Incannex Healthcare Announces Positive Topline Results From Pharmacokinetics Study of an Oral Combination Medicine for the Treatment of Obstructive Sleep Apnea

Incannex Healthcare Inc. recently announced positive topline results from a completed pharmacokinetics (PK) and safety study of IHL-42X, a novel, oral fixed-dose combination of acetazolamide and dronabinol for the treatment of Obstructive Sleep Apnea (OSA).

“The topline IHL-42X PK findings we are reporting today provide data necessary to support a 505(b)(2) application in accordance with FDA guidance, assuming continued positive results from our Phase 2 and 3 clinical trials,” said Mark Bleackley, PhD, Incannex’s Chief Scientific Officer. “The trial results are consistent with our expectations and the objectives for IHL-42X, a novel, oral fixed-dose combination therapeutic.”

The study confirmed bioavailability of IHL-42X, demonstrating delivery of both dronabinol and acetazolamide. The PK profile of IHL-42X was similar to those observed for the respective RLDs, including equivalent total exposure levels observed for the drug molecules. Furthermore, administration of IHL-42X with food, in contrast to fasted conditions, indicated no substantial food effect on overall exposure to acetazolamide. Consistent with what is known for the RLD, an increase in overall exposure to THC was observed when IHL-42X was administered with food compared to fasted state. No serious adverse events were reported during the study. All but one Treatment-Emergent Adverse Event (TEAE) was reported to be mild or moderate. The proportion of subjects reporting at least one TEAE on the IHL-42X fasted period (57.4%) was similar to the dronabinol fasted period (52.1%). Fewer subjects reported TEAEs during the acetazolamide fasted treatment period (37.8%). Food did not have a substantial effect on the number of subjects reporting TEAEs for IHL-42X, with 57.4% fasted vs 58.8% fed.

This data establishes a scientific bridge to the reference listed drugs (RLD), potentially enabling the Company to leverage existing safety and toxicology data in a FDA 505(b)2 new drug application for IHL-42X, and assist in the analysis of the global Phase 2/3 RePOSA trial.

The study was designed to assess the safety and pharmacokinetics of IHL-42X, a novel combination formulation, as compared to its respective FDA reference listed drugs. Conducted as a randomized, four-period crossover study in healthy volunteers at two sites in Australia, the trial involved 125 participants, 114 of whom completed all treatment periods. Each treatment period involved the administration of one of four regimens: IHL-42X (dronabinol 5 mg, acetazolamide 250 mg) in fasted or fed state, dronabinol (5 mg) in a fasted state, or acetazolamide (250 mg) in a fasted state. Subjects were assigned to one of four sequences, with each sequence following a distinct order.

IHL-42X, an oral fixed-dose combination of acetazolamide and dronabinol, is currently in Phase 2/3 clinical studies for the treatment of obstructive sleep apnea (OSA). Designed to act synergistically, IHL-42X targets two different physiological pathways associated with the intermittent hypoxia (IH) and hypercapnia that characterize OSA. In a prior Australian Phase 2 clinical trial, IHL-42X was shown to reduce the Apnea-Hypopnea Index (AHI) in all dosage strengths, with the lowest dose reducing AHI by an average of 51 percent relative to baseline. RePOSA, a global Phase 2/3 clinical trial is underway, evaluating IHL-42X in individuals with OSA who are either non-compliant, intolerant, or naïve to positive airway pressure devices, including CPAP, with the Phase 2 portion conducted in the United States. The expanded Phase 3 portion will include sites in the United Kingdom and European Union. A topline readout from the U.S. Phase 2 portion is anticipated in the first half of 2025.

Incannex is leading the way in developing combination medicines that target the underlying biological pathways associated with chronic conditions, including obstructive sleep apnea, rheumatoid arthritis and generalized anxiety disorder. The company is advancing novel oral fix-dosed treatments and therapeutic regimens based on evidence-based innovation. Incannex’s lead Phase 2/3 and Phase 2 clinical programs include IHL-42X, an oral fixed-dose combination of dronabinol and acetazolamide, designed to act synergistically in the treatment of OSA for the treatment of obstructive sleep apnea; IHL-675A, an oral fixed-dose combination of cannabidiol and hydroxychloroquine sulfate, acting synergistically to alleviate inflammation, and PSX-001, an oral synthetic psilocybin treatment in combination with psychotherapy, for the treatment of generalized anxiety disorder. Incannex’s programs target disorders that have limited, inadequate, or no approved pharmaceutical treatment options.