Blind and Double Blind—Sound Ominous?

Those terms certainly sound dangerous. But in the world of cancer clinical trials they refer to methods used to make sure experimental drugs are fairly and accurately tested. Blinded studies are also called randomized studies, although not every randomized study is blinded. Just to clear the air about eye safety, the term “blinded” originated when early participants were actually blindfolded—not likely to happen today.

In many clinical trials two or more drugs are compared in the experimental process. In order to make sure all participants are treated equally, they may not be told which of two or more treatments they are receiving—experimental drug (new), standard drug (the best now available), or maybe even a placebo (see previous entries about placebos) if no standard drug exists. This is a “blind” or “blinded” study. If you participate in a blinded study you will not know and will not be able to choose which treatment you receive. This is common in clinical trials.

It is also common for a blinded study to be a “double blinded” study. This is a second step to insure that all participants and all medical procedures are as fair and equal as possible. In a double blind study not only doesn’t the trial participant know what treatment they are receiving, but the doctors, nurses, and other personnel directly administering the trial do not know either. It is possible to be unblinded and know what one is getting - although this is rare. In general, unblinding happens only if there is a severe side effect and the care of the patient requires knowing what drug he or she is receiving.  Unblinding also happens when the clinical trial is over.

While this may seem frustrating for those involved, blinding increases the chances of determining the actual benefit (if there is one) of the experimental treatment being tested in the trial. 

Ominous? Of course not. It’s all just another part of the clinical trial process.

To put a smile on your face see Larry's latest cartoon


(c) 2012 Tom Beer and Larry Axmaker

Does joining one cancer clinical trial disqualify you from joining another trial?

Participating in one clinical trial does not necessarily disqualify you from future trials, as long as you meet the future study criteria. Many people participate in more than one clinical trial over time. Rules for trial participation do take into consideration therapy that you have received prior to joining a trial, and a prior treatment that you have received—either standard or experimental—might make you ineligible. If you already know you might be interested in a specific trial sometime in the future, check with your doctor or clinical trial site to see if the treatment decisions you make today could get in the way later. For the most part, however, many other clinical trials are available, and even if one particular study is off limits to you, another is likely to become available.

Waiting for the new drug to be approved…

Not all clinical trials end with a successful drug or treatment being approved by the FDA. But when the trial is successful we want the new drug to be available today—if not sooner. It seems like it takes forever for the FDA to review and finally approve a drug, especially if it’s one that might benefit us.

In a study recently published by the New England Journal of Medicine, two researchers from the Yale School of Medicine studied the average time from clinical trial to approval by the FDA in the U.S., the European Medical Agency (EMA), and Health Canada between 2001 and 2010.

Although the average approval time still may seem long, the FDA approval time was more than two months faster than the EMA and more than three months faster than Health Canada.

Average drug approval times:

FDA                            322 days

EMA                           366 days

Health Canada         393 days

Approval agencies around the world are always under pressure to approve potentially successful drugs as soon as possible and many approvals are done in less time than the averages shown here. It is worth noting also that a long approval time may mean that the study results are not as clear cut as it seems and the FDA needs to ask more questions. The other side of the coin, of course, is when a drug may be approved too quickly and then have to be recalled because of risks and problems not known at the time of approval.

To put a smile on your face see Larry's latest cartoon.
To learn more about clinical trials, take a look at our book.
(c) 2012 Tom Beer and Larry Axmaker

Podcast: Drs. Armstrong and Beer discuss new prostate cancer treatments

Podcast of Dr. Andrew Armstrong and Dr. Tom Beer speaking about new treatments for the most advanced form of prostate cancer.  Listen by clicking on the MP3 icon to the left.  You can also read the text of the interview and listen to the podcast at the Cancer Network website.

To put a smile on your face see Larry's latest cartoon


(c) 2012 Tom Beer and Larry Axmaker

Clinical trial phases from the participant's point of view

There are many types of clinical trials.  Most commonly, they are divided into phase I, II, III, and sometimes IV.  The phases refer to the phases of testing of a new drug in humans. Some our previous posts describe the various phases and discuss phase I trials and phase III trials in more detail.  Here we would like to share with you page 47 from our book, where we provide a succinct summary of the advantages and disadvantages of each trial type, from the perspective of trial participants.  The table shown below may not apply to every single trial, but it does give you a quick and straight forward basic guide.

If you would like to download a PDF of this page you can do so here.  Feel free to share it.

To put a smile on your face see Larry's latest cartoon.

To learn more about clinical trials, take a look at our book.
(c) 2012 Tom Beer and Larry Axmaker