• Incannex Healthcare gets US FDA approval to open IND for Pivotal Phase 2/3 trial of IHL-42X into obstructive sleep apnoea (OSA)
  • OSA is the most prevalent sleep-related breathing disorder with no pharmaceutical solution
  • This pivotal trial builds on positive results released in 2022 from Phase 2 proof of concept clinical study, whereby the drug halved the patient’s AHI measure


The US Food and Drug Administration (FDA) has approved Incannex Healthcare’s Investigational New Drug (IND) application for IHL-42X for treatment of obstructive sleep apnoea (OSA), a condition with no registered pharmaceutical treatment.  

Incannex Healthcare (ASX:IHL) is a clinical-stage pharmaceutical company developing proprietary medicinal cannabinoid products and psychedelic assisted psychotherapies “for unmet needs”, including OSA.

Recent phase 2 testing of IHL-42X — made from a synthetic form of tetrahydrocannabinol (THC), and acetazolamide, a carbonic anhydrase inhibitor — reduced average apnoea-hypopnoea index (AHI) by an average of 50.7% versus baseline assessments and 25% of participants experienced greater than an 80% reduction in the AHI.

No serious treatment emergent adverse events were reported during the clinical trial, and THC concentrations in blood were below the limits for impaired driving the morning after nocturnal dose administration.

The company has now received crucial approval from the FDA Administration (FDA) to conduct its Investigational New Drug (IND) opening pivotal IHL-42X Phase 2/3 clinical trial in the US, as planned.

Submitting an IND to the FDA is crucial for companies to gain regulatory approval, conduct clinical trials, and engage in scientific dialogue with FDA whilst they progress investigational drugs through the stages of development in the US.


Sleep apnoea: a multi-billion dollar market

OSA stands as the most prevalent sleep-related breathing disorder, characterised by the narrowing of the upper airway during sleep.

The narrowing hampers proper breathing, leading to reduced oxygen intake and consequently, disrupted sleep quality.

When left untreated, OSA gives rise to severe, long-term negative health outcomes, including hypertension, cardiovascular disease, heart attacks, cognitive decline, anxiety, depression, irritability, and daytime fatigue, heightening the risk of accidents.

Despite the prevalence of this condition, there are currently no available pharmaceutical treatments for OSA.

The established treatment approach centres around the use of a Continuous Positive Airway Pressure (CPAP) machine. However, patient adherence to CPAP is frequently compromised due to various discomfort-related factors.

The global market for sleep apnoea devices is poised to attain a value of $US12.88 billion by 2030 with a CAGR of 6.9%, for which IHL could tap into through its pharmaceutical solution.


Assessing effect of IHL-42X on OSA patients

The IND opening trial will assess the effect of IHL-42X in OSA patients who are non-compliant, intolerant, or naïve to positive airway pressure treatment, such as that administered by CPAP devices.

IHL says it will continue the start-up process for the Phase 2/3 clinical trial, including finalisation of institutional review board (IRB) applications and submissions for the lead clinical trial sites.

Site selection, approvals, and IRB submission for additional study sites swill continue in parallel.

In the IND opening Phase 2/3 clinical trial, participants will receive one dose of IHL-42X, dronabinol, acetazolamide or placebo for the entirety of the trial.

All participants will complete daily surveys on their sleep quality, attend monthly clinic visits to assess functional outcomes of sleep, cognitive function and other measures of safety and efficacy.

Every three months, overnight polysomnography will be conducted to determine the effect of treatment on the patients’ Apnea Hypopnea Index (AHI) along with a range of other sleep parameters. All drug treatments will be compared to placebo.

When announcing submission of the IND application, IHL announced it had partnered with Fortrea (NASDAQ: FTRE) as the chosen contract research organization (CRO) responsible for overseeing the opening of Phase 2/3 clinical trials.

Leveraging its wealth of valuable data sets and technology-driven clinical trial solutions, Fortrea aims to enhance study recruitment, diminish study-associated risks, ensure data quality, and gather operational insights as the trial advances.


This article was developed in collaboration with Incannex Healthcare, a Stockhead advertiser at the time of publishing.  

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.