BOEHRINGER INGELHEIM R&D EARNS FIRST U.S. NCE APPROVAL IN 11 YEARS, MEXITIL; PRODUCT IS THIRD ANTI-ARRHYTHMIC APPROVED BY FDA DURING 1985

Boehringer Ingelheim's Mexitil (mexiletine HCl) is the firm's first new chemical entity (NCE) approval since the 1974 approval for Catapres (clonidine) over 11 years ago. Mexitil, approved Dec. 30, is indicated "for the suppression of symptomatic ventricular arrhythmias, including frequent premature ventricular contractions, unifocal or multifocal, couplets and ventricular tachycardia," according to the FDA-approved labeling. The NDA for the drug was initially submitted in September 1982. Mexitil was classified by FDA as a 1b drug, a new chemical entity representing a modest therapeutic gain over existing therapies. The firm said it will begin distribution of the new anti-arrhythmic "around the first of April." The product will be supplied in bottles of 100 and unit-dose individual blister-sealed capsules of 150 mg, 200 mg, and 250 mg in cartons of 100. The price to whslrs. is $26.78, $31.93, and $37.08, respectively, for the three dosage strengths. Labeling notes that Mexitil has "electrophysiologic properties in man similar to those of lidocaine, but dissimilar from quinidine, procainamide, and disopyramide." Discussing controlled comparative trials, the labeling states that "Mexitil, at doses of 200-400 mg q8h produced a significant reduction of ventricular premature beats, paired beats, and episodes of non-sustained ventricular tachycardia compared to placebo and was similar in effectiveness to the active agents . . . quinidine, procainamide and disopyramide." FDA's Cardio-Renal Drugs Advisory Cmte. recommended approval of Mexitil in June 1984 "for the treatment of symptomatic ventricular arrhythmias." Explaining why the cmte. limited its recommendation to symptomatic arrhythmias, cmte. reviewer Raymond Woosley, MD/PhD, Vanderbilt University said: "Until studies are performed to address mortality, the use of these agents in treatment of asymptomatic PVCs (premature ventricular contractions) for patients at risk of malignant arrhythmias, without history of symptomatic arrhythmias, is unjustified at this point in time." The approval of Mexitil comes at a timely point for Boehringer Ingelheim. Catapres will begin to face generic competition when its marketing exclusivity expires in July 1986. The generic mfr. Par already has a delayed approval for clonidine. Boehringer's introduction of Catapres TTS (clonidine in a transdermal patch delivery system) in September along with the approval of a new patent protected NCE will help to make up for business lost to generic clonidine products.