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Return to introduction on drug discovery ~ LeadDiscovery Reports Efficacy and improved tolerability of Hypericum perforatum extract, WS 5570, compared to paroxetine in patients with moderate to severe depression Depression is the most common mental disorder worldwide affecting around 120 million people globally. The depression market is the largest segment of the CNS market with global sales of US$15.5 billion in 2003 although this figure is dropping as generic equivalents of past blockbusters are launched. Although the depression market has matured, key areas of unmet clinical need will have to be addressed in order to drive further growth of the market. These include improvements in the safety/tolerability of drugs. Extracts from St. John' s wort (Hypericum perforatum) offer competition to synthetic antidepressants and are frequently used particularly in European countries. German phytomedicine company, Dr. Willmar Schwabe Pharmaceuticals has developed an H. perforatum extract, WS 5570, of highly reproducible stability and purity. This extract has already been shown to be significantly superior to placebo in a large clinical trial. Now Schwabe researchers report data from a phase III double blind study showing that WS 5570 is at least as effective as clinical doses of paroxetine in patients with moderate to severe depression. Moreover this efficacy is achieved with few adverse effects. Depression is the most common mental disorder worldwide. It is
estimated that 5.8% of men and 9.5% of women will experience a depressive
episode in any given year. The lifetime risk of developing major depression is
10-25% for women and 5-12% for men. Globally, around 120 million people suffer
from depression and the WHO predicts that depression will become the leading
cause of disability by the year 2020. Depression costs the
Paralleling the high incidence of depression and related costs is a massive market for therapeutic agents. The depression market is the largest segment of the CNS market with global sales of US$15.5 billion in 2003. The dynamics of the marketplace are however changing as patent expiries hit past blockbusters and as new classes of drugs such as the selective noradrenaline reuptake inhibitor, Cymbalta (Eli Lilly), and new formulations of drugs such as the 5-HT1A antagonist, Wellbutrin XL (GSK), are launched. As physicians continue to increasingly prescribe generic
antidepressants the market is expected to decrease by -21.5% to $13.5 billion by
2011. Lilly’s blockbuster antidepressant Prozac (fluoxetine) was particularly
hard hit and its sales fell at unprecedented speed following the loss of
exclusivity in the
Although the depression market has matured, key areas of unmet clinical need will have to be addressed in order to drive further growth of the market (see the depression section of our feature CNS Drug Discoveries: What the future holds). These include improvements in the efficacy, speed of onset, safety/tolerability of drugs and a reduction in remission rates and relapse/recurrence. One class of therapeutic agents that is challenging the
antidepressant class includes various extracts from
Extract of Hypericum perforatum (
In their recent BMJ paper, Szegedi et al report the results of a study sponsored by Schwabe Pharmaceuticals and designed to compare the efficacy and safety of hypericum extract WS 5570 with paroxetine in patients with moderate to severe depression. Results from this 6 week study demonstrated that WS 5570 is at least as effective and better tolerated than standard treatment with paroxetine in the treatment of moderate to severe major depression. The randomised, double-blind, reference-controlled, multicenter phase III clinical trial reports that WS 5570 produced a significantly better improvement in patients as measured using the Hamilton Depression Rating Scale (HAMD) when compared to paroxetine. Although a similar percentage of WS 5570- and paroxetine-treated patients demonstrated a response, WS 5570 induced remission in 50% of patients compared with 35% for paroxetine. Of interest this difference was evident even though patients were allowed to double their treatment dose in the absence of a response after 2 weeks. The adverse event incidence with WS 5570 was 71% lower than with paroxetine. Of particular note paroxetine was associated with diarrhea in 18% of patients compared to only 10% in WS 5570-treated patients. Similar reductions in the incidence of nausea, dry mouth and dizziness were also observed. This study is important for two reasons. Firstly it demonstrates that WS 5570 is at least as effective as SSRIs in the treatment of major depression irrespective of the severity of the depression. Secondly WS 5570 can achieve this efficacy with fewer side-effects than established antidepressants, a key finding given the chronicity of depression.
Entry date
BMJ. 2005 Feb 11; [Epub ahead of print] LeadDiscovery and BioPortfolio aims to provide reliable, insightful analysis on the biotechnology industry. However, this information is provided "as is" and no representations or warranties either express or implied of completeness, accuracy, or of any other nature are made with respect to this information. This information is neither an offer to sell nor a solicitation to buy the securities of any company. This information contains forward-looking statements, which involve risks and uncertainties which may not be listed. The biotechnology industry is an emerging industry and the securities of the companies mentioned in this report have a very high degree of risk and volatility. For this reason, this information is supplied on the condition that the reader will make his or her own determination as to its suitability for any purpose prior to any use of this information. The employees and officers of LeadDiscovery and BioPortfolio may hold positions in some or all of the stocks discussed in this report. This abstract has been produced by LeadDiscovery Ltd. Founded by life scientists for life scientists we aim to help industry identify cutting edge drug discovery options and academic/biotech institutions maximize the potential of their research. Abstracts strictly reflect the opinion of LeadDiscovery's editorial panel. While all reasonable efforts are made to ensure the accuracy of information provided LeadDiscovery and the publisher BioPortfolio, takes no responsibility for incorrect or misleading information. LeadDiscovery is designed for educational and drug development purposes only and is not intended or designed to offer medical advice or advice of any sort, and must not be used for such purpose. The information provided through LeadDiscovery and BioPortfolio should not be used for diagnosing or treating a health problem or a disease and no reliance should be placed on any information contained in this abstract or elsewhere on LeadDiscovery's and BioPortfolio's website. It is not intended to be a substitute for professional care. If you have or suspect you may have a health problem, you should consult your physician or other health care provider. |
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