MERCK FILES PROSCAR NDA FOR BENIGN PROSTATIC HYPERTROPHY (BPH)

MERCK FILES PROSCAR NDA FOR BENIGN PROSTATIC HYPERTROPHY (BPH) on April 15. The NDA filing in the U.S. is the first for Merck's Proscar (finasteride). Merck, which announced the filing April 16, plans to register the drug for approval in all major markets this spring. The NDA is for a 5 mg tablet to be taken once a day. Finasteride is the first of the 5-alpha reductase inhibitor class of drugs that works by blocking the conversion of testosterone into dihydrotestosterone and is yet another of Merck's new chemical entity NDAs to go to FDA on schedule. The drug will compete with the other potential treatment for BPH, alpha blockers, such as Pfizer's Cardura and Abbott's Hytrin, in a market put by some industry observers at more than $ 1 bil. a year. Benign prostate enlargement is a chronic age-related condition that is estimated to affect 60% of men over 50. The NDA for Proscar contains two pivotal 12-month studies on more than 1,600 patients at 76 centers worldwide that were completed in the summer of 1990. Merck said that the studies demonstrate that Proscar is "generally well tolerated and showed significant prostate regression in a majority of patients, with patients experiencing significant clinical improvement in both urinary flow and symptoms associated with BPH." The NDA will be reviewed by FDA's Endocrinologic & Metabolic Drugs Advisory Committee where Merck has had previous success with its Mevacor NDA. The MS&D Phase III clinical trial data will be presented at the American Urologists Association meeting June 2-6 in Toronto. Although the company is not disclosing the clinical results until the AUA meeting, Merck Chairman Roy Vagelos, MD, discussed some of the data at a November presentation to securities analysts ("The Pink Sheet" Nov. 19, p. 8). Vagelos said that the "significant" prostate shrinkage seen in the trials translated into "20% shrinkage or greater" and that "improvement" in BPH symptoms translated into an average peak urinary flow increase of 3 cc per minute over a baseline of less than 15 cc/min. Vagelos also touted the drug's safety profile and "excellent tolerability." However, he acknowledged that Proscar does not provide immediate relief, which may mean several months of treatment before improvement is seen in some patients. Under the joint venture agreement between Merck and DuPont, finasteride will be co-marketed by DuPont Merck Pharmaceuticals in Germany, France, Italy, Spain and the U.K. under a different brandname. Merck will market the product in the U.S.