Regulatory Decision Summary for Viibryd

Vilazodone (the medicinal ingredient of Viibryd) is a new chemical entity with affinity for the serotonin (5-HT) reuptake site as well as the serotonin-1A (5-HT1A) receptor. Non-clinical studies showed that it potently inhibits the reuptake of serotonin, and acts as a partial agonist of the 5-HT1A receptor.

The sponsor submitted four randomized, double blind, placebo-controlled pivotal studies to support the indication. In each study, the primary endpoint was the mean difference in Montgomery-Åsberg Depression Rating Scale (MADRS) score from baseline to 8 or 10 weeks (depending on the study). This primary endpoint is validated and commonly used to support an indication for the treatment of symptoms associated with MDD.

Patients participating in these studies were selected according to acceptable inclusion criteria similar to other MDD studies. There was a slight preponderance of women, which aligns with the demographics of people diagnosed with MDD. The efficacy in women and men were similar. There were not enough patients of races other than Caucasian to assess any possible differences in efficacy or safety.

The safety profile of Viibryd is similar to other selective serotonin reuptake inhibitor (SSRI) antidepressants with only diarrhea being reported to an uncommon degree. Additional information has been included in the adverse reactions and Patient Information sections of the Product Monograph (PM) to inform practitioners and patients of the characteristic safety profile of Viibryd.

While there were no electrocardiogram (ECG) or blood pressure safety signals noted in Phase III studies, statistically significant effects on blood pressure were seen at therapeutic doses in a QT study. However, these effects were relatively small and may have been due in part to decreases seen in the placebo treatment. Regardless, a cautionary class statement was included in the Warnings and Precautions section of the PM with clarification of the data in the Adverse Reactions section. The PM has also been updated with class wording for all antidepressants on behavioural and emotional changes, including self-harm.

Depression is a common disorder and can be quite debilitating. While there are currently many effective approved antidepressants, response to treatment varies between patients and many benefit from switching from one treatment to another. Similarly, despite comparable safety profiles, patients may find that they tolerate some antidepressants over others. Consequently, given the similar safety and efficacy profiles of Viibryd to other SSRIs, an additional treatment option for patients would be beneficial. 

Risk-Management Plan (RMP):

Assessment of the Viibryd RMP did not result in the identification of any major deficiencies. Minor deficiencies were identified and updates to the RMP should be reviewed by Health Canada. All recommendations to labelling have been addressed in the PM.

For more information on Health Canadas decision, please view the Summary Basis of Decision.