful and statistically significant compared to the untreated ear (p <0.05). This included a subset of subjects that more than doubled their WR scores. The single dose had a favorable safety profile and was well
tolerated. These latest results are supportive of the data reported in the prior single dose Phase 1/2 study, recently published in the peer-reviewed journal Otology & Neurotology.
Clinical development activities are ongoing to evaluate FX-322s clinical profile in patients with age-related hearing loss (ARHL) and severe SNHL, to identify additional patient populations that may benefit from this potentially restorative therapeutic approach.
This includes a double-blind, placebo-controlled Phase 1b study of subjects with ARHL (ages 66-85), which is fully
enrolled with 30 subjects. The primary objectives of the Phase 1b ARHL study are to assess the local and systemic safety of a single dose of FX-322 and evaluate hearing responses in an older adult cohort.
Study participants were randomized 4:1 to receive either FX-322 or placebo in one ear. Validated measures of hearing including WR, WIN and pure tone audiometry were used. Safety, otologic and audiologic
assessments were conducted at days 30 and 90 following administration of FX-322 or placebo. The Company expects to share results from this study in Q2 2021.
The Company is also conducting an FX-322 Phase 1b study of up to 30 subjects ages
18-65 with severe SNHL. This study, which has a similar study design as the ARHL study, is continuing to enroll subjects and results are anticipated in Q3 2021.