A Phase II/III, Randomised, Double-Blind Clinical Trial to Determine the Safety and Efficacy of IHL-42X in Subjects With Obstructive Sleep Apnoea Who Are Intolerant, Non-Compliant, or Naïve to Positive Airway Pressure

Inclusion criteria

• 1. Aged ≥18 years of age 2. Screening polysomnography (PSG) findings confirmed on central over-read: 1. AHI ≥15 2. ≤ 25% central or mixed apneas/hypopneas 3. no Cheyne-Stokes respiration 4. total sleep time ≥ 2 hours 3. Intolerant, non-compliant, or naïve to PAP (Note: No more than 25% of the study population will consist of PAP-naïve patients). Patients will be identified as intolerant, non-compliant, or naïve to PAP devices by the following criteria: 1. Patients are regarded as PAP-non-compliant if they do not use PAP for ≥ 4 hours for at least 21 nights during consecutive 30-day period based on data collected from the PAP device (eg, SD storage cards) and/or a cloud-based repository of PAP device data. 2. Patients are regarded as PAP-intolerant if they are former PAP users, ie, a PAP device that they have not used for \>30 days or who do not have access to PAP device 3. Patients are regarded as PAP-naïve if they have no prior experience with PAP. Patients who have undergone a split-study, ie, a study of PAP during PSG, are not considered PAP- naïve and should be categorised according to a through b above. (Note: PAP-naïve patients will have the benefits and risks of PAP explained at screening, including that PAP is standard of care for OSA. These patients also have the option to withdraw from the study at any time if he/she elects to be treated with PAP or other alternative therapy such as an oral appliance or surgery) 4. Must agree not to take any form of cannabis or cannabinoid, or any other illicit or recreational drug with the exception of the investigational product (IP) while participating in this study. 5. A female patient of childbearing potential must agree to use 2 approved methods of contraception. Approved methods of contraception include the following: 1. Intra-uterine device in place for at least 3 months prior to Day 1 through to 10 days following the last dose of the study drug 2. Barrier method (condom or diaphragm) for at least 3 months prior to Day 1 through to 10 days after the last dose of the study drug 3. Stable hormonal contraceptive which includes oral, intravaginal, intrauterine, transdermal, injectable, or implantable methods of hormonal contraception for at least 3 months prior to Day 1. A female will not be considered of childbearing potential if: 1. 12 months of spontaneous amenorrhea or 6 months of spontaneous amenorrhea with serum FSH levels \> 40 mIU/ml 2. undergone bilateral tubal ligation, hysterectomy, or bilateral oophorectomy at least 6 months prior to Day 1 6. A male patient must agree to use at least 1 approved method of contraception (or as required by local regulations) while engaging in sexual activity from study Day -1 through End-of-Study (EOS) follow-up and/or up to 10 days following the last administration of the study drug. Male patients must not donate sperm during this same period. Approved methods of contraception include the following: 1. Barrier method (condom) for at least 14 days prior to Day 1 through to 10 days after the final dose of the study drug 2. Surgical sterilisation (vasectomy) at least 6 months prior to Day 1 7. Voluntarily written consent to participate in the study and be willing and able to participate in all scheduled visits, treatment plans, tests, and other study procedures according to the protocol