Phase II results for Cybin’s psilocin therapy showed remission rates of 71%, but just eight patients made it to the 12-month milestone.
Cybin has reported 71% remission in patients with major depressive disorder (MDD) who received two doses of the psilocin therapy CYB003 during a Phase II clinical trial.
The therapy also reduced severity of the disorder as measured by the Montgomery-Asberg Depression Rating Scale (MADRS), with a 23-point reduction compared to baseline at 12 months.
Shares of Toronto-based Cybin rose 14% on the news as the markets opened Monday to $13.25 apiece.
CYB003 is a psilocin, a class of molecules that are structurally similar to neurotransmitters such as serotonin. The therapy has been granted a breakthrough tag from the FDA as an adjunctive treatment for MDD. The company touted the results as validation of the dosing regimen and confirmation of CYB003’s highly durable effect and potential for sustained relief.
But the patient pool was very small, with just eight participants reaching the 12-month follow-up in the 16-mg cohort and just seven of those receiving the two doses. All of those patients responded to the therapy and 71% achieved remission. The two patients who received two doses but did not achieve remission fell just short of the MADRS score to be considered in remission, Cybin said.
For the 12-mg cohort, Cybin reported an 18-point reduction in MADRS score, with 60% of patients responding and half reaching remission. There were no adverse events.
Cybin launched a Phase III program for CYB003 last week as an adjunctive treatment for MDD. Topline results from the program are expected in 2026.
Neuropsychiatry is a historically difficult disease area, with many companies failing to convert early-stage success into a Phase III win. Sage Therapeutics recently dropped an MDD indication for Zurzuvae, which was approved by the FDA for postpartum depression but not the more common condition in August 2023.
In October, Alto Neuroscience’s MDD drug ALTO-100 failed in a Phase IIb study, just nine months after the company went public. In response, William Blair noted that “historically placebo-controlled MDD studies have been high-risk.” Alto has another MDD readout expected in 2025 for ALTO-300, which is already approved for depression in Europe and Australia.
Cybin also faces a tumultuous psychedelics space, following the FDA’s August 2024 rejection of Lykos’ MDMA-based PTSD therapy. But Cybin CEO Doug Drysdale told BioSpace at the time that the guidance the agency provided with its rejection could actually benefit psychedelics developers.
“It’s actually in some ways helpful to have all this feedback from the adcomm and from the FDA because we can incorporate that into our programs ahead of time.”
