GSK: new Seroxat claims 'pointless'

A fresh look at data used by GlaxoSmithKline (GSK) in 1989 to secure marketing authorisation for antidepressant Seroxat (paroxetine) in the UK has pumped the bellows in the fiery debate over whether both adults and children taking the drug are at a significantly increased risk of exhibiting suicidal tendencies.

In defence of its tarnished selective serotonin reuptake inhibitor (SSRI), Seroxat, GlaxoSmithKline was moved to unleash a frank and candid criticism of a scientific paper written by researchers at Norway's University of Oslo and published in the BMC Medicine journal.

The new paper, which reviewed some 16 randomised and, for the large part, previously unpublished studies of the drug, concluded that `the data strongly suggest that the use of SSRIs is connected with an increased intensity of suicide attempts per year' and that `the recommendation of restrictions on the use of paroxetine for children and adolescents conveyed by regulatory agencies should be extended to include usage by adults'.

The data show that in 1,466 people, there were seven suicide attempts among the 916 people randomized to receive Seroxat, but just one among 550 placebo recipients.

The Seroxat-suicide link has already been levelled at GSK, though largely in relation to its use in children and adolescents and/or during the process of treatment withdrawal. The Norwegian revelations portray the data in such a way as to account for the risk to adults as well as to take the exposure time of the patients `properly into account' by comparing intensities (rather than numbers) of suicide attempts per year in drug and placebo groups.

Defence

The response by GSK, which likely hoped that the matter had been laid to rest following a difficult period of in-depth debate last year, was to try and snuff out a repeat insurgence by branding the Norwegian findings ìmisleadingî and serving ìonly to cause confusion and unnecessary concern for patients using an SSRI such as paroxetine for treatment of depressionî.

In vehement disagreement with the Oslo researchers' conclusion, GSK hit out at the work claiming that it ìfocuses on incorrectly selected data collected 15 years agoÖ [and] fails to acknowledge the current body of dataî.

The latest pool of data is, the firm pointed out, ìsignificantly more extensive and has been recently reviewed by EU authorities,î adding that earlier this year the European Medicine Agency's (EMEA) Committee for Medicinal Products for Human Use (CHMP) reaffirmed Seroxat's positive risk-benefit scenario for adults with depression following a re-examination of all existing safety and efficacy data, both published and unpublished.

Yet, as the data used in the Norwegian study was the same as that submitted to the UK's Medicines and Healthcare products Regulatory Agency (MHRA), which subsequently issued marketing approval to GSK, there is also a finger pointing at the regulator.

The MHRA this week admitted that it `cannot rule out a modest increase in the risk of suicidal thoughts and self-harm for SSRIs compared with placebo', yet a statement made no attempt to clarify its position over the risk specifically to adults or whether any related prescribing limits should be issued.

It added that the safety of the entire SSRI class is under continual review.