Lack of commercial pay off is not a legitimate reason for stopping a trial

Education and debate p 603

A large long term randomised trial is a substantial commitment by its sponsor, its principal scientific investigators, a complex international organisational structure, and the patients who agree to participate. For trials with commercial sponsorship, the company's business need—to demonstrate their treatment's advantage—should not conflict with society's need to enhance knowledge by conducting trials with unbiased designs and reporting results without statistical distortion. For both trial sponsors and investigators a tension exists between the “demonstrators” (I want to prove that …) and the “scientists” (I want to find out if …). The goal of regulatory guidelines,1 and indeed the best intention of sponsors, is to ensure that the scientific search for truth of public health relevance is what actually wins through. Another crucial ethical requirement is that no patient should be knowingly harmed by participating in a trial: hence any trial should stop as soon as the primary answer is clear. A paper in this week's BMJ (p 603)2 raises the issue of when else a trial might legitimately be stopped.

Most major trials have an independent data monitoring committee that periodically and confidentially inspects accumulating results for evidence of treatment benefit or harm sufficient to merit …