BERLEX' BETAPACE SIGNIFICANTLY REDUCES RISK OF ARRHYTHMIA RECURRENCE, ESVEM TRIAL DATA INDICATE; RESULTS SHOULD CLEAR WAY FOR FDA APPROVAL - RESEARCHER

Sotalol (Berlex' Betapace) significantly reduces the risk of ventricular arrhythmia recurrence, according to data presented at the American College of Cardiology's annual meeting in Dallas. FDA's Cardiovascular and Renal Drugs Advisory Committee recommended Betapace for approval in late 1990, conditioned on the outcome of the Electrophysiology Study Versus Electrocardiographic Monitoring for Selection of Antiarrhythmic Therapy of Ventricular Tachyarrhythmias, or ESVEM trial ("The Pink Sheet" Dec. 17, 1990, p. 21). The trial was sponsored by the National Heart, Lung and Blood Institute. Results from the ESVEM study should clear the way for a rapid approval of Betapace by FDA, Jay Mason, MD, University of Utah, and principal investigator of the study, predicted at an April 14 press briefing. Betapace was developed by Bristol-Myers Squibb, and marketing rights were licensed to Berlex parent Schering AG in exchange for rights to the tumor imaging agent ProHance ("The Pink Sheet" Dec. 2, 1991, T&G-1). "Given the striking performance of sotalol in this study, I suspect that FDA will move quickly to consider the approval of this drug," Mason said. FDA "wanted to wait until these results were available before making a decision," he noted. Begun in October 1985 and completed in February of this year, the ESVEM study explored the efficacy of six antiarrhythmic agents in treating patients with life-threatening ventricular arrhythmias. The drugs tested in the trial included sotalol, Boehringer Ingelheim's Mexitil (mexilitene); Knoll's Rythmol (propafenone) and generically available quinidine gluconate and procainamide. Another investigational drug, Warner-Lambert's Pimavar (pirmenol), was also tested. In the trial, 486 patients were given standard doses of each of the six drugs in random sequence until one drug was found to be effective. Sotalol was administered at a dose of 320 mg per day. Efficacy was defined as suppression of spontaneous ventricular arrhythmias during treadmill testing in the case of patients undergoing Holter monitoring or suppression of inducible ventricular arrhythmias of more than 15 beats in those patients in the electrophysiology testing arm. Patients were tested at one, three, and six months after discharge and every six months thereafter. At one year into treatment, sotalol was the only drug that significantly reduced the risk of patients experiencing further ventricular arrhythmias. The arrhythmia recurrence rates for patients receiving sotalol was 21% compared to 44% for patients who received any of the other drugs. Sotalol also reduced all-cause mortality over the six-year period when compared to the other agents, Mason said. Mason speculated that the superiority of sotalol in this study may be due to its combination of beta blocking and Class III antiarrhythmic effects. These effects "probably played a role in the ability to control arrhythmias," Mason said. In addition, sotalol "was in the lower half of the group in terms of the frequency of adverse events," Mason noted. However, sotalol's incidence of proarrhythmia was not appreciably different than the other drugs, Mason said.