Press Release Details

BIOCRYST PHARMACEUTICALS ANNOUNCES PRELIMINARY PHASE II RESULTS FROM WORLDWIDE INFLUENZA COLLABORATION WITH JOHNSON & JOHNSON

Birmingham, Ala. – August 24, 1999 – BioCryst Pharmaceuticals, Inc. (Nasdaq: BCRX) today announced preliminary results from a Phase II clinical study of RWJ-270201, a neuraminidase inhibitor, conducted by the R.W. Johnson Pharmaceutical Research Institute (PRI), a Johnson & Johnson (NYSE: JNJ) company.

PRI conducted a Phase II placebo-controlled randomized study of healthy volunteers infected with a susceptible strain of Influenza A and has provided preliminary results to BioCryst. The primary efficacy endpoint was the reduction in viral titers in infected subjects. Preliminary results showed a statistically significant result for the primary endpoint and evaluation of safety showed that the drug was well-tolerated at all dosage levels. These results are preliminary only and subject to further analysis.

Under the agreement with BioCryst, PRI has full responsibility for and control of all aspects of further development of the compound, including the timing and design of any further trials. BioCryst may receive undisclosed cash payments upon achievement of specified developmental and regulatory milestones.

PRI will be responsible for research and development of the compounds, including expenses. Ortho-McNeil Pharmaceutical, Inc. will market products cleared for marketing in the U.S.; Janssen-Cilag and other Johnson & Johnson companies will market products cleared for marketing outside the U.S. BioCryst will receive undisclosed royalties on sales of any products marketed under the agreement.

"BioCryst is pleased that the preliminary Phase II results reflect positive activity of the compound," said Charles E. Bugg, Ph.D., Chairman and CEO of BioCryst. "These results enhance our confidence that Johnson & Johnson is an ideal partner."

Influenza Background

Influenza, commonly known as the flu, is perceived by many people as a transient, inconvenient viral infection that leaves its sufferers bedridden for a few days. In truth, however, it is a virulent, sometimes deadly disease that affects up to 20 percent of the U.S. population (approximately 20 to 40 million people) each year and an estimated 120 million people in North America, Western Europe and Japan combined. People over age 65 can be especially susceptible to influenza infections.

During flu pandemics, which occur approximately every 10 years, highly virulent strains of the virus are responsible for significant morbidity and mortality. The worst known influenza pandemic occurred in 1918 and was estimated to have caused 700 million cases of flu and 20 million deaths worldwide.

The development of effective therapeutics has been challenging for medical researchers due to the seasonal variation in viral strains and the highly infectious nature of influenza. While flu vaccines have had some success in preventing disease caused by strains of the virus, there are currently no effective means to treat established influenza infection, nor are the influenza vaccines universally useful or preventative.

Company Background

Founded in 1986, BioCryst Pharmaceuticals, Inc. designs and develops novel small-molecule pharmaceuticals using structure-based drug design, an approach to drug discovery that integrates advanced biology, biophysics and medicinal chemistry. The Company is targeting T-cell, viral, and cardiovascular diseases and disorders, which include cutaneous T-cell lymphoma, HIV influenza and cardiopulmonary bypass surgery.

This press release contains projections or other forward-looking statements regarding future events or the future financial performance of the Company. These statements are only predictions and the actual events or results may differ materially. Some of the factors that could affect the forward-looking statements contained herein include, without limitation, that there can be no assurances that PRI’s, the Company’s collaborative partner’s, research or product development efforts as to the influenza neuraminidase inhibitors will be successfully completed, that any Phase III clinical results will show statistical significance and will not show negative safety characteristics, that the agreements with PRI will not be terminated according to their terms, that research and testing will result in milestone or royalty payments under the agreements with PRI, and there can be no assurance as to timing by which products will be cleared for marketing, that the compounds currently under development will be safe or efficacious, or that required regulatory clearances can be obtained from the U.S. Food and Drug Administration. Please refer to the documents BioCryst files from time to time with the Securities and Exchange Commission, specifically BioCryst’s most recent Form 10-K and Form 10-Q. These documents contain and identify important factors that could cause the actual results to differ materially from those contained in the projections or forward-looking statements.