STERLING WINSTROL (STANOZOLOL) NDA WITHDRAWAL PROCESS BEGINNING, FDA
Executive Summary
STERLING WINSTROL (STANOZOLOL) NDA WITHDRAWAL PROCESS BEGINNING, FDA announced in an April 23 Federal Register notice. In the notice the agency offered an opportunity for a hearing on the anabolic steroid's two labeled indications, adjunctive treatment of "senile and postmenopausal osteoporosis" and use in raising hemoglobin levels in aplastic anemia patients. The document also revoked the "temporary exemption" that has permitted the drug to remain marketed beyond the initial time limits set for the DESI review. FDA explained that it agreed with the conclusions of its Endocrinologic & Metabolic Drugs Advisory Cmte., which last year declined to recommend approval for either indication ("The Pink Sheet" Sept. 26, T&G-1 and May 23, T&G-2). In January of this year, the cmte. reviewed the drug for use in vascular disorders associated with reduced fibrinolysis and concluded that, while Winstrol favorably influenced biochemical parameters, additional data is needed to establish clinical effectiveness ("The Pink Sheet" Jan. 30, p. 13). Regarding the osteoporosis indication, FDA asserted that the one clinical study, the Chestnut study, submitted by the firm cannot by itself support the claim. FDA pointed out that Sterling does have a second clinical trial underway in the U.K., but that the trial "is not expected to be completed for several years." In the Chestnut study, "although a statistically significant difference between Winstrol and control groups was obtained for total body calcium in the analysis presented by Sterling, this finding is sensitive to the handling of data on patients withdrawn from the study and the method of analysis used," FDA explained. The agency said when dropouts are included in the analysis, the results lose their statistical significance. Further, FDA expressed concern about hepatotoxicity and effects on the cardiovascular system, especially in view of the large patient population. Requests for hearing are due by May 23.