The final cohort of patients has been dosed in Cybin’s Dosing Phase 2 Trial investigating CYB003 – an investigational deuterated analogue of psilocybin – as a treatment for Major Depressive Disorder (MDD).
The trial is a randomised, double-blind, placebo-controlled study evaluating CYB003 in participants with moderate to severe MDD and in healthy volunteers.
For the study, healthy volunteers receive two administrations of placebo/active and active/active one week apart, and measures of psychedelic effect are assessed after each dose.
Participants with MDD receive two administrations of placebo/active and active/active three weeks apart and response/remission is assessed three weeks after each dose.
Additionally, MDD participants in the trial that are currently being treated with antidepressants will be allowed to remain on their antidepressant medication.
The company has stated that, to date, CYB003 has demonstrated a robust psychedelic response and a favourable safety and tolerability profile at doses of up to 12mg.
The first five cohorts, which dosed 1mg, 3mg, 8mg, 10mg, and 12mg of CYB003, have completed dosing with no serious adverse events and no subject discontinuations due to adverse events. All adverse events reported in the cohorts completed to date were mild to moderate and resolved without the need for any clinical intervention. To date, no unexpected treatment-emergent adverse events have been observed.
Doug Drysdale, Chief Executive Officer of Cybin, stated: “As we begin the final dose escalation cohort in our Phase 2 study, we are moving closer than ever towards our goal of determining an optimal dose for CYB003 and assessing CYB003’s potential as a safe and effective therapeutic for people in need of improved treatment options for major depressive disorder.
“We are very pleased with the excellent safety data for CYB003 in participants to date and look forward to reporting Phase 2 efficacy topline data later this year and preparing for data submission to the FDA for pivotal studies.”
In participants with MDD, the trial is also assessing rapid onset of antidepressant effect on the day of dosing, using the Montgomery-Asberg Depression Rating Scale (MADRS) and evaluate the incremental benefit of a second dose of CYB003 when administered at Week three.
An optional period of assessment will help determine the durability of treatment effect out to 12 weeks.
A topline efficacy data readout from CYB003 Phase 2 clinical trial is expected towards the last two quarters of 2023, and FDA submission of CYB003 Phase 1/2a data for pivotal studies is expected following the readout.
