MEDICAL THERAPY OF PROSTATIC SYMPTOMS (MTOPS)
Principal Investigator: Pamela Katzen Burrows, M.S.
Principal Investigator: Oliver M. Bautista, Ph.D.
Enlargement of the prostate is a common part of a man's aging process. The prostate gland is in a process of continual growth through most of a man's adult life. Medical doctors refer to the condition of having an enlarged prostate as benign prostatic hyperplasia (BPH), or benign prostatic hypertrophy. Though prostate enlargement is an ongoing process, it does not usually present problems until late in a man's life. Many of the problems that occur as a result of BPH can be attributed to the obstruction of the urethra and loss of bladder function, two conditions that are directly related to the enlargement of the prostate. There are various symptoms of BPH, but the common ones involve changes or problems with urination.
Treatment options available to men who have BPH symptoms fall into three general categories: surgical, non-surgical, and drug therapy. The U.S. Food and Drug Administration (FDA) has approved four drugs for the treatment of BPH. These drugs alleviate the symptoms of BPH by relieving the obstruction of the urethra.
Finasteride ( Proscar (R) ), a 5(alpha)-reductase inhibitor, was approved by the FDA in 1992. Finasteride inhibits the production of hormones that causes the enlargement of the prostate. Finasteride can also shrink the prostate in some men.
Three other FDA-approved drugs belonging to the class of drugs known as alpha-blockers relieve BPH symptoms by relaxing the smooth muscle of the prostate and the bladder neck. Terazosin (Hytrinÿ) was approved by the FDA in 1993, doxazosin ( Cardura (R) ) in 1995, and tamsulosin (Flomaxÿ) in 1997.
The Medical Therapy of Prostatic Symptoms ( MTOPS) was a multi-center clinical trial designed to assess the long-term benefits of pharmacotherapy of BPH. MTOPS was a double-masked, placebo-controlled randomized clinical trial designed to evaluate the long-term efficacy of finasteride, or doxazosin, or the combination of both, in delaying or preventing the clinical progression of symptomatic BPH. MTOPS was the largest and longest study to test whether drug therapy can prevent or delay the noncancerous growth of the prostate.
The George Washington University Biostatistics Center serves as the Biostatistical Coordinating Center (BCC) of the MTOPS trial.
A limited six-center randomized clinical trial was conducted during 1992-95 in 141 participants with symptomatic BPH to determine the feasibility of conducting a full-scale trial. Upon successful completion of the feasibility phase, the full-scale trial was initiated with 17 US clinical sites participating. From December 1995 through March 1998, the 17 MTOPS clinics enrolled 2,931 participants with a diagnosis of symptomatic BPH.
Participants were randomized to one of four treatment groups: double-placebo, finasteride, doxazosin or the combination of finasteride and doxazosin. A total of 3,047 participants randomized during the pilot and full-scale phases are currently being followed with quarterly visits. Follow-up phase of the full-scale trial will continue until the end of November 2001. Closeout and analysis phase will commence immediately after the last follow-up visit is completed and is projected to last until the first quarter of the year 2002.
Unique feature of MTOPS that has not been done in prior studies of pharmacotherapy of BPH is the biopsy substudy. A total of 1,082 volunteers from the 2,931 participants randomized during the full-scale phase are currently participating in this substudy. Biopsies of the prostate will be obtained on these volunteers at predetermined times during the course of the trial to evaluate the status of the prostate at key event times. The purpose of the substudy was to provide additional information regarding the histopathobiology of BPH and to test existing biomarkers for their prognostic ability regarding response to drug therapy.
Funding for MTOPS NIH/NIDDK (UO1-DK-46472; IND 43,564).
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