SAN DIEGO, CA - (November 1, 1999) - Privately-held Structural Bioinformatics Inc. ("SBI") of San Diego, California announced today that its computational prediction of the mode of action of inhibitors of a novel human viral enzyme has been validated experimentally.

In an ongoing collaboration, BioChem Pharma (Nasdaq: BCHE; Toronto, Montreal: BCH) scientists determined that the NMR structure of an enzyme-inhibitor complex agreed very well with models of an inhibitor-complex previously computationally predicted by SBI using the enzyme structure modeled from its gene sequence. While x-ray crystallographic structures of enzyme-inhibitor complexes have been previously used by a number of pharmaceutical companies for structure-based enzyme inhibitor design, protein structure determination by x-ray crystallography can unpredictably take many months to many years. In the past, however, modeled protein structures, which could be generated much more rapidly, yielded surface-structural information of insufficient accuracy to permit direct use in structure-based drug design. "The use of highly refined 3D-protein structural models, generated in a matter of days, and made possible by SBI's proprietary computational methods, has overcome the limitations of long timeframes and surface-structural inaccuracies demonstrated by x-ray crystallography and earlier modeling techniques, respectively, greatly speeding the structure-based drug design process for novel drug targets for which no x-ray structures are yet available," said Dr. Edward Maggio, SBI's Chairman, President and Chief Executive Officer.

SBI entered into its initial collaborative agreement with BioChem in August of 1997 aimed at the discovery of drugs for certain viral and cancer targets. Technical success triggered a previously announced milestone payment. SBI and BioChem Pharma entered into a second collaboration agreement in May of 1999.

BioChem Pharma is an international biopharmaceutical company dedicated to the research, development and commercialization of innovative products for the prevention and treatment of human diseases with a focus in the anti-infective and anticancer areas.

Structural Bioinformatics is a world leader in computational proteomics - the study of the structural properties of proteins using mathematical algorithms. The Company has developed proprietary algorithms to generate three-dimensional structural models of proteins from primary gene sequence data, and to perform primary drug discovery screening in silico. SBI offers two subscription database products. The first, SBdBase^TM, is composed of thousands of structural models of proteins from more than 150 distinct families, which promises to accelerate lead optimization and rational drug design. The second is SVdBase^TM, a series of databases each containing structural models generated from genetic variations in a single, medically important gene, such as HIV reverse transcriptase, which promise to enable better target selection and optimize drug design. Its partner in generating HIV SVdBases is Quest Diagnostics, Inc. SBI also employs its technologies in collaborative R&D programs. Current partners include DuPont Pharmaceuticals Company, BioChem Pharma Inc. and Yamanouchi Pharmaceutical Co., Ltd.