Sequus Pharmaceuticals' AMPHOTEC product significantly more effective than amphotericin B and Abelcet in treating cryptococcus infection in murine model.

MENLO PARK, Calif.--(BUSINESS WIRE)--April 1, 1997--SEQUUS Pharmaceuticals, Inc. (Nasdaq:SEQU) today announced results of a preclinical study comparing AMPHOTEC(TM) to amphotericin B and to alternative lipid-based formulations of amphotericin B. The study was conducted at the California Institute for Medical Research, Santa Clara Valley Medical Center, and Stanford University by Drs. Karl Clemons and David Stevens. In this study, AMPHOTEC, amphotericin B, Abelcet(TM) and AmBisome(R) were compared in a murine model of Cryptococcus neoformans infection. The results of this study show that AMPHOTEC was significantly more effective than either amphotericin B or Abelcet and that AmBisome was approximately equivalent to AMPHOTEC.

"Since it has not been possible to conduct comparative human clinical trials with the other lipid-based amphotericin B formulations, preclinical data provides valuable insight into the comparative efficacy of these agents," said I. Craig Henderson, M.D., Chairman and CEO. "The results of this study confirm our belief that AMPHOTEC provides the best combination of clinical benefit and value."

This Cryptococcus neoformans fungus used in the study is quite difficult to treat and is often fatal in certain patient populations. Thus, C. neoformans provided a formidable challenge to the drugs included in the study as well as an opportunity for comparing the relative efficacy of the study drugs. Data from the Stanford study show that at the minimum dose, 50% of the AMPHOTEC-treated subjects survived as compared to 10% for amphotericin B, 20% for Abelcet, and 30% for AmBisome (survival data were collected on day 49). AMPHOTEC was somewhat more effective than AmBisome (difference not statistically significant) and significantly better than Abelcet and amphotericin B in clearing fungus from affected tissues. Five times as much Abelcet was required to achieve the effect of AMPHOTEC in eradicating fungal infection and improving survival in the test subjects. The survival rates observed in this study are presented on the following page.

AMPHOTEC has been cleared to market in the United States for the treatment of invasive aspergillosis in patients where renal impairment or unacceptable toxicity precludes the use of amphotericin B in effective doses and in patients with invasive aspergillosis where prior amphotericin B therapy has failed. In Europe and certain Asian and South American countries, AMPHOTEC has been approved for the treatment of severe systemic and/or deep mycoses in patients for whom conventional amphotericin B therapy cannot be used in effective doses due to toxicity or impaired renal function or in patients who have failed conventional systemic antifungal therapy.

AMPHOTEC has not been approved in the United States for treating cryptococcus and SEQUUS is not promoting its use for this indication. -0-

Preclinical Results from Study Comparing AMPHOTEC with amphotericin B,
              Abelcet and AmBisome in Murine Model of Cryptococcus


Treatment                        Dose (mg/Kg)   % Surviving (day 49)

Placebo                              -                  10%

Conventional Amphotericin B          1                  10%

AMPHOTEC                             1                  50%
                                     5                 100%
                                    10                 100%

Abelcet                              1                  20%
                                     5                  50%
                                    10                  90%

AmBisome                             1                  30%
                                     5                 100%
                                    10                 100%

Conventional Amphotericin B was not dosed above 1 mg/kg due to known toxicities.

Established in 1981 and headquartered in Menlo Park, Calif. (with offices in London, England), SEQUUS is developing and commercializing lipid-based biopharmaceutical products primarily to treat cancer and infectious diseases. Information about SEQUUS is available on the internet at http://www.sequus.com.

CONTACT: SEQUUS Pharmaceuticals, Inc. Ogilvy Adams & Rinehart

I. Craig Henderson, M.D. (Media Inquiries)

Chairman and CEO Susan Eckstein 212/880-5207

Scott Minick

President and COO Burns McClellan

Donald J. Stewart (Investor Inquiries)

VP, Finance & Treasurer Ruth Markowitz 212/505-1919

415/323-9011