The results of the 12-week open-label, single-group study are positive, study investigator Michael Cronquist Christensen, MPA, DrPH, a director with the Lundbeck pharmaceutical company, told this news organization before presenting the results in a poster at the 15th Clinical Trials on Alzheimer’s Disease conference.
“The study confirms earlier findings of improvement in both depressive symptoms and cognitive performance with vortioxetine in patients with depression and dementia and adds to this research that these clinical effects also extend to improvement in health-related quality of life and patients’ daily functioning,” Dr. Christensen said.
“It also demonstrates that patients with depression and comorbid dementia can be safely treated with 20 mg vortioxetine – starting dose of 5 mg for the first week and up-titration to 10 mg at day 8,” he added.
However, he reported that Lundbeck doesn’t plan to seek approval from the U.S. Food and Drug Administration for a new indication. Vortioxetine received FDA approval in 2013 to treat MDD, but 3 years later the agency rejected an expansion of its indication to include cognitive dysfunction.
“Vortioxetine is approved for MDD, but the product can be used in patients with MDD who have other diseases, including other mental illnesses,” Dr. Christensen said.
Potential neurotransmission modulator
Vortioxetine is a selective serotonin reuptake inhibitor and serotonin receptor modulator. According to Dr. Christensen, evidence suggests the drug’s receptor targets “have the potential to modulate neurotransmitter systems that are essential for regulation of cognitive function.”
The researchers recruited 83 individuals aged 55-85 with recurrent MDD that had started before the age of 55. All had MDD episodes within the previous 6 months and comorbid dementia for at least 6 months.
Of the participants, 65.9% were female. In addition, 42.7% had Alzheimer’s disease, 26.8% had mixed-type dementia, and the rest had other types of dementia.
The daily oral dose of vortioxetine started at 5 mg for up to week 1 and then was increased to 10 mg. It was then increased to 20 mg or decreased to 5 mg “based on investigator judgment and patient response.” The average daily dose was 12.3 mg.
In regard to the primary outcome, at week 12 (n = 70), scores on the Montgomery-Åsberg Depression Rating Scale (MADRS) fell by a mean of –12.4 (.78, P < .0001), which researchers deemed to be a significant reduction in severe symptoms.
“A significant and clinically meaningful effect was observed from week 1,” the researchers reported.
“As a basis for comparison, we typically see an improvement around 13-14 points during 8 weeks of antidepressant treatment in adults with MDD who do not have dementia,” Dr. Christensen added.
More than a third of patients (35.7%) saw a reduction in MADRS score by more than 50% at week 12, and 17.2% were considered to have reached MDD depression remission, defined as a MADRS score at or under 10.
For secondary outcomes, the total Digit Symbol Substitution test score grew by 0.65 (standardized effect size) by week 12, showing significant improvement (P < .0001). In addition, participants improved on some other cognitive measures, and Dr. Christensen noted that “significant improvement was also observed in the patients’ health-related quality of life and daily functioning.”
A third of patients had drug-related treatment-emergent adverse events.
Vortioxetine is one of the most expensive antidepressants: It has a list price of $444 a month, and no generic version is currently available.