A Double-Blinded, Placebo-Controlled, Randomized, Phase 1/2a Clinical Study to Test the Safety and Efficacy of a Treatment for a Form of Age-Related Central Auditory Processing Disorder Consisting of Clemastine Fumarate Plus Engineered Sound
The goal of this clinical trial is to determine the efficacy of Clemastine Fumarate in the presence of engineered sound to treat age-related central auditory processing disorder (CAPD). This disorder impacts 800M patients worldwide, including \ 1/3 people over 40 years of age and \ 1/2 people over 65, resulting in an inability to hear in noisy environments. The primary hypothesis this study aims to test is: engineered sound, driving localized neural circuit activity, will enable Clemastine Fumarate to mature Oligodendrocyte cells and thus remyelinate these activated neural circuits. This Localized Oligodendrocyte Optimization Therapy (LOOT) was highly effective in preclinical animal studies so this clinical trial aims to answer if this therapy will translate to humans. The study is an adaptive design intended to compare the efficacy of the drug in the presence or absence of the engineered sound for improving hearing in noise ability. Trial participants will be tested for hearing thresholds and ability to isolate a sound signal from background noise. If they meet the inclusion criteria, they will be enrolled into one of the four arms of the study and undergo the proposed one-month treatment (drug and sound or respective placebos). After the treatment period, trial participants will be tested again for hearing thresholds and their ability to isolate s sound source of interest from background noise. The hypothesis to be tested in this clinical trial is that the one-month treatment will significantly improve the participant's ability to isolate a sound source of interest from background noise. The design has four arms, drug+sound, placebo+sound, drug+white noise, and placebo+white noise. Based on our preclinical data, control arms are all expected to show identical results, thus our adaptive design includes interim analyses to allow for dropping of two of the three placebo arms should the preclinical results be replicated as anticipated. We will also monitor each participant's general health during the duration of the clinical trial, which will be done by performing a number of blood tests, an EKG and a general physical before and after the one-month treatment period. We expect no significant changes since participants will take the drug for the one-month period at dosages already demonstrated safe in several Phase II studies of multiple sclerosis. Similarly, the engineered sound will be listened to for one hour per day during this month at sound intensities well below threshold that might cause noise-induced hearing damage.
• Male or female between 45 and 65 years old (middle aged) at the screening/enrollment visit (Visit 1).
• Written informed consent obtained from the subject and ability for the subject to comply with the requirements of the study.
• Documentation of no more than a mild high-frequency hearing sensitivity loss and normal middle-ear function will be obtained using standard audiometric equipment with measurements done by an audiologist; Specifically, testing will show:
‣ bilateral hearing thresholds \< 20 dB HL at audiometric frequencies from 250 Hz to 4000 Hz inclusively, with no air-bone gaps \> 10 dB.
⁃ symmetrical hearing thresholds between the ears through 8000 Hz, defined as \<20 dB difference at any single audiometric frequency or \< 15 dB difference at 2 or more contiguous frequencies.
⁃ normal (Type A) tympanograms bilaterally.
• No cognitive deficit shown upon screening with the Montreal Cognitive Assessment (MOCA) test (Nasreddine et al. 2005).
• Distortion product otoacoustic emission (DPOAE) showing no more than 20 dB hearing loss at audiometric frequencies from 250 Hz to 4000 Hz.
• Subjects failing the hearing in noise test at 15 degrees. Failing is defined as SNR being 12 dB below from what is found in normal hearing subjects without central hearing loss.