Do you think placebo-controlled trials are ethical?

I received a strongly worded email criticising our site for participating in placebo-controlled MS clinical trials; in the opinion of the critic as there are licensed disease-modifying therapies for people with MS, placebo-controlled trials are unethical.

What do you think?

I responded as follows:

“Yes, there are several ethical considerations that need to be taken into account in relation to placebo-controlled MS trials; this issue has been extensively debated and discussed in the literature and there are International guidelines on the conduct of placebo-controlled trials.

In the UK, ethics committees make us insert a statement in the patient information sheet stating that there are licensed therapies and that by participating in a particular study people with MS could be denying themselves active treatment. In addition, we have to reconsent study participants after each relapse and/or confirmed disease progression. In addition, contemporary placebo-controlled trials have rescue arms, which allow study subjects active treatment within a study if their disease becomes active.

It is important to recognise that despite there being licensed therapies some patients don’t want to go onto them because they are injectables; if we did all trials with an active comparator, i.e. an injectable, we would exclude these patients from participating. People with needle phobia and those that have failed injectables because of side effects make up the majority of patients volunteering for placebo-controlled trials. I suspect, however, that once oral therapies are licensed for MS it will become very difficult to recruit subjects for placebo-controlled trials.

The issue of placebo-controlled trials should also be viewed on the background of the limited efficacy of the current injectables and the fact that we still don’t have data on whether or not they impact on the long-term prognosis of the disease.

In summary, I don’t think it is unethical to do placebo-controlled trials. However, you have to do them with carefully designed trials and informed consent. People with MS are perfectly capable of making an informed decision about not taking up the option of going on to a moderately effective first-line therapy and volunteering for a placebo-controlled trial of a new agent. At the end of the day we need to be pragmatic; without clinical trials we won’t advance the field and people living with MS are very aware of this. “


Please have your say if you agree or disagree with this stance!