Psilocybin Therapy Success in Phase II GAD Trial

Incannex Healthcare has recently announced preliminary findings from the Phase II Psi-GAD1 clinical trial, which explored the effects of the psychedelic substance psilocybin on individuals with generalized anxiety disorder (GAD). The study indicated that psilocybin therapy led to a notable reduction in anxiety symptoms, with patients showing a marked improvement six weeks post-treatment as measured by the Hamilton Anxiety Rating Scale (HAM-A).
At the commencement of the trial, the average HAM-A score for participants was 29.5, which dropped to 16.8 after psilocybin treatment. This substantial decrease of 12.8 points was considerably higher compared to the 3.6-point drop observed in the placebo group, with statistical significance (p < 0.0001). Nearly half of the patients (44%) experienced a significant reduction in anxiety symptoms, defined by a 50% or more reduction in HAM-A scores. Additionally, a noteworthy 27% achieved complete remission, a figure substantially higher than the placebo group's remission rate.
The treatment's safety profile was also favorable, with psilocybin being generally well-tolerated and causing only mild to moderate side effects. Only one participant chose to discontinue their involvement in the study.
The positive results led to a surge in Incannex’s stock value by 130% prior to the market opening, as reported by Seeking Alpha. The company's CEO, Joel Latham, expressed great enthusiasm for the outcomes, highlighting that this is the first study to investigate psilocybin for the treatment of GAD. He emphasized that the observed improvements in HAM-A scores are more pronounced than those seen with current anxiety medications, suggesting that psilocybin could potentially enhance the lives of millions suffering from GAD.
Incannex is preparing to initiate larger, controlled trials for psilocybin, with the drug candidate designated as PSX-001. The company has also outlined plans for a subsequent Phase IIb trial, named PsiGAD2, which will be conducted at multiple sites in the U.S. and the U.K.
Psilocybin, known for its hallucinogenic properties, acts by stimulating serotonin type 2A receptors, which can alleviate symptoms of depression and anxiety. However, it is a compound that has not been widely studied. Another company, MindMed, has also made strides in the field of psychedelics, reporting in December 2023 that its LSD-derived compound MM-120 showed significant promise in treating GAD, with a 7.6-point reduction in Hamilton scale scores compared to placebo. MindMed's Chief Medical Officer, Dan Karlin, indicated in January 2024 that the company is advancing MM-120 into Phase III trials, with plans to commence these in the latter half of 2024.