Molecule of dutasteride
The GlaxoSmithKline (GSK) drug Avodart (dutasteride), already approved for treatment in men with enlarged prostate glands, has been rejected by the FDA for the additional indication of reducing the risk of prostate cancer. An FDA advisory panel voted 14-2 on Dec. 1 to recommend against the expanded use of the drug. Roughly 1 million men are currently estimated to be at risk for prostate cancer in the U.S.
Avodart was originally approved by the FDA in 2002 as a treatment for patients with symptomatic benign prostatic hyperplasia (BPH), or “enlarged prostate,” (though it has also been studied as a potential treatment for male pattern baldness). The drug works in part by blocking enzymes that promote prostate growth; it has been shown to relieve symptoms such as frequent and difficult urination, and in many cases eliminates the need for prostate surgery.
Dutasteride has recently undergone clinical trials to determine its efficacy in preventing prostate cancer: The REDUCE trial (http://www.nejm.org/doi/full/10.1056/NEJMoa0908127), a randomized controlled trial of 6,729 men that compared dutasteride to placebo for prevention of prostate cancer, found an overall reduction of 22% in the incidence of prostate cancer over the course of four years. However, the reduction was found only in less fatal prostate cancer subtypes that are often not treated; in the more aggressive subtypes of cancer, there was no reduction seen in the incidence of cancer. Researchers concluded that the use of this drug may delay diagnosis of prostate cancer to the point that the cancer becomes untreatable.
On its site, GSK said that the company has received a complete response letter from the FDA regarding Avodart, which means that the agency needs more information from GSK before it can grant approval. The company did not disclose what steps it will be required to take to gain future approval.