Global Insight Perspective | |
Significance | U.S.-based Lilly has touted the results of a study that suggests its antidepressant Cymbalta has a significant clinical benefit for the sexual function of male patients over major rival Lexapro. |
Implications | According to Lilly, an estimated 70% of patients who suffer loss of sexual functioning due to medication discontinue treatment, which can have a major detrimental impact on their illness. |
Outlook | The results of this study could give Cymbalta a significant edge over Lexapro, allowing it to gain market share from this leading member of the SSRI class of antidepressants. |
According to U.S.-based Eli Lilly & Co, a new head-to-head study of male patients with major depressive disorder (MDD) has found that those using Cymbalta had significantly better sexual functioning than those treated with rival antidepressant Lexapro. The study of 680 patients found that 37% of male patients treated with Cymbalta reported a worsening of sexual function, as measured by the Changes in Sexual Functioning Questionnaire (CSFQ). This compared favourably to the 59% of MDD patients treated with Lexapro, and the 49% taking a sugar pill. However the difference between the two drugs in affecting the sexual functioning of women was minimal, with 36% of female patients treated with Cymbalta reporting a worsening of sexual functioning compared to 38% of patients taking Lexapro. Dr Madeline Wohlreich, a co-author on the study and medical advisor for Lilly, suggested that this small difference among female patients could be because ‘sexuality in women is more affected by relationship and mood issues’, reports The Indianapolis Star.
At the end of the acute period of sexual functioning assessment, Lilly highlighted the following key findings:
- At four and eight weeks there was no statistical difference in sexual functioning between patients taking Cymbalta and a sugar pill. Conversely, those taking Lexapro did report a statistically significant worsening.
- At eight weeks sexual functioning in male patients taking Cymbalta was significantly better on the CSFQ compared to Lexapro. However, there was no statistical difference among female patients.
- The study suggested that anorgasmia was the only treatment-emergent sexually adverse event that occurred statistically more frequently for Cymbalta or Lexapro over a sugar pill.
- At the end of the study, there was no statistical difference in discontinuation rate due to sexual side effects.
The sexual functioning assessment formed part of a larger Lilly-sponsored study comparing the efficacy of the two drugs, in which the primary endpoint was to compare the onset of efficacy between Cymbalta and Lexapro. In terms of the speed of efficacy Cymbalta, a leading member of the serotonin and norepinephrine reuptake inhibitor (SNRI) class of antidepressants, failed to show an advantage over its selective serotonin reuptake inhibitor (SSRI) rival Lexapro, although the study did show that the onset of activity of Cymbalta was at least as fast as Lexapro. While Lilly will not be able to find any major upside from this finding, the data from the sexual functioning improvements could prove a strong positive for its drug.
Outlook and Implications
Sexual dysfunction is a common symptom among patients suffering with depression and, according to Lilly, affects up to 64% of patients with the illness. However, additional antidepressant medications can also have an impact on sexual functioning. Although there was no statistical difference in discontinuation rates in this study between Cymbalta and Lexapro due to sexual side effects, co-author Dr Madeline Wohlreich still asserted that ‘when sexual dysfunction due to medication occurs, a person may be inclined to stop treatment’. This discontinuation of treatment – which occurs among an estimated 70% of patients who suffer a loss of sexual functioning due to medication - can have a devastating impact on the patient.
This study could prove a considerable positive for Cymbalta as it attempts to gain market share, not only from Lexapro but from the SSRI class of anti-depressants as a whole. These findings could prove a strong motivation for physicians to switch patients over to Cymbalta, and could also allow the drug to make further ground on its main rival among the SNRI class of anti-depressants, Effexor (venlafaxine), from U.S.-based Wyeth.
Cymbalta has made rapid inroads into the market share of its competitors since its 2004 launch. In 2005, the drug led all branded and promoted products in share of market growth in the antidepressant market, in a year that was generally considered a tough one for antidepressant medications. This strength in Cymbalta sales was carried through into the first quarter of 2006, where it generated US$233.3 million in sales, a 118% jump from the year before. Lexapro, from New York-based Forest, was approved for marketing in the U.S. in 2002. It garnered US$464 million in first quarter of this year.
Related Articles:
- United States: 21 April 2006:New Products Drive 13% Increase in Eli Lilly's Q1 Earnings
- United States: 14 December 2005: Eli Lilly Touts Positive Results from New Cymbalta Study
- United States: 12 December 2005: Eli Lilly Announces Bullish Outlook and Seeks to Extend Cymbalta's Indications