Incannex said it has received approval from the FDA to conduct its Investigational New Drug (IND) opening Phase 2 clinical trial. The trial will investigate Incannex’s psilocybin pharmaceutical formulation, known as PSX-001, in conjunction with psychotherapy in patients with generalized anxiety disorder in the United States and the United Kingdom.
Incannex submitted the IND application on June 26, 2024 and the FDA completed their review of the application package during the allocated 30-day period. Incannex received communication that the FDA review was completed, and the IND-opening clinical trial, PsiGAD2, is deemed safe to proceed following assessment of the trial protocol, lead trial investigator, and a risk benefit analysis of the trial and prospective drug product.
PsiGAD2 will recruit approximately 94 patients with generalized anxiety disorder, including those currently being treated with selective serotonin reuptake inhibitors, who meet the study inclusion and exclusion criteria. Patients will receive one of two dose strengths of PSX-001 under double blind conditions. There will be two dosing sessions for all patients as well as preparatory and integration sessions to facilitate psychotherapy.
The primary endpoint for the study will be change in HAM-A score, a widely used and validated measure of anxiety, two weeks after completion of the second dosing session. HAM-A scores will be collected at predefined intervals for 23 weeks after completion of the dosing sessions and the change from baseline assessed as secondary study endpoints. Additional endpoints in the study will include measures of quality of life, healthcare utilization, electroencephalography (EEG), as well as assessment of safety and tolerability through adverse event monitoring.
The PsiGAD2 trial builds on the positive results of PsiGAD1, a phase 2 proof of concept clinical trial conducted at world renown Monash University. That trial reported a 12.8 point reduction in HAM-A score in the psilocybin treatment group, which was 9.2 points greater than observed for the placebo group (p<0.0001). In PsiGAD1, 44% of patients in the psilocybin group had a greater than 50% reduction in HAM-A score and 27% of patients achieved disease remission.
PsiGAD2 is also currently under review by the Medicines and Healthcare Products Regulatory Agency (MHRA) in the United Kingdom (UK) to permit the Company to conduct the trial also at sites in the United Kingdom. Incannex will continue start up activities for the PsiGAD2 trial in the UK in parallel with start up in the U.S.
