Liposome Technology Inc. (LTI) announced Wednesday that ithas countersued Vestar Inc. over a patent on making lipid-formulated amphotericin B.

LTI of Menlo Park, Calif., was awarded U.S. patent No.5,180,713 on a method of preparing a stable liposome-entrapped amphotericin B in January. Vestar of San Dimas,Calif., sued LTI the following day, Jan. 20, asking the DelawareFederal Court to declare that LTI's patent is invalid,unenforceable and not infringed by Vestar's productAmBisome.

LTI's countersuit, filed March 26, asks the court to declare itspatent valid and enforceable, and to deny Vestar's claim ofnon-infringement. LTI also requested a change of venue fromDelaware (where both companies were incorporated) to the U.S.District Court for the Northern District of California.

"This provides an early opportunity to clarify the futurecompetitive environment for LTI's Amphocil product in the U.S.and to affirm LTI's intellectual property rights regardingliposomal amphotericin B formulations," said Peter Leigh, LTI'svice president and chief financial officer. "We decided to seizethe opportunity sooner rather than later," Leigh told BioWorld.

Even though LTI isn't using the newly patented method toproduct its amphotericin B drug, Amphocil, it believes that thepatents "may pose a barrier to competitors making or selling aliposome-entrapped amphotericin B formulation in the U.S."

Liposome Technology's stock (NASDAQ:LTIZ) closed Wednesdayat $7.25 a share, up 63 cents; Vestar's stock (NASDAQ:VSTR)closed at $11.25 a share, down 13 cents. -- Jennifer Van Brunt

(c) 1997 American Health Consultants. All rights reserved.

No Comments