Canadian pharmaceutical company Xenon Pharmaceuticals has reported topline data from the Phase II X-NOVA clinical trial of XEN1101 to treat patients with moderate to severe major depressive disorder (MDD).

The randomised, placebo-controlled trial is designed to assess the safety, tolerability and clinical efficacy of 10mg and 20mg doses of XEN1101 in 168 patients.

Its primary endpoint was the variation in the Montgomery-Åsberg Depression Rating Scale (MADRS) after six weeks.

According to the findings, mean declines of 15.61 and 16.94 in the XEN1101 10mg and 20mg arms were observed respectively, compared with 13.90 in the placebo arm.

Though the dose response following XEN1101 treatment was clear and 'clinically meaningful', it was not statistically significant against that of placebo.

The XEN1101 treatment achieved statistical significance on the Hamilton Depression Rating Scale, as well as change in the Snaith-Hamilton Pleasure Scale, which measured anhedonia. 

In addition, XEN1101 was found to be well-tolerated with comparable adverse event rates across all treatment groups.

No XEN1101-associated serious adverse events (SAEs) were observed in trial, but 3.6% of the subjects in the placebo arm experienced a treatment-emergent SAE.

Xenon Pharmaceuticals president and CEO Ian Mortimer said: “Based on the totality of data from this study, including clinically meaningful drug activity in depression and anhedonia, we are actively exploring the future development of XEN1101 in MDD and potentially other indications as we believe this mechanism has potential broad applicability.

“We believe that the data from this study in depression further build upon XEN1101’s compelling product profile in our ongoing Phase III development in epilepsy. 

“We believe the new clinical data we have generated through X-NOVA further support the potential of XEN1101 to have a highly differentiated profile in the treatment of epilepsy given the significant co-morbidity of depression in epilepsy patients.”