Incannex Healthcare receives FDA clearance to start IHL-42X clinical trial on patients with obstructive sleep apnoea

Clinical-stage pharmaceutical company Incannex Healthcare (ASX: IHL) has received approval from the US Food and Drug Administration (FDA) to conduct an investigational new drug (IND) opening trial for lead candidate IHL-42X in the US.

The pivotal Phase 2/3 trial will assess the effect of IHL-42X in obstructive sleep apnoea (OSA) patients who are non-compliant, intolerant or naïve to positive airway pressure treatment, such as that administered by CPAP (continuous positive airway pressure) devices.

It has been deemed safe to proceed following the FDA’s assessment of the trial protocol, lead trial investigators and a risk benefit analysis of the trial and prospective product.

Incannex is continuing preparations for the trial’s start-up process which includes finalisation of institutional review board (IRB) applications and submissions for lead clinical trial sites.

Site selection, approvals and IRB submission for additional study sites will be conducted at the same time.

Synergistic combination

IHL-42X is a synergistic composition of dronabinol (a synthetic form of tetrahydrocannabinol (THC) and acetazolamide (a carbonic anhydrase inhibitor).

Participants in the Phase 2/3 trial will receive one dose of IHL-42X, dronabinol, acetazolamide or placebo for the entirety of the trial.

They will complete daily surveys on their sleep quality; and 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’ apnoea hypopnea index (AHI) along with a range of other sleep parameters.

All drug treatments will be compared to placebo.

Concept trial

Results from a Phase 2 proof of concept clinical trial by Incannex were released last year and found that the drug reduced patient AHI by an average of 50.7% versus baseline assessments, with 25% of participants experiencing a reduction of more than 80%.

No serious adverse events were reported during the trial.

Most common disorder

OSA is the most common of all sleep-related breathing disorders.

It involves the narrowing of the upper airway during sleep, interfering with a person’s breathing, decreasing oxygen uptake and resulting in poor-quality sleep.

Untreated OSA can lead to serious long-term adverse health outcomes including hypertension, cardiovascular disease, heart attack, cognitive impairments, anxiety and depression, irritability and daytime fatigue increasing the risk of accidents.

There are no pharmacotherapy (drug) treatments available to those afflicted.

Incannex said it expected “greatly improved treatment compliance” and outcomes for OSA patients from a pharmaceutical product such as IHL-42X.