KANSAS CITY, SAN DIEGO, and FRANKFURT, Germany, Jan. 12, 1996 -- Hoechst Marion Roussel and Alliance Pharmaceutical Corp. (Nasdaq: ALLP) today announced an agreement in principle for a worldwide license to develop and market LiquiVent (perflubron), a potential new drug in pivotal Phase II/III trials for treatment of acute respiratory failure. Hoechst Marion Roussel is the global pharmaceutical division of Hoechst AG.

LiquiVent is a biologically inert, oxygen-carrying liquid that is administered directly into the lungs of patients undergoing mechanical ventilation. It is intended for use in the treatment of acute respiratory distress syndrome (ARDS), which affects patients of all ages. Respiratory distress is caused by factors such as infection, traumatic shock, severe burns, inhalation of toxic substances, and conditions associated with premature birth.

Pivotal Phase II/III trials with pediatric patients were begun recently, and Phase II studies with adults and premature infants are ongoing. Previously completed Phase I/II clinical trials demonstrated the safety of LiquiVent and showed improvement in both respiratory gas exchange and lung mechanics.

"LiquiVent is a promising new approach for patients with acute respiratory distress, a life-threatening condition that often requires costly, extended hospitalization in intensive care units," said Jean- Pierre Godard, head of Hoechst Marion Roussel. "This agreement with Alliance represents a significant addition to Hoechst Marion Roussel's franchise in respiratory medicine, with another important product in our development pipeline."

"We look forward to a working relationship with Hoechst Marion Roussel, a company with a strong worldwide presence and commitment to respiratory products," said Duane J. Roth, Chairman, President and CEO of Alliance. "We feel that they are an ideal partner in the effort to commercialize LiquiVent."

The transaction is conditional upon the negotiation and execution of a definitive agreement for the license, which the companies expect to finalize within 60 days, and is subject to applicable regulatory approvals. Financial terms of the proposed agreement were not disclosed.

The license agreement is expected to provide for Hoechst Marion Roussel to purchase a minority equity interest in Alliance and to pay Alliance a license fee and other payments upon achieving certain development milestones. Hoechst Marion Roussel would have exclusive manufacturing and worldwide marketing rights to the product. Hoechst Marion Roussel would fund product development activities and pay a royalty to Alliance on sales of LiquiVent following commercialization.

Alliance is a pharmaceutical research and development company focusing on transforming novel scientific discoveries into innovative drug products. In addition to LiquiVent, Alliance is developing an intravascular oxygen carrier for use as a temporary "blood substitute" to reduce or eliminate the need for allogeneic (donor) blood transfusions during elective surgery, and an intravenous contrast agent for enhancement of ultrasound images to detect blood flow abnormalities.

Hoechst Marion Roussel, a world leader in pharmaceutical-based health care, is dedicated to extending and enhancing human life through the discovery, development, manufacture and sale of pharmaceutical products. Hoechst Marion Roussel is a member of the Hoechst Group, has its global headquarters in Frankfurt, Germany, and its North American headquarters in Kansas City, Mo.

CONTACT: David M. Thompson, or Richard M. Johnson, of Hoechst Marion Roussel, 816-966-5000; or Gwen Rosenberg of Alliance Pharmaceutical Corp., 619-558-4300/ (ALLP)