The goal of this clinical trial is to investigate if paliroden (CIL001) is safe and can help treat cochlear synaptopathy in adult participants 18-75 years of age with normal hearing thresholds and normal cognition who exhibit chronic, constant tinnitus in both ears and have difficulty understanding speech in noisy environments. The main questions it aims to answer are: * Is the study drug safe and tolerable over 6 months after injection into the middle ear? * How much of the study drug is in the bloodstream at different time points after injection? * How effective is a single dose of the study drug at treating cochlear synaptopathy in participants with chronic, constant tinnitus, as measured by hearing and listening tests? Injection of the study drug will be compared to injection of a placebo (a substance with no study drug in it) to see if there is a difference. Participants will be screened for eligibility and potentially receive a one-time injection into the middle ear of paliroden or placebo. The study lasts approximately 6 to 7 months if completing the whole study. Based on the visit windows, this could be between 190 and 218 days including a maximum of 42 days for Screening \& Run-in and 175 days post-treatment. Participants will: * Visit the clinic for checkups and tests multiple times over the course of the study * Complete a large battery of hearing and listening tests, answer questionnaires about their experiences, and provide blood samples for various tests * Receive an injection of either the study drug or placebo (a substance that has no active drug in it), if eligible
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
60
One-time unilateral transtympanic injection of 0.4mL of paliroden (CIL001)
One-time unilateral transtympanic injection of 0.4mL of non-matching placebo
Incidence, nature, and severity of adverse events (AEs) and serious adverse events (SAEs) from baseline to 6 months (168 days). Safety data, including all observed AEs with a particular focus on ear and auditory symptomatology.
Time frame: From baseline to 6 months (168 days) after injection
Determine the concentration in plasma of paliroden with Area under the plasma concentration versus time curve (AUC)
Time frame: From the day of injection to 28 days
Determine the concentration in plasma of paliroden with Peak Plasma Concentration (Cmax)
Time frame: From the day of injection to 28 days
Determine the time to maximum plasma concentration (Tmax).
Time frame: From the day of injection to 28 days
Change from baseline in auditory function using speech-in-noise intelligibility as measured by the English (US) Matrix Test (AE-Matrix) and Time Compressed Words.
For AE-Matrix: Speech level will be fixed at 65 dB HL, while noise level will be adjusted based on responses to determine levels at which participants obtained a speech reception threshold of 50% (in dB). For Time Compressed Words: This test consists of 50 carrier phrase and word stimuli from the Northwestern University Auditory Test No. 6 (NU-6) pool of 200 words that are compressed 60% (i.e., 60% of the carrier phrase and word has been removed). Participants will be asked to repeat the words they hear. Speech will be presented at 55 dB HL. Performance will be assessed by counting the number of words repeated correctly.
Time frame: From baseline to day 28, day 56, day 84, and day 168
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.