How many patients typically participate in each phase of the clinical trial?

Clinical trials are often described as phase I, II, III, and sometimes phase IV.  The number of participants varies greatly depending on the phase of investigation, but also depending on the cancer type, situation, and expected outcome.  Phase I trials are principally charged with determining the safe and optimal dose of a new drug or drug combination.  Such trials may involve 20 to 40 patients.  Phase II trials are where the potential of a drug to be effective is first evaluated.  Typical phase II studies range in size from 50 to 250 participants.  The higher end of that range is more common in randomized phase II studies where 2 or more doses or drug combinations are being examined side by side.  Phase III trials are the ultimate test of a new treatment.  Participants are randomly assigned to the new treatment or the current standard.  These trials involve hundreds and sometimes thousands of participants.  The number of participants needed is determined by the question being asked, the expected magnitude of the difference between the two treatments, and the percentage of patients who are expected to experience the outcome being measured.  For example, trials that seek to reduce the risk of cancer recurrence are often very large in part because many of the participants (thankfully) don’t suffer a recurrence at all.  A large number of participants are therefore needed to make sure that enough of them have a recurrence so that a difference can be detected.

For more questions and answers about clinical trials, visit the Talk about Health website.
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

How does the FDA know about new side effects for a drug that has already been approved?

The FDA has surveillance programs in place to monitor the safety of drugs after approval.  These programs primarily rely on physicians reporting to the FDA the side effects they see.  While not all physicians routinely make such reports, enough do that unexpected side effects usually come to light.  For some drugs that are approved with some questions about safety, special requirements can be put into place.  These might include so called phase IV studies to gather more safety data or special prescribing programs for high-risk drugs.

For more questions and answers about clinical trials, visit the Talk about Health website.
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

Hormonal Therapy for Prostate Cancer - Education Video

In an occasional departure from our focus on clinical trials, we thought we would share our latest patient education videos for prostate cancer patients.  Here Dr. Beer discusses hormonal therapy for prostate cancer - very much the way it would be discussed in a clinic visit. 


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

In the US, who decides what cancer research is funded and how much funding each project receives?

There is no single authority that allocates cancer research funding.  Each funder has a process.  The largest source of funding for research is the National Institutes of Health which uses a peer-review process.  Panels of researchers review and rank research proposals.  This is probably the best process we have.  It is independent and invites the best thinkers to drive it.  Sometimes this process does, however, end up emphasizing funding for ideas that fit well with today’s thinking.  Unconventional ideas may not always be appreciated by peer scientists.  The pharmaceutical industry is the other large source of funding.  It allocates funding largely based on it’s view of market opportunities for new drugs, although industry also provides funding for independent research.  Many private foundations, and government agencies other than the National Cancer Institute are also important.  They generally follow the peer-review process or some variation on it.

For more questions and answers about clinical trials, visit the Talk about Health website.
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