Clinical studies are primarily performed on men with advanced prostate cancer (the Royal Shade of Blue). Why? The FDA. FDA only approves new drugs when survival is proven to be prolonged compared to similar men treated with a placebo. The FDA’s insistence on a survival endpoint forces pharmaceutical companies to limit their research to men with a short life expectancy. If survival has to be the endpoint and the study participants live a long time, the cost of performing the study goes up exponentially.
Undergoing experimental therapy with a new medication is reasonable consideration when standard treatment is either no longer working or is causing unacceptable side effects. However, it’s rare for doctors to recommend an experimental medication before other FDA-approved drugs on the market have been tried. The commercially available treatments already proven to extend survival are Lupron, Provenge, Xtandi, Zytiga, Xofigo, Taxotere and Jevtana.
Getting Involved in a Trial Can Be Challenging
Eligibility requirements for participation can be rigorous.
Trials have carefully specified pretreatment and health status criteria: Eligibility
may be denied if the patient is either too sick or not sick enough, if there is
too much previous treatment or not enough previous treatment. Criteria are pre-specified
so that the final results of the trial are not skewed by a lack of uniformity among
patients. Other requirements designed to
achieve trial uniformity include stopping all other anti-cancer medications and
the use of placebos, both of which at times may be at variance with a patient’s
best interest.
An additional challenge is finding the
right trial that matches a patient’s need. The clinical trials landscape changes quickly. New trials are initiated with limited fanfare
and close as soon as they have met their pre-specified number of participants. Trials
available at one center may not be so at another. Another difficulty patient’s face is how to
determine the effectiveness of a prospective study drug. Is it likely to work
or not? Due to a study drug’s newness,
its functional characteristics are often unclear to patients and doctors alike.
There are different types of study designs to consider
each with different goals. Phase I studies, for example, are primarily
designed to learn more about a drug’s side effects. Phase I studies sequentially
escalate medication dosages up to determine the point of dosage intolerability.
Phase II studies treat a group of patients at a fixed dosage to get a
preliminary sense of a drug’s response rates. Phase III studies are the final
step that leads up to FDA approval. Phase
III trials are the placebo-controlled trials.
The Business of Clinical
Trials
Patients contemplating participation in a clinical trial
should be aware that the clinical trial world functions like a business. It’s funded primarily by the pharmaceutical
industry. As such, doctors working in academia are highly motivated to find participants
in their research. If trials are not
completed in a timely fashion funding for new trials will be harder to come by
in the future.
Participating in a clinical trial has become more
attractive over the last ten years as the pharmaceutical industry has made
significant strides toward understanding cancer.
Now that they have access to cancer “blueprints” it’s feasible for
brilliant biochemists to design “software patches,” new drugs that are far more
effective and far less toxic than what has been traditionally available. However, patients need be careful
they don’t mistake a “new” drug for being an “effective” drug. Despite the tremendous advances in research,
most phase I and II drugs still fail to meet minimum standards of clinical
effectiveness and never even advance to phase III testing. Sadly, many of the
potential prostate drugs that have been tested in Phase III studies over the
last ten years have failed to meet the FDA minimum threshold of showing a
survival advantage.
Dr. Scholz is the Principal Investigator at Prostate Oncology Specialists - a list of the active trials are found at http://www.prostateoncology.com/clinical_trials
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