BOEHRINGER INGELHEIM CLOSE TO ONCE-A-WEEK ANTIHYPERTENSIVE, CATAPRES-TTS: CLONIDINE IN ALZA SYSTEM IS APPROVABLE; COULD REACH MARKET BEFORE END OF YEAR

Boehringer Ingelheim's once-a-week transdermal Catapres-TTS is "approvable," the company announced in a Sept. 5 press release jointly issued with Alza. The transdermal formulation of Boehringer's antihypertensive Catapres (clonidine HCl) was developed under a joint agreement with Alza, using Alza's patch drug delivery technology. Boehringer will market Catapres-TTS; Alza will manufacture the product and collect royalties on sales. According to the Sept. 5 release, Boehringer expects to begin marketing the drug "later this year or in the first quarter of 1985." FDA notified the firm of the "approvable" status of Catapres-TTS in an Aug. 30 letter, a company spokesman said. Boehringer filed an NDA for the seven-day antihypertensive in November 1982. The U.S. appears to be ahead as the first regulatory clearance for the transdermal patch form of clonidine. Catapres-TTS will be the third transdermal product using the Alza system. The other transdermal products employing Alza's technology are marketed by Ciba-Geigy, Transderm-Nitro and Transderm Scop. The Catapres-TTS approval is important to Alza as an extension of its joint venture base beyond work with Ciba-Geigy and as a visible sign of continuing Alza development activity. Alza has had difficulty in recent months clearing regulatory hurdless for its Oros oral sustained release system. One Merck product, Indosmos, was dropped due to adverse reaction concerns raised overseas. A Ciba-Geigy OTC diet aid using the oral release system, Acutrim, has come under FDA scrutiny because the agency believes the product may need a new drug approval. In studies involving 85 patients, transdermal clonidine was found to have a 60% effectiveness rate in patients with mild to moderate essential hypertension, University of California physician M. A. Weber reported at the Second World Conference on Clinical Pharmacology and Therapeutics last summer ("The Pink Sheet" Aug. 8, 1983, T&G-1). Although researchers have reported that the side effects associated with Catapres-TTS are less severe than those found in clonidine oral administration, one side effect peculiar to the transdermal system is a dermatological change that developed under the patches of seven patients. Moving the patches, or discontinuing treatment prevented rashes. Boehringer also has an NDA in the late stages of review at FDA for its bronchodilator Berotec (fenoterol hydrobromide). The firm currently has NDAs pending for another three drugs -- the bronchodilator Atrovent (ipatropium bromide), the anti-arrhythmic Mexitil (mexiletine) and the sedative-hypnotic Lendorm (brotizolam). Boehringer plans to file an NDA for its antipeptic ulcer agent Gastrozepine (pirenzepine) in the near future.