HASSLE’s ONCE-DAILY METOPROLOL CR RECOMMENDED FOR APPROVAL

HASSLE's ONCE-DAILY METOPROLOL CR RECOMMENDED FOR APPROVAL for the treatment of hypertension and angina by FDA's Cardio-Renal Advisory Committee June 14. The panel unanimously supported the use of once-daily metoprolol in doses of 100 to 400 mg for both indications. In addition, the committee voted seven-to-one to recommend approval of Hassle's 50 mg metoprolol for hypertension, but not for angina. AB Hassle, an Astra subsidiary based in Molndal, Sweden, currently markets the once-daily beta-blocker in Europe in 50 mg, 100 mg and 200 mg strengths. The firm provided data that the degree of beta-blockade at 100-400 mg dose levels is similar to that of Lopressor, which Ciba-Geigy markets in the U.S. under license from Hassle. * The committee's favorable review strengthens Hassle's position in ongoing licensing negotiations with Ciba-Geigy concerning Lopressor OROS -- a once-daily metoprolol product developed with Alza. Although Ciba-Geigy received approval for Lopressor OROS last December, the company has not yet introduced the product in the U.S. because of ongoing licensing negotiations with Hassle ("The Pink Sheet" Jan. 22, p. 2). The near-term availability of Hassle's metoprolol CR could be a trump card for Astra if the Swedish company's deal with Ciba-Geigy is nonexclusive, which would make Hassle's metoprolol a serious competitive threat to Lopressor. Hassle submitted data from five European randomized, double-blind crossover studies of metoprolol CR versus immediate release metoprolol (Ciba-Geigy's Lopressor) at different dosing levels. All five studies enrolled healthy males ages 20-35, and measured exercise heart rate after five to seven days' treatment. The variables measured in the studies included minimum effect and maximum effect on heart rate as well as area under the curve over 24 hours. Summarizing the five studies, Hassle's Robert Bergstrand, MD/PhD, said "there was no significant difference in area under the effect curve in any of the studies." The company was not required to submit placebo-controlled efficacy studies. FDA's policy is that a sustained-release formulation of a beta-blocker can be approved for the indications of hypertension and angina if another formulation of the drug is already approved for those indications and the dose and dose-interval of the new formulation are acceptably characterized using beta-blockade (measured as effect on exercise heart rate) as the bioassay. For the 50 mg indication for hypertension, Hassle presented data from three studies of the drug versus placebo, measuring changes in both standing and supine heart rate, diastolic blood pressure and systolic pressure. In each study, metoprolol showed some improvement compared to placebo in some of the variables measured, but not in all variables. The committee voted to recommend approval of the 50 mg dose for hypertension despite criticism from several committee members regarding weaknesses in the design of the studies. Reflecting the committee consensus, panel member Jeremy Ruskin, MD, Massachusetts General Hospital, suggested that the data for the 50 mg dose was "supportive" of use in hypertension.