FDA Will Review Two Medications for Prostate Cancer Prevention

GlaxoSmithKline, manufacturer of Avodart, and Merck, manufacturer of Proscar, have requested that the U.S. Food and Drug Administration add new official information for their respective medications. Both companies are advocating the use of these two medications as risk-reducers for prostate cancer, reports CBS News.

The two pharmaceutical industry giants have provided the governmental agency with results of studies performed on each drug that they feel represent important findings to reduce male risk of developing prostate tumors. If the FDA grants one or both requests, the medications would be a historical first in the prevention of this disease.

While the CBS News article title states that these are new drugs, the medications are already on the market for other uses. GlaxoSmithKline is asking the FDA to add the reduced risk of prostate cancer to the list of approved indications for prescribing the medications. Physicians do sometimes prescribe medications for what's termed "off-label use," but there is a decreased likelihood for malpractice risk if physicians follow a medication's label indications.

Merck is asking the FDA to allow the company to include the information from their Prostate Cancer Prevention Trial (PCPT) in the clinical studies and adverse events sections of Proscar's label, according to the FDA's Dec. 1, 2010, ODAC Briefing Document.

Avodart and Proscar

Avodart, or dutasteride, and Proscar, or finasteride, were developed for the treatment of benign prostatic hyperplasia (BPH), explains Gold Standard. BPH causes the prostate gland to enlarge, causing a variety of symptoms including urinary retention and difficulty urinating. Both of these prescription agents act to reduce those symptoms and reduce the risk of prostate surgery. Gold Standard reports that Proscar may also slow the progression of BPH when used with certain other medications.

Study Results for Avodart and Proscar in Preventing Prostate Cancer

GlaxoSmithKline provided results of the four-year study titled Reduction by Dutasteride of Prostate Cancer Events (REDUCE). Merck provided results of the seven-year study PCPT. The FDA's ODAC Briefing Statement contains detailed results of each study. Relevant to both studies is the fact that African American men were under-represented as to general population density. This is significant because that demographic has a higher risk of developing prostate cancer.

The PCPT study revealed that Proscar did reduce the incidence of low-grade prostate cancer tumors (less-aggressive tumors and generally non-life-threatening) compared to the placebo group. However, after seven years of daily Proscar use, the men in the study had slightly higher incidences of high-grade prostate cancer tumors. The REDUCE study provided similar findings after four years of daily Avodart use.

Bottom Line

There are many variables to be weighed by the FDA before it can conclude that these medications are prostate cancer prevention aids. The FDA reports the two central issues under determination are: 1) Do the trial results "provide evidence of a clinically meaningful benefit?" and 2) Do the risks outweigh the benefits?

Sources: "FDA Reviews 2New Drugs to Reduce Prostate Cancer," CBS News, Nov. 30, 2010.
Dutasteride Oral Capsule, Gold Standard.
Finasteride Oral Tablet, Gold Standard.
ODAC Briefing Document, U.S. Food and Drug Administration, Dec. 1, 2010.