This open-label, Phase III long-term extension trial (n=468 estimated) assesses the safety and long-term efficacy of CYB003 in participants with MDD; participants may receive up to three 16 mg CYB003 medicine sessions ~3 weeks apart while continuing stable antidepressant therapy.
EXTEND is a single-group long-term extension of the double-blind APPROACH and EMBRACE trials to evaluate safety and sustained efficacy of CYB003 (a deuterated psilocin analogue) in participants with major depressive disorder who previously participated in the parent studies.
Participants continue their stable antidepressant medication and receive psychological support; dosing consists of two medicine sessions ~3 weeks apart, with an optional third 16 mg dose if relapse occurs. Safety monitoring includes ECG and assessments for arrhythmia, suicidality evaluation (C-SSRS) and urine/breath drug/alcohol testing.
Planned enrolment is estimated at 468 across US sites; sponsor is Cybin IRL Limited.
Single-group extension: eligible participants receive 16 mg CYB003 in two medicine sessions ~3 weeks apart; a single additional 16 mg dose permitted if relapse (max 3 doses). Participants continue stable antidepressant medication and receive psychological support.
Deuterated psilocin analog; initial 2 doses given ~3 weeks apart; optional third dose if relapse.