After failing to impress investors a year ago with an initial look at phase 2 data of a psilocybin-derived compound in major depressive disorder (MDD), Cybin momentarily boosted their spirits with a longer-term analysis. Twelve months after two 16 mg doses of the drug, called CYB003, seven patients saw their scores on the Montgomery–Åsberg Depression Rating Scale, a measure of depression symptom severity, improve by an average of 23 points from baseline.
Cybin announced the results in a Nov. 18 release. Investors responded by initially boosting the biotech’s stock price by as much as $1.49 per share as of 9:50 a.m. EST, an increase of 12.8% from Friday’s close. After 10:30 a.m., the stock price cooled back down to previous levels.
The full 12-month trial had no placebo group, though some patients received individual doses of placebo as part of their CYB003 treatment regimens. Cybin initiated placebo-controlled phase 3 trials on Nov. 13.
“We previously reported response and remission rates of 75% at four months. By the 12-month mark, response rates improved to 100% while 71% of participants were still in remission,” Cybin chief medical officer Amir Inamdar said in the release.
The two patients who responded to treatment but weren’t in remission at 12 months had MADRS scores of 11, Cybin noted in the release; remission requires a score of 10 or less.
Investigators recorded no new adverse events in the 12-month follow-up, Cybin said, including no reports of suicidality. In the previous data drop, the company reported no treatment-related adverse events six weeks after 12 mg or 16 mg doses.
In February 2023, prior to announcing the interim phase 2 data, Cybin cut its workforce by 15% in an effort to save cash.
Other biotechs have struggled recently to get antidepressants across the finish line. Sage and Biogen’s zuranolone was rejected by the FDA last year for MDD and only approved for the smaller indication of postpartum depression.
And in 2019, an NMDA receptor modulator that Allergan acquired when it bought Naurex for $560 million flopped in a phase 3 MDD trial.
Editor's note: This story has been updated to reflect the use of placebo in the phase 2 trial.