Thursday, April 2, 2009

Comparator Clinical Trials: What are they and what you need to consider

The point of a clinical trial is the see if a medical treatment (e.g., drug, device, biologic) is 1) safe, and 2) effective for treating the target medical condition. The way this has often been done is to randomly put subjects into 2 groups and give one group the treatment (I'll use the example of a drug for simplicity) and the other group a placebo. The placebo is commonly thought of in the public eye as "a sugar pill". This isn't really accurate, but the idea is close to reality, namely that the placebo is an inert treatment that has no active medical ingredient in it, but looks and feels indistinguishable from the drug. This way, the subjects (and often the doctors) do not know which group is getting the drug and which group is getting the placebo. This helps prevent any bias in the way people respond.

As an aside, note that I use the term "subjects" for clinical trial participants, not "patients". Clinical trial participants are not patients because the treatment being tested is experimental and should not be considered therapy. In fact, the treatment may even be harmful. The whole point of the trial is to determine this issue. Therefore, clinical trial participants, who have graciously and generously agreed voluntarily to put their health at risk for the sake of the trial, are "subjects", not "patients".

Ok, back to the topic at hand.

A recent trend in the clinical trial field is to do a comparator trial, rather than a placebo-controlled trial. This means that the experimental drug is not being compared to a placebo, but rather to a drug that is already being used to treat patients. There are several reasons for this trend.

One reason is because it may be unethical to put clinical trial subjects on a placebo when there is a proven drug already on the market that can help them. For example, if a company is testing a new high blood pressure medication, which is a medical problem that has proven effective drugs that people can use today, it would be unethical to give your control subjects a "sugar pill", rather than a drug that you know is beneficial. This is especially important if the medical indication that is being targeted is life-threatening.

Ethical issues aside, comparator trials are also being heavily promoted by the FDA regulators. Again, the idea is that if a drug is already approved on the market, the FDA wants a company to prove that their drug is just as good, if not better, than the available treatments. This protects patients, because a drug shouldn't be approved to give to patients if it has higher risks and less efficacy than a drug that patients are already taking.

So what does this mean for pharmaceutical companies? Well as you can imagine, a comparator trial is more expensive and considerably more complicated to manage than a placebo-controlled trial. This is because the company not only has to manage the manufacturing and supply of their experimental drug, but they have to manage the procurement and supply of the comparator drug.

If you have experience with this topic, let me know what your thoughts are on this issue.

8 comments:

Pharmaceutical Regulatory Affairs said...

Thanks for this useful post.

Chris said...

Straight-forward definition and explanation - thanks. PHT can confirm this trend from the ePRO side (electronic patient-reported outcomes). Sponsors and CROs are increasing their comparator trials with us.

CTMS EDC Consultant said...

Succinct post! Comparator trails may soon fade placebo based ...

Anonymous said...

At present, podcast is not working but thank you so much for a nice explanation.

Unknown said...

Thanks for explaining it well.

Anonymous said...

Thank you so much you have made me to understand what a comparator is and why it is more effective to use in clinical trials

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Scitech Central said...


Journal of Clinical Trials & Research is an international peer reviewed scholarly journal whose primary aim is to dissemination and development of knowledge on all aspects of clinical trial design, management.Clinical Trials & Research

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