MARION MERRELL DOW LOOKING AT LOWER SELDANE DOSAGE

MARION MERRELL DOW LOOKING AT LOWER SELDANE DOSAGE and the development of an "acid metabolite" of the nonsedating antihistamine as two "possible options" for bringing the prescription drug over the counter, Exec VP and Chief Financial Officer Edward Mehrer told the Mabon Securities Research Conference Dec. 2 in New York City. MMD's development plans for OTC Seldane (terfenadine) stumbled when reports of cardiotoxicity associated with the prescription drug led FDA in July to ask the company to add a boxed warning to labeling and send out over 900,000 letters to health professionals ("The Pink Sheet" July 13, p. 9). A lower-dose version of Seldane for the OTC market "is one of the options we are considering," Mehrer said, but MMD does not "know for sure how viable" that approach would be. The acid metabolite is a "chemical variation of the drug that could avoid the possible [cardiovascular] side effects" of terfenadine because "it would bypass the liver" where terfenadine is metabolized, Mehrer said. He noted that patients who suffered cardiac side effects while on Seldane "tended to have a metabolism impaired by liver disease, or other drugs inhibited the liver's ability to metabolize Seldane." The metabolite has not been tested in humans and would require a full NDA to gain approval, Marion Merrell Dow said. Regarding the options the company is reviewing for terfenadine, "it will be a few months before we really have a clear direction of what the prospects are," Mehrer said. MMD is "actively engaged in a scientific review with FDA and its outside experts which we believe will clarify the cardiovascular profile of Seldane," Mehrer added. Leonard Bernstein, MD, an MMD consultant, told a Nonprescription Drug Manufacturers Association conference in September that an analysis of the adverse event data shows the majority of cardiovascular side effects reported with prescription Seldane to be associated with known risk factors. From a retrospective analysis, he concluded that terfenadine is "as safe as ibuprofen" and safer than diphenhydramine ("The Pink Sheet" Sept. 21, T&G-2). Marion Merrell Dow is emphasizing the potential for direct-to- consumer ads to turn around falling Seldane sales. Market research has shown "that the major effect of the negative publicity" about Seldane's potentially fatal drug interactions with erythromycin and two antifungals "has been on the consumers," Mehrer said, adding "physicians and pharmacists had a better understanding" about the problem when the news broke in July. After the relabeling, worldwide Seldane sales dropped during the third quarter by 7% to $199 mil. following a 31% growth in sales through the first six months of 1992. Through nine months, Seldane sales were ahead for the year by 17%, at $700 mil. ("The Pink Sheet" Oct. 26, p. 10). Marion Merrell Dow has "initiated an active consumer education effort working with the news media aimed at rebuilding confidence in the Seldane brand," Mehrer said. The company is working with FDA to develop "plain English brochures and direct-to-consumer communications" as part of that effort. MMD's patient information program was delayed due to the Sept. 11 approval of Janssen's antifungal Sporanox (itraconazole) when the company had to add itraconazole interaction data to labeling and patient packet inserts. Speaking of another potential Rx-to-OTC switch candidate, Carafate (sucralfate), Mehrer said: "The big issue there is trying to identify what indication we ought to be going for and we haven't come to a conclusion on that." MMD has a codevelopment agreement with Schering-Plough for the product. Mehrer highlighted three drugs MMD recently has launched in European markets that the company "expects to become major products over the next few years, particularly after they reach the U.S. market." Targocid (teicoplanin), an antibiotic for gram positive infections "can be given as a once-a-day injection so that instead of keeping a patient in the hospital for several days ...the doctor sends the patient home," Mehrer said. MMD filed an NDA for Targocid in March 1991. MMD will submit an NDA for its Sabril (vigabatrin) epilepsy treatment "in 1993," Mehrer said. The drug, which "has been rolled out in several European countries" in 1992, "provides relief from seizures for many patients who do not get control from their present medications," the MMD exec said. Deflazacort, a steroid for the treatment of "asthma, rheumatoid arthritis and other inflammatory diseases," is in Phase III trials and an NDA filing is planned "for the early 1995 time frame."