DIPYRIDAMOLE ANDAs/ANDA SUPPLEMENTS WILL REQUIRE IN VIVO STUDIES

DIPYRIDAMOLE ANDAs/ANDA SUPPLEMENTS WILL REQUIRE IN VIVO STUDIES to show bioequivalence to the innovator product (Boehringer Ingelheim's Persantine) for labeling "as an adjunct to coumarin anticoagulants in the prevention of postoperative thromboembolic complications of cardiac valve replacement," FDA told Boehringer Ingelheim in a March 7 letter. "FDA will require that each ANDA and supplemental ANDA for a dipyridamole product bearing the new indication contain a human in vivo bioequivalence study demonstrating that the proposed product has the same rate and extent of absorption as Persantine tablets," FDA said.

* The agency's letter responds to a Dec. 15 petition from the firm requesting that FDA require generic companies to conduct in vivo studies to gain approval for the indication. Boehringer's exclusivity for the cardiac valve replacement indication ran out on Dec. 22.

Although FDA withdrew dipyridamole's angina indication in early 1987, approximately 20 generic companies have continued to market the product on a "conditional" basis while FDA reviews their requests for hearings. Some generic companies, including Duramed, reportedly have already submitted ANDA supplements to gain approval for the cardiac valve replacement indication.