According to the Pharma Times, researchers at the German Institute for Quality and Efficiency in Health Care (IQWiG) report in the British Medical Journal that 74% of the data on patients who took part in trials of Pfizer’s antidepressant Edronax (reboxetine) have not been published until now, and that the published data on the drug overestimate its benefits and underestimate the harms.
Edronax has been approved for the treatment of major depressive disorder in many European countries since 1997, but doubts have been raised about its effectiveness in recent studies and the rejection of its US approval in 2001. Published trials (26% of the data!), however, show a favourable risk-benefit profile for the drug.
IQWiG researchers led by Dr Beate Wieseler sought to assess the benefits and harms of Edronax. They analysed the results of 13 trials, including eight previously-unpublished trials from Pfizer and found data on 74% of patients were unpublished. A further comparison of pubished and unpublished trials showed that the published data had overestimated the benefits of Edronax and underestimated harm.Their review shows that Edronaxas is “a striking example of publication bias” which can affect health policy decisions.
They say that current regulations on the publication of trial results are insufficient and call for drugmakers to be required to publicly disclose data for all drugs - even for those which never get approved. In an accompanying editorial, BMJ editors Dr Fiona Godlee and Dr Elizabeth Loder warn that “the medical evidence base is distorted by missing clinical trial data” and call for “urgent action is needed to restore trust in existing evidence.”
Effectively the clinical literature is being distorted by omission and we're being misled. IQWiG has described publication bias as one of the most important and dangerous sources of error in medicine. Not coincidentally, this echoes claims raised by Professor Donald Light that pharmaceuticals is a "market for lemons"
Three reasons cited by Prof. Light for the pharm industry's "lemon production" are:
- Developer companies in charge of testing their own drugs
- Legal protections that allow information about harms and effectiveness to be hidden
- Low bar for drug efficacy that must be met for a new drug to be approved
Selective publication of results to suit a company's interests in getting a drug approved goes to point two (bold face) above and speaks to IQWiG's/editors of BMJ concerns as well.
Posted by Bruce Lehr October 14th 2010.
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