Incannex commences Phase 2 trial of IHL-675A for treatment of pain in RA

Incannex Healthcare commenced a Phase 2 clinical trial to assess the safety and efficacy of its proprietary anti-inflammatory combination drug IHL-675A in patients with rheumatoid arthritis. IHL-675A is a proprietary fixed dose combination drug comprising cannabidiol and hydroxychloroquine. This Phase 2 clinical trial follows the successful Phase 1 clinical trial whereby IHL-675A was observed to be well tolerated, with no adverse events of concern. Prior to commencing clinical trials, Incannex observed positive results from an animal model of RA. IHL-675A was observed to be more effective than a standard dose of HCQ at reducing arthritis across multiple assessments including; clinical score, paw volume, pannus score, total histology score and serum cytokine levels than the rodent equivalent of a standard dose of HCQ, or equivalent dose of CBD. The reduction in disease assessments achieved by IHL-675A were 1.06-3.52 times that observed for HCQ alone at the standard dose. These promising observations led the Company to prioritise rapid clinical assessment of IHL-675A, particularly given that HCQ, marketed as Plaquenil and generic equivalents, is a common long-standing treatment prescribed for RA. The Phase 2 trial now commenced will assess the efficacy, safety and tolerability of IHL-675A compared to the respective component Active Pharmaceutical Ingredients, CBD and HCQ, and placebo. The treatments will be double blinded, meaning neither the investigators nor patients will know which treatment an individual is receiving. The trial will be managed by Avance Clinical, an Australian and US CRO, who will identify and onboard 8-10 clinical trial sites with expertise in RA to conduct patient recruitment and assessments. Avance will manage the sites and study conduct, ensure that the data is of necessary quality and undertake analysis of data collected across all trial sites. The Phase 2 trial will include 120 participants who meet the eligibility criteria. Participants will be randomised to one of four arms: either IHL-675A, CBD alone, HCQ alone or placebo. The primary endpoint of the trial is pain and function, relative to baseline, determined via the score on the RAPID3 assessment at 24 weeks. Participants will also record their pain and function outcomes daily, by completing questionnaires on pain, fatigue, joint stiffness and quality of life, using an electronic Patient Reported Outcomes device. The trial participants will attend monthly visits at the clinical trial site, where blood tests, and physical examinations will monitor additional safety and efficacy outcomes including inflammatory biomarkers. The trial will also include a sub-study examining joint damage via magnetic resonance imaging. Subjects will be assessed for eligibility in the MRI study based on their Rheumatoid Arthritis Magnetic Resonance Imaging Score at screening. Post completion of the 24-week randomisation period, there will be an option for trial participants to roll over into the open label extension study, where all eligible participants will receive IHL-675A for a further 24 weeks, regardless of the initial treatment arm allocated in the first 24 weeks. The results of this study will establish the safety and efficacy of IHL-675A in rheumatoid arthritis and will be a critical component of future regulatory applications, including contributing to the combination rule assessment in the FDA505(b)2 new drug application dossier.