Executive Summary

SEARLE's "SECOND GENERATION" TPA WILL ENTER CLINICALS by year end, the company announced in a May 12 press release. "Preliminary tests suggest the substance . . . may have substantial advantages over other versions of tissue plasminogen activator currently under study, making it, in effect, a more advanced 'second generation' TPA which could render obsolete those currently in clinical trials," the release asserted. According to Searle, the new compound's advantages include greater potency than other versions of TPA currently under study and a potentially greater specificity for fibrin, a soluble blood protein necessary for the formation of clots. The latter property could allow dissolution of existing clots while avoiding a breakdown of the body's natural clotting mechanism, Searle said. Searle is licensing the recombinant TPA from Invitron, a St. Louis-based biotech company. The agreement, also announced May 12, calls for joint development of the drug, production by Invitron in its million-liter capacity cell culture facility and worldwide marketing by Searle. The new TPA compound was discovered by Monsanto in collaboration with researchers at Oxford University, the release noted. Monsanto, which acquired Searle last October in a $2.7 bil. cash deal, also holds "a major equity position" in Invitron. The development of TPA "is an example of how we expect Monsanto's leadership in biotechnology research to expand the number of pharmaceutical products under development at Searle," Searle Chairman and CEO Sheldon Gilgore, MD, commented. Firms currently engaged in the development of TPA include Biogen, Chiron and Genetics Institute, which have agreements with SmithKline, Hoechst and Burroughs Wellcome, respectively. Furthest along, however, is Genentech, which recently filed an NDA. Genentech said it plans to market the product itself under the trade name Activase.