New data suggest that Cymbalta (duloxetine HCl) 60 mg to 120 mg once daily delayed the onset of a new episode of depression in patients who had previously responded to the medication and who had recurrent depressive disorder, defined in the study as those patients who experienced at least three depressive episodes in the previous five years, compared with placebo (p < .001).
Results from the 52- week maintenance phase of the longest controlled duloxetine study completed to date were presented at a meeting of a major scientific society today.
Additionally, patients who were treated with duloxetine were less likely (p < .001) to experience a new episode of depression than those who received placebo (recurrence rates were 14.4 percent vs. 33.1 percent, respectively).
Previous research has shown that up to 85 percent of patients with depression will experience depressive recurrences.(i) The number of episodes,(ii) their duration(iii) and the presence of lingering depressive symptoms increase the risk of recurrence, or future episodes of depression.(iv)
In the placebo-controlled maintenance phase of the study that followed initial open-label acute and continuation treatment phases, the most common adverse events (those occurring in at least 5 percent of patients in any treatment group) were headache, insomnia, dizziness, fatigue, back pain, common cold and flu.
Additional Study Findings
- Time to worsening of depressive symptoms was significantly longer (p = .006) in the duloxetine-treated group compared with the placebo- treated group. This was defined as a 50 percent increase from baseline on the 17-item Hamilton Rating Scale for Depression (HAMD17) total score and a Clinical Global Impressions of Severity (CGI-S) score of 3 or more at anytime during the maintenance phase.
- Patients taking duloxetine experienced less worsening in symptom severity during the 52-week maintenance phase as measured by efficacy measures including the HAMD17 total score and subscales, the CGI-S and the Patient's Global Impression of Improvement (PGI-I) scales, compared with those taking placebo (p-values < .01).
- Patients taking duloxetine experienced a similar worsening in somatic symptom severity during the 52-week maintenance phase as measured by Visual Analog Scales (VAS) for pain and the Symptom Questionnaire- Somatic Subscale (SQ-SS), compared with those taking placebo (p-values > .05).
- The proportion of duloxetine-treated patients who discontinued the study due to adverse events during the acute, continuation and maintenance phases was 6.6 percent, 6.1 percent and 4.1 percent, respectively. The following were the most common treatment-emergent adverse events:
- Acute phase:
- nausea,
- headache,
- dry mouth
- excessive sweating
- In addition, there was one person who did not complete the acute phase due to a completed suicide, which was determined by study investigators not to be attributed to treatment.
- Continuation phase:
- headache,
- common cold
- excessive sweating
- Maintenance phase:
- headache,
- back pain
- common cold
The 52-week maintenance phase was preceded by up to 34-weeks of open-label treatment with duloxetine 60-120 mg once daily. Of the 514 patients initially entered into the study, 288 patients met response criteria at the end of up to 34 weeks treatment and were entered into the 52-week, double-blind, maintenance phase of the study. During the maintenance phase, patients were randomly assigned to receive either duloxetine at the dose to which they had previously responded, or placebo.
The primary endpoint of the study was time to recurrence of a major depressive episode during 52 weeks of maintenance treatment, as assessed by any of the following recurrence criteria: a CGI-S score greater than or equal to 4 and meeting DSM-IV criteria for major depressive disorder; three consecutive visits meeting re-emergence criteria or 10 total re-emergence visits; or study discontinuation due to lack of efficacy. Secondary measures included the HAMD17 total score and subscales, CGI-S and PGI-I scales, SQ-SS and VAS for pain. Safety and tolerability were assessed via analysis of treatment-emergent adverse events, vital signs, weight, ASEX for sexual functioning and laboratory measures. The primary study manuscript has already been submitted for review with a view to publication in a peer-reviewed medical journal.