Incannex announces positive results from phase 2 clinical trial investigating the effect of IHL-42X for treatment of obstructive sleep apnoea

Highlights:

• IHL-42X reduced primary endpoint apnoea hypopnea index relative to baseline at all three doses that were assessed
• Low dose IHL-42X exhibited superior safety and efficacy metrics to mid and high doses
• Low dose IHL-42X reduced AHI by an average of 50.7% compared to baseline with 25% of participants experiencing a reduction in the apnoea hypopnea index of greater that 80%
• Oxygen desaturation index was reduced by 59.7% relative to baseline while taking low dose IHL-42X, improving sleep quality and reducing cardiovascular stress
• In low dose IHL-42X samples, THC concentrations in blood were well below the limits for impaired driving the morning after dose administration
• IHL-42X was well tolerated – low dose IHL-42X was observed to have a lower number of total treatment emergent adverse events than placebo
• Low dose IHL-42X reduced AHI substantially more effectively than is reported for the component active pharmaceutical ingredients, dronabinol and acetazolamide, as unregistered monotherapies.

MELBOURNE, Australia, June 3, 2022 /PRNewswire/ -- Incannex Healthcare Limited (NASDAQ: IXHL) (ASX: IHL), ('Incannex' or the 'Company') a clinical-stage pharmaceutical company developing unique medicinal cannabinoid pharmaceutical products and psychedelic medicine therapies for unmet medical needs, is pleased to announce that it has completed analysis of data from the phase 2 proof-of-concept clinical trial investigating IHL-42X for treatment of obstructive sleep apnoea ('OSA'). IHL-42X reduced apnoea hypopnoea index ('AHI'), improved patient reported sleep quality and was well tolerated.

The clinical trial assessed three doses of IHL-42X at reducing the AHI in patients who suffered from OSA. Data was also collected for other aspects of sleep quality, THC clearance and safety. Trial participants received each of the three doses of IHL-42X and placebo across four seven-day treatment periods, separated by one week washout periods. At the end of each treatment period, they attended the clinic for an overnight sleep study where AHI was determined, along with other measures of sleep quality, quality of life and drug safety.

The study was conducted at the University of Western Australia Centre for Sleep Science and The Alfred Hospital. A total of eleven participants were recruited to the study and ten participants completed treatment periods. The crossover design of the study permitted Incannex to generate high quality data with a reduced participant number compared to a conventional parallel arm study. Each participant serves as their own internal control and inter-participant variation is eliminated. Data analysis was completed by Novotech, the contract research organisation responsible for management of the study, as well as the Incannex scientific research team, led by Chief Scientific Officer Dr Mark Bleackley. The findings of the clinical trial are presented below.

Effect of IHL-42X on apnoea hypopnoea index (AHI)

AHI is a measure of the number of times per hour a subject's airway is blocked (apnoea) or partially blocked (hypopnoea). It is the main criteria used to diagnose and monitor OSA. AHI data was collected during overnight polysomnography on night seven of the treatment periods.

• All doses of IHL-42X reduced AHI in patients with sleep apnoea compared to baseline (Table 1). This reduction was substantially greater than observed for placebo.
• At the group level the difference relative to baseline with low dose and medium dose was statistically significant (p80% in 25% of subjects (Table 2).
• Low dose IHL-42X reduced AHI to the greatest extent at both the group level and when comparing the within subject reduction relative to baseline
• Low dose IHL-42X reduced AHI to a greater extent than predicted based on published data for dronabinol and acetazolamide alone (Table 3).

The reduction in AHI observed during IHL-42X treatment periods means that when treated with Incannex's proprietary drug, subject's breathing was interrupted less frequently during sleep. This supports Incannex's hypothesis that IHL-42X is an effective treatment for OSA. The observation that low dose IHL-42X was the most effective at reducing AHI is encouraging for the development of IHL-42X as a pharmaceutical as a lower dose will reduce risk of side effects and the cost of goods.

Furthermore, greater reduction in AHI with low dose IHL-42X compared to dronabinol and acetazolamide at equivalent doses supports Incannex's hypothesis that the two drugs are acting synergistically to reduce AHI and provides confidence that IHL-42X will meet the FDA's combination rule where both APIs must contribute to the therapeutic effect of a fixed dose combination product.

Table 1. Average AHI data for baseline and each treatment period

Table 2. Change in AHI from baseline within subject (least square mean)