Cybin and its partner contract research organisation (CRO) Clinilabs Drug Development have received a Schedule I licence from the US Drug Enforcement Agency (DEA) for the Phase I/IIa clinical trial of CYB003 to treat major depressive disorder (MDD).

A federal prerequisite, a DEA licence is needed for investigators who plan to trial, evaluate, produce, or otherwise work with Schedule I controlled substances.

The first-in-human, double-blind, randomised, placebo-controlled trial will analyse CYB003 in moderate to severe MDD patients.

It is recruiting MDD patients aged between 21 and 55 years who are receiving an antidepressant treatment that is not satisfactory to them.

These subjects will be given two administrations (placebo/active and active/active).

A response/remission will be evaluated following the first and second doses at weeks three and six, respectively.

Trial subjects who are presently receiving antidepressants will be permitted to continue their medication.

In the trial, quick antidepressant effect onset on the dosing day will be analysed using the Montgomery-Asberg Depression Rating Scale. 

The incremental benefit of a second dose of CYB003 given in the third week will also be assessed in the trial, which will offer key PK and safety data to decide on further clinical development. 

The durability of the therapeutic effect for up to 12 weeks will be assessed through an optional period of analysis. 

A deuterated psilocybin analog, CYB003 could possibly address oral psilocybin’s limitations.

CYB003 attained reduced variability in plasma levels, rapid action onset, and briefer duration of effect in preclinical research.

Cybin CEO Doug Drysdale said: “Obtaining a DEA licence for our Phase I/IIa trial is the final step clearing the way to begin dosing participants in our first-in-human study of CYB003. 

“Our rigorous recruitment and enrolment process is well underway and we are excited to commence dosing of our first cohort of participants.”