Incannex has been given the green light to start its Phase 2 clinical trial to assess the safety and efficacy of IHL-675A, a combination drug that combines a specific proprietary formulation of CBD and another long standing prescription drug for rheumatoid arthritis.

Biotech Incannex Healthcare (ASX:IHL)  has received approval from Bellberry Human Research Ethics Committee (HREC) for the lead site Emeritus Research in Melbourne for its Phase 2 clinical trial.

The Phase 2 trial follows the successful Phase 1 clinical trial whereby both active  pharmaceutical  ingredients,  cannabidiol  (CBD)  and  hydroxychloroquine sulphate (HCQ) were absorbed from IHL’s fixed dose combination product IHL-675A.The drug product was also observed to be well tolerated, with no adverse events of concern.

Before starting  clinical  trials, IHL  observed  positive  results  from  an  animal model  of  rheumatoid arthritis.

IHL-675A was observed to be more effective at reducing rheumatoid arthritis across multiple disease assessments including clinical score,  paw  volume,  pannus  score,  total  histology  score  and  serum  cytokine  levels  than  the  rodent equivalent of the standard dose of HCQ or equivalent doses of CBD.

The reduction in disease assessments achieved by IHL-675A was 1.06-3.52 times that observed for HCQ alone at the standard dose.

The promising observations led IHL to prioritise rapid clinical assessment, particularly given that HCQ, marketed as “Plaquenil” and generic equivalents, is a common long-standing treatment prescribed for rheumatoid arthritis with a considerable market profile.


Primary endpoint of Phase 2 trial is pain and function

The  Phase  2  trial will  assess  the  efficacy,  safety  and  tolerability  of  IHL-675A  compared  to  the respective  component  active  pharmaceutical  ingredients  (APIs),  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  study will be managed by Avance Clinical, an Australian and US contract research organisation (CRO).

Recruitment  of additional  sites  with  experience  in  rheumatology  clinical  trials  is  ongoing,  with  the  goal  of  8-10  sites  across Australia and New Zealand being included in the study.

The trial will have 128 participants who meet the eligibility criteria and is designed to include patients who have ongoing pain and reduced function while on stable treatment for rheumatoid arthritis.

Participants will be  randomised  to  one  of  four  arms including either  IHL-675A,  CBD  alone,  HCQ  alone or placebo.  The  primary endpoint for the study is pain and function relative to baseline determined via the score on the RAPID3  assessment.

Participants  will  also  record  their  pain  and  function  outcomes  daily,  by completing questionnaires on pain, fatigue, joint stiffness, and quality of life.

The  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.


Results critical for regulatory applications

The results of the trial will be a critical component of future regulatory applications, including contributing to the combination rule assessment in the US FDA’s new drug application dossier.

“HREC approval for the Phase 2 clinical trial is a key step in the development of IHL-675A for treatment of pain and reduced function associated with rheumatoid arthritis,” IHL chief scientific officer Dr Mark Bleackley said.

“We look forward to working with Emeritus and Avance to assess the effect of IHL-
675A in this patient population.”



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.