Schering/Zonagen end Vasomax agreement
Executive Summary
Schering-Plough and Zonagen mutually terminate worldwide licensing agreement for experimental oral erectile dysfunction therapy Vasomax and other phentolamine-based technologies, Zonagen announces July 15. The decision coincides with the submission of final results from a one-year mechanistic study of phentolamine-induced brown fat proliferations in rats, which Zonegan maintains show no effect. The study was designed to allay FDA's concerns raised by an earlier two-year rat carcinogenicity trial; FDA deemed Vasomax "not approvable" in May 1999 and subsequently placed the drug on clinical hold (1"The Pink Sheet" Aug. 16, 1999, p. 32)...