Thursday, 18 August 2011

Searching for Clinical Trials

Looking for a clinical trial can be a daunting experience. It may be that you are doing this just to see what's out there, but it's more likely to be that you - or a friend or family member - have just had some bad news about treatment and you need to review options. At times like this you may not know where to turn. The aim of this article is to offer some guidance in what is likely to be a difficult time.

The first and most important thing to keep in mind is that clinical trials are conducted for different reasons - and this is normally indicated by the phase of the trial. The most important of these are Phase I, II and III trials.

Phase I trials are normally the first trials of candidate drugs or other treatments in humans. To get to Phase I a drug will have gone through 'pre-clinical' testing in the test tube (in vitro) or in animals (in vivo). Occasionally a drug might be tested in tiny amounts in humans before going into a proper Phase I trial. The key aim of the Phase I trial is to find the appropriate dosing of the drug. The effectiveness of a treatment is of secondary importance. The researchers are convinced by the pre-clinical evidence that the drug has some effect, but they need to establish a proper dosing schedule before they can focus on how good it is in practice. This is an important point to keep in mind. Also, Phase I trials tend to be on a small in scale (there are only a few patients, often based at a single hospital or clinic and with small research team).

Phase II trials take things a step further. At this point the drug or treatment has been through Phase I. The dose has been established and there are often some indications of effectiveness. There's still an element of looking at the dosing schedule or treatment protocol, but the emphasis is now on seeing whether the positive effects seen in the pre-clinical studies actually hold true in humans. Phase II studies are often larger in scale - more patients, more doctors, possible multiple locations.

Phase II trials are normally the final stage of testing a treatment before it becomes more widely accepted. It depends on the Phase II trial (or trials, in some cases), showing convincing evidence that a treatment is as good as or better than an existing treatment. It may be that a treatment has the same overall effectiveness as an existing treatment but with fewer side effects or at lower cost or some other benefit. In the best cases a new treatment should be better than an existing treatment and have fewer side effects. Phase III trials tend to be significantly bigger in terms of patient numbers, clinicians involved and the number and range of treatment centres involved.

Now, it should be clear that in terms of desirability, we would be interested in Phase III trials more than Phase II, and Phase II more than Phase I.

Having established what the different phases mean, where do we actually find what trials are going on at the moment?

Each hospital should have one or more doctors who are charged with coordinating the clinical trials at that hospital. This person will know what's available. The chances are that your oncologist will have already discussed your case with this person. If they haven't then you should definitely ask your oncologist to do this.

However, you want to cast your net wider to really get an idea of what may be available elsewhere. So, the first port of call should be the US National Institutes of Health Clinical Trials database (http://clinicaltrials.gov/). Despite this being run by the NIH, the scope is truly international. The user interface is simple to use and you can query on your specific disease, on country of trial, phase of trial and more. You can query on specific drugs as well, if you're interested in following up on something you've found in researching the literature. In addition you can filter on trials that are currently recruiting, as well as on those that have completed. For each trial there's a web page that shows details of the trial and includes contact details, links to related papers or previous results and so on. You can also create RSS feeds so that you are updated with new trials or updates to existing trials. It's a great resource.

Not all clinical trials are on the database, however, particularly some of the smaller Phase I trials. There are other places to look, for example some of the larger drug companies have Clinical Trials Officers who are there to help direct candidates to the appropriate trials. One example is Pfizer, which has a central site dedicated to oncology trials: http://www.pfizercancertrials.com/ but there are others too. They too can help by allowing you to filter by disease, country, phase of trial etc.

What do you do with all of this information? Firstly, it's a good source of contacts. You can email many of the people running the trials and get more details as to whether it's something you seriously want to explore. They are ethically bound not to share results before a study is complete, but they can certainly offer advice. It may be that you strike up a good relationship and can therefore put your oncologist in direct contact with someone running a trial. Even though you may not participate directly in a trial - because it's in a different country, for example - it could be that your oncologist can arrange for you to have access to the drug off-trial. Whether your oncologist is happy that you take on this activity is a separate discussion, but it's your treatment so you have the right to investigate additional options. At the very least you can print off the information about a trial or send them a link so that there's a detailed discussion as to whether a trial or treatment is the right one for your case or not.

There are certainly other sources of information about trials, and I would be more than happy to add them to this article so that other people can refer to them. The important point is that there is a lot of activity out there and all cancer patients should have the knowledge and tools to investigate them.

A separate and more detailed discussion about the ethics of the clinical trial system is something that we will return to in the future.

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