BOEHRINGER INGELHEIM WILL INTRODUCE CATAPRES-TTS ONCE-WEEKLY PATCH IN EARLY 1985

Boehringer Ingelheim's once-a-week transdermal Catapres-TTS will begin sales in "early 1985," Boehringer and Alza stated in an Oct. 15 joint release announcing FDA approval of the antihypertensive. The U.S. is the first country to approve the transdermal formulation of the antihypertensive, although licenses are reportedly pending in several other countries.

The Catapres transdermal therapeutic system was developed by Alza using Alza's patch delivery drug technology, under a royalty-bearing license agreement with Boehringer Ingelheim's parent, C. H. Boehringer Sohn. Under the agreement, Alza will manufacture the drug and Boehringer will market it. FDA approved the drug within two years of Boehringer's NDA submission in November 1982.

Boehringer will get at least three years of marketing exclusivity in the U.S. for patch clonidine under the recently passed ANDA/Patent Restoration law's provision for a three-year moratorium on abbreviated new drug applications for NDAs that are not new chemical entities, but require clinical trials.

Labeling cautions that "in patients who have developed contact sensitization to Catapres-TTS, substitution of oral Catapres therapy may be associated with development of a generalized skin rash." Adverse reactions with transdermal clonidine are similar to reactions with the oral formulation. Alza noted that the benefits of Catapres-TTS over oral clonidine include increased compliance and a reduction in side effects, since the patient receives less drug. According to the Catapres-TTS labeling, therapy should be initiated with Catapres-TTS-1, which delivers 0.1 mg of clonidine per day. Labeling for the oral formulation calls for initial therapy of 0.1 mg twice a day.

Catapres-TTS-1, Catapres-TTS-2, and Catapres-TTS-3 are supplied as four pouched systems with four adhesive overlays per carton. Labeling notes that "the 3.5, 7.0, and 10.5 cm systems respectively deliver 0.1, 0.2, and 0.3 mg clonidine per day." The whslr. price for the three systems is $36 for 12 (0.1), $60.60 for 12 (0.2), and $28 for 4 (0.3), respectively.