Thursday, November 30, 2006

Preliminary Results of TORCH trial suggest a greater role for combo therapy in COPD

TORCH stands for "Towards a Revolution in COPD Health" and may well earn the yearly prize for the most self aggrandizing name for a trial . Here is a reference explaining some details of the trial and purported reasons for doing it.

Briefly, this was a 6200 patient trial involving 4 arms one of which was B.I.D.administration of an inhaler with salmeterol 50/fluticazone 500- the others were: placebo, LABA alone and ICS alone. COPD patients had to have a FEV1 less than 60 % to be eligible.

Here is a medical newspaper type writeup of the presentation of the results.

There was an all-cause mortality reduction of 17.5 % which was not statistically significant (p = 0.052). As usual, if one statistical parameter is not what you want, you can always do another which was done. In this case,the other one was the Cox proportional analysis by which the hazard ratio was 0.811 and this was statistically significant at p=0.03 and the COPD death reduction was statistically significant. So does the combo improve survival or not? It seems to depend on what statistical test you think better reflects reality.Within the temple of evidence based medicine, priests may differ as to what statistical incantations best produce the truth.

Life is messy and so often are the results of clinical trials. On balance it does look like the 50/500 combo of a ICS and a LABA seemed to be beneficial but we have not heard the end of the argument over "does it really decrease all-cause mortality". No doubt the statistical brain power that GSK can muster will put forth good argument on the pro side. Already we are hearing terms like "landmark" study" and comments like "new hope for COPD patients". The combo of an ICS and a LABA is already widely used in the treatment of COPD. In COPD, it is standard to use a LABA first and then add on an ICS for more severe disease with the opposite sequence being the rule in asthma treatment.

According to the 2006 GOLD criteria, one should recommend a long acting bronchodilator if the FEV1 is between 50% and > 30 %. This would mean that in the TORCH trial patients were given the combo (ICS + LABA) at an earlier stage than suggested by GOLD.In addition many patients with moderate COPD are given a long acting anticholinergic and later an ICS is added So,in a way the trial differs from usual clinical practice.GOLD 's position is that there is no definitive evidence indicating if a LABA is better or worse than an anticholinergic and with the continuing controversy over the safety of LABAs many doctors may well choose to begin with an anticholenergic particularly since there is now one that is long acting (once a day use), i.e. tiotropium (Spiriva).

My sense of it is that many physicians already would add Advair to Spriva as COPD worsens or for more severely impaired COPD patients and that would be my approach.I doubt the TORCH study will be much a "revolution" though some may add the combo earlier than Stage iii after reading TORCH.

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