A Study Testing the Safety and Possible Benefits of an Ear Injection of a New Compound, Paliroden, in People With Type 2 Diabetes Who Have Difficulty Understanding Speech in Noisy Situations

A Randomized, Double-blind, Placebo-controlled, Ascending Volume Phase 1B/2A Clinical Trial to Investigate the Safety and Efficacy of a Single Transtympanic Injection of CIL001 (Paliroden) for the Treatment of Cochlear Synaptopathy in Participants With type2 Diabetes

Like retinopathy, neuropathy and nephropathy, sensorineural hearing loss is a common and underserved complication of uncontrolled diabetes. Neuroinflammation in diabetes can cause auditory nerve damage (cochlear synaptopathy) which first translates into speech-in-noise intelligibility deficit. CIL001 is a neurotrophic small molecule that aims to repair auditory nerve when applied locally by transtympanic injection. Transtympanic injection of paliroden is anticipated to improve the symptoms of cochlear synaptopathy. Furthermore, by addressing auditory or vestibular dysfunction early and effectively, this approach may contribute to limiting or delaying, over the long term, the onset of secondary neurological disorders, such as dementia.

Inclusion Criteria:

1. Signed and dated informed consent form

2. Aged between 45 and 75 years old (inclusive) at the time of screening

3. Established type 2 diabetes as determined by 7% ≤ hemoglobin A1c (HbA1c) ≤ 9% and diabetes duration of at least 5 years

4. Be considered as reliable and capable of adhering to the protocol, according to the judgment of the Investigator

5. Participants must be native speakers of the official language(s) of the country in which the study assessments are conducted.

6. Women of childbearing potential (WOCBP) must have a negative serum pregnancy test upon entry into this study. In addition, they must agree to use highly effective contraception methods, as defined by regulatory guidance (e.g., combined hormonal contraception, intrauterine device, or surgical sterilization), from the screening visit, for the duration of study treatment and for 30 days after dosing.

   The following audiology assessments, if not performed on the same day as the review of the previous criteria (e.g., when the participant's first visit does not take place at the ENT site), may be scheduled on different days within a maximum interval of 14 days after the first screening visit and must be completed at least 21 days before the baseline visit.

7. Normal hearing as defined by PTAv (0.5-1-2kHz-4Khz) <25dB in both ears.

8. Up to mild hearing loss in the high-frequency range (PTAvHF (4-6-8kHz) <40dB) in both ears.

9. Speech-in-noise deficit (at least 3dB SNR loss in comparison to normative value of the Matrix test) in both ears.

Exclusion Criteria:

1. MoCA score < 26

2. Known otologic pathology (e.g., History of autoimmune hearing loss, radiation-induced hearing loss, fluctuating hearing, endolymphatic hydrops, or Menière's disease in either ear)

3. Presence of middle ear pathology (e.g., otitis media, tympanic membrane perforation, etc.)

4. History of platinum-based chemotherapy

5. Previous or concurrent malignancies that require treatment and are not clinically stable

6. Current evidence or history of retrocochlear pathology (e.g., acoustic neuroma)

7. History of otologic surgery (apart from tympanostomy tube insertion if more than one year prior to inclusion visit)

8. Abnormal otoscopy as defined by less than 90% of the tympanic membrane visible (e.g., cerumen ear plug, ear drum perforation). In case of cerumen plugs not affecting the hearing results, a removal must be scheduled before V1 (baseline/inclusion).

9. Hearing aids and cochlear implants.

10. History of cancer treated by platinum-based chemotherapy.

11. Lactation or known pregnancy or positive pregnancy test at both screening and baseline for women of childbearing potential, or planning to become pregnant during the study

12. Liver Enzyme Lab Outcomes:

    1. Bilirubin > 2 times the upper limit of normal (ULN)
    2. Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) (AST/ALT) >5 times ULN.
    3. Gamma glutamyltransferase (GGT) > 5 times ULN

13. Maternally Inherited Diabetes

14. Congenital hearing loss

15. Untreated hypothyroidism

16. Adult individual under legal protection as defined by applicable regulations (e.g., persons deprived of liberty, hospitalized without consent, unable to provide informed consent, or placed under legal guardianship or curatorship)

17. Concurrent participation in another clinical study or participation in another trial involving experimental drug within 30 days or five half-lives of the experimental drug (whichever was longer) prior to screening visit (V0).

18. Diagnosed anxiety disorders, psychosis, depression, schizophrenia, attempted suicide, or other significant psychiatric conditions that could impact their ability to cooperate and comply with the study protocol

19. Major surgery that may impact the study conduct or outcomes within eight weeks before screening or scheduled/planned surgery within the time frame of the study