By Jim Shrine

NeXstar Pharmaceuticals Inc. released preliminary Phase II data showing its liposomal amikacin performed as well as standard therapies in urinary tract infections (UTIs), and did so as a single dose and without side effects.

None of the patients receiving a single dose of MiKasome had recurring infection 36 days after treatment, although 30 percent to 50 percent of those undergoing the standard one or two weeks of treatment historically showed recurrence within that time frame.

The 71-patient trial included four doses and schedules. One regimen was 10 milligrams per kilogram of body weight daily for seven days. The others were single doses of 40 milligrams per kilogram of body weight; two grams; or three grams.

A clinical investigator at the University of Washington, in Seattle, said all clinical signs of UTI resolved in 50 percent to 78 percent of patients treated, which is consistent with results from the best current treatments. The investigator, John Krieger, presented the data at the European Congress of Clinical Microbiology and Infectious Diseases, in Berlin. Final results are expected to be released later this year.

Katy Doherty, NeXstar¿s manager, corporate communications, said single dosing would be an advantage in ensuring patients complete their treatment. MiKasome also did not produce side effects, such as hearing loss and kidney impairment, that are seen with conventional amikacin.

Phase II Program Expanding

Doherty said NeXstar is expanding the Phase II MiKasome program in a 165-patient study started a week ago. There will be 55 patients in each of three fixed-dose arms: .75 grams ; 1.5 grams; and three grams . Endpoints are microbiological and clinical cure rates.

NeXstar¿s stock price has been tied to that of Gilead Sciences Inc., of Foster City, Calif., since the March 1 news that Gilead would acquire NeXstar. (See BioWorld Today, March 2, 1999, p. 1.)

Gilead fell significantly Monday, and NeXstar (NASDAQ:NXTR) did, too. NeXstar dropped 13 percent, or $2.687, to close at $17.812. Gilead (NASDAQ:GILD) was downgraded Monday by at least two firms ¿ Merrill Lynch and PaineWebber Inc., both of New York ¿ and fell 15 percent, or $8.625, to close at $48.125.

Elise Wang, a first vice president at PaineWebber, said in a research note that Gilead has appreciated nearly 40 percent this year, and was fairly valued at a $1.7 billion market cap. She also noted that regulatory and competitive hurdles still exist for Gilead¿s lead products, Preveon and GS4104.