The trial will assess the safety and efficacy of IHL-42X, a fixed-dose combination of dronabinol and acetazolamide, in patients with obstructive sleep apnea.

Summary: Incannex Healthcare Inc, a pharmaceutical company focused on developing medicinal cannabinoid pharmacotherapies and psychedelic medicine therapies, has commenced patient dosing in its phase 2/3 clinical trial to evaluate the safety and efficacy of IHL-42X for treating obstructive sleep apnea (OSA). IHL-42X is a proprietary fixed-dose combination of dronabinol and acetazolamide. This trial, known as the RePOSA study, follows an Investigational New Drug (IND) application with the US FDA and a successful phase 2A study showing significant reductions in the apnea-hypopnea index (AHI). The RePOSA study will involve up to 560 patients across multiple sites in the US, EU, and UK, with a seamless transition from phase 2 to phase 3.

Key Takeaways:

Patient Dosing Initiated: Incannex Healthcare has started patient dosing in the phase 2/3 RePOSA clinical trial, aiming to assess the safety and efficacy of IHL-42X, a combination of dronabinol and acetazolamide, for treating obstructive sleep apnea.
Preliminary Results: Previous phase 2A studies showed that IHL-42X could reduce the apnea-hypopnea index (AHI) by over 50% in patients, with 25% of participants experiencing a reduction in AHI greater than 80%.
Clinical Trial: The RePOSA study will enroll at least 560 patients across 55 sites in the US, EU, and UK. It includes a four-week phase 2 dose-ranging trial and a 52-week phase 3 factorial trial to determine the optimal dose and long-term efficacy of IHL-42X.

Incannex Healthcare Inc, a pharmaceutical company developing medicinal cannabinoid pharmacotherapies and psychedelic medicine therapies, announced that patient dosing has commenced in the company’s phase 2/3 clinical trial to assess safety and efficacy of IHL-42X in patients with obstructive sleep apnea (OSA).

IHL-42X is the company’s proprietary fixed-dose combination drug for the treatment of OSA. IHL-42x is comprised of dronabinol, a synthetic form of tetrahydrocannabinol, and acetazolamide, a carbonic anhydrase inhibitor. Initiating dosing in the trial follows the opening of an Investigational New Drug (IND) application with the US Food and Drug Administration and a phase 2A study completed in 2022 whereby Incannex observed IHL-42X to reduce the apnea-hypopnea index (AHI) by an average of greater than 50% at the low dose in the study.

Furthermore, 25% of patients experienced a reduction in AHI of greater than 80%, representing a sub-clinical AHI score for some trial participants.

“Patient dosing in the RePOSA study represents a critical step forward in the development of IHL-42X for treatment of obstructive sleep apnea,” says Mark Bleackley, PhD, Incannex chief scientific officer, in a release. “There are currently no registered pharmacotherapies available to patients and poor compliance to positive airway pressure devices means that many patients with sleep apnea are left untreated or chronically under-treated. IHL-42X has the potential to address this unmet need, improving the direct effects of sleep apnea, as well as the associated long-term health and quality of life impacts on this patient population. We look forward to working with trial sites and investigators to continue to recruit and dose patients in the RePOSA trial.”

The RePOSA Clinical Trial

The RePOSA study is a phase 2/3, randomized, double-blind clinical trial to determine the safety and efficacy of IHL-42X in subjects with OSA who are intolerant, non-compliant, or naïve to positive airway pressure, such as that administered via a continuous positive airway pressure machine.

The RePOSA study consists of two component studies. A four-week phase 2 dose-ranging trial will determine the optimal dose of IHL-42X based on safety and efficacy in OSA patients, and a 52-week phase 3 factorial trial will compare the optimal dose of IHL-42X to the component APIs, dronabinol, and acetazolamide, at equivalent doses, as well as placebo. The trial is designed to facilitate a seamless transition between phase 2 and phase 3, intended to reduce downtime, accelerating time to commercial product development.

The endpoints, inclusion criteria, and study procedures are the same across both component studies, streamlining the transition from phase 2 to phase 3. The target patient population is individuals aged 18 years or older with OSA who are intolerant, non-compliant, or naïve to positive airway pressure.

At least 560 patients will be recruited, with a total of 355 patients receiving IHL-42X over the course of the study. Phase 2 of the RePOSA study will be conducted at 25 sites in the United States. Phase 3 will extend the study to 30 additional sites across the EU and UK.