Feb 8, 2012

Phase I cancer trials: the newest drugs, but not for everyone

Access to the latest and newest drugs sounds very compelling, but it isn't always the best choice for all cancer patients.  The latest drugs are first tested in phase I studies and these studies are not for everyone.  Phase I studies (clinical trials) may be appropriate when the cancer is not responsive to standard treatments or no standard treatments exists. Since we don’t know much about how successful the new drugs in phase I studies will turn out to be, proven treatments should be tried first.
Classic phase I studies are designed almost exclusively to test the safety of various doses of a brand new drug. The drug has already been analyzed and evaluated in laboratory animals, and has shown promise for the treatment of cancer in the laboratory.  Effectiveness may also be evaluated, but this is secondary to the primary goal of documenting side effects and safety and sorting out what the optimal dose of the drug will be in human beings.
There are examples of drugs that yielded spectacular results even in their first phase I trial, but for most participants that is not their experience.  
Drugs in phase I studies are often given in low doses (to keep things safe) and help little or not at all.  Across all phase I studies, around 5% of cancer patients experience a clinically important tumor response.  This does not mean that most drugs are ultimately proven worthless.  The low response rate may be related to low doses of drugs that many patients receive and also to the fact that many patients only participate in phase I trials after they tried many others therapies.  Their cancers are often quite resistant to any treatment. 
If no other treatments have worked, a phase I trial may be a good option, but be sure to double check that reliable standard options or even phase II or III studies that are testing drugs already shown to be safe are not a good idea first.

(c) 2012 Tom Beer and Larry Axmaker