Faculty Collaboration Database

Improved Speech Intelligibility in Subjects With Stable Sensorineural Hearing Loss Following Intratympanic Dosing of FX-322 in a Phase 1b Study. Otol Neurotol 2021 Aug 01;42(7):e849-e857

Date

02/23/2021

Pubmed ID

33617194

Pubmed Central ID

PMC8279894

DOI

10.1097/MAO.0000000000003120

Scopus ID

2-s2.0-85107730392 (requires institutional sign-in at Scopus site)   28 Citations

Abstract

OBJECTIVES: There are no approved pharmacologic therapies for chronic sensorineural hearing loss (SNHL). The combination of CHIR99021+valproic acid (CV, FX-322) has been shown to regenerate mammalian cochlear hair cells ex vivo. The objectives were to characterize the cochlear pharmacokinetic profile of CV in guinea pigs, then measure FX-322 in human perilymph samples, and finally assess safety and audiometric effects of FX-322 in humans with chronic SNHL.

STUDY DESIGNS: Middle ear residence, cochlear distribution, and elimination profiles of FX-322 were assessed in guinea pigs. Human perilymph sampling following intratympanic FX-322 dosing was performed in an open-label study in cochlear implant subjects. Unilateral intratympanic FX-322 was assessed in a Phase 1b prospective, randomized, double-blinded, placebo-controlled clinical trial.

SETTING: Three private otolaryngology practices in the US.

PATIENTS: Individuals diagnosed with mild to moderately severe chronic SNHL (≤70 dB standard pure-tone average) in one or both ears that was stable for ≥6 months, medical histories consistent with noise-induced or idiopathic sudden SNHL, and no significant vestibular symptoms.

INTERVENTIONS: Intratympanic FX-322.

MAIN OUTCOME MEASURES: Pharmacokinetics of FX-322 in perilymph and safety and audiometric effects.

RESULTS: After intratympanic delivery in guinea pigs and humans, FX-322 levels in the cochlear extended high-frequency region were observed and projected to be pharmacologically active in humans. A single dose of FX-322 in SNHL subjects was well tolerated with mild, transient treatment-related adverse events (n = 15 FX-322 vs 8 placebo). Of the six patients treated with FX-322 who had baseline word recognition in quiet scores below 90%, four showed clinically meaningful improvements (absolute word recognition improved 18-42%, exceeding the 95% confidence interval determined by previously published criteria). No significant changes in placebo-injected ears were observed. At the group level, FX-322 subjects outperformed placebo group in word recognition in quiet when averaged across all time points, with a mean improvement from baseline of 18.9% (p = 0.029). For words in noise, the treated group showed a mean 1.3 dB signal-to-noise ratio improvement (p = 0.012) relative to their baseline scores while placebo-treated subjects did not (-0.21 dB, p = 0.71).

CONCLUSIONS: Delivery of FX-322 to the extended high-frequency region of the cochlea is well tolerated and enhances speech recognition performance in multiple subjects with stable chronic hearing loss.

Author List

McLean WJ, Hinton AS, Herby JTJ, Salt AN, Hartsock JJ, Wilson S, Lucchino DL, Lenarz T, Warnecke A, Prenzler N, Schmitt H, King S, Jackson LE, Rosenbloom J, Atiee G, Bear M, Runge CL, Gifford RH, Rauch SD, Lee DJ, Langer R, Karp JM, Loose C, LeBel C

Author

Christina Runge PhD Associate Provost, Chief, Professor in the Otolaryngology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Guinea Pigs
Hearing Loss, Sensorineural
Hearing Loss, Sudden
Humans
Prospective Studies
Speech Intelligibility
Speech Perception
Treatment Outcome