CYTEL TERMINATES PHASE II CLINICAL TRIAL WITH CYLEXIN IN MYOCARDIAL INFARCTION.

SAN DIEGO--(BUSINESS WIRE)--June 5, 1996--Cytel Corporation (NASDAQ: CYTL) announced today the termination of a Phase II clinical study with its cell adhesion blocker, Cylexin(TM). The study was designed to evaluate the effect of the drug on myocardial salvage in patients with acute myocardial infarction treated with primary angioplasty. The Company terminated this study upon recommendation by the independent safety and data monitoring panel. Following a scheduled interim analysis, the panel determined that the drug was safe but, based upon the primary endpoint, there was no benefit in patients treated with Cylexin over those patients in the placebo control group.

Cytel will pursue detailed analyses of all efficacy and safety data from this trial, including those on approximately 30 additional patients from whom data have not yet been collected. The Company previously announced favorable results from a preliminary analysis of a Phase II clinical trial with Cylexin evaluating its ability to reduce reperfusion injury following the surgical removal of chronic blood clots from the lungs in an orphan drug indication, pulmonary thromboendarterectomy (PDE). "When all data from both trials have been fully analyzed, we will evaluate the future strategy for Cylexin with our corporate partners," said Virgil Thompson, President and Chief Executive Officer.

The proprietary technology used to manufacture Cylexin is also applicable to the synthesis of other complex carbohydrates for use in therapeutic or non-therapeutic settings. This technology was the basis for a collaboration with Abbott Laboratories announced earlier this year, whereby Abbott obtained an option to a worldwide license for use of Cytel's technology in the manufacture of carbohydrates for addition to nutritional products. Additionally, in March the Company reported interim data from one of its ongoing Phase II patient studies of Theradigm(TM)-HBV, its novel therapeutic vaccine for the treatment of chronic hepatitis B infection.

Theradigm-HBV caused a HBV-specific CTL (cytotoxic T lymphocyte, or killer T cell) immune response in chronically infected patients and the compound was well tolerated. The data also showed a correlation of CTL induction with biological responses that typically precede clearance of hepatitis infection in patients that mount an immune response. The Company stated that the results provided the biological proof of concept necessary to proceed with the design and conduct of definitive efficacy studies of Theradigm-HBV.

Cytel has scheduled a conference call with the investment community to discuss these results and continued progress in the Theradigm-HBV trials for Thursday June 6, at 6:00 a.m. Pacific Time (9:00 a.m. Eastern Time). If you would like to participate in this call, please call 800-633-8523 (International callers, dial 212-346-0200) and ask for the "Cytel Press Release Conference Call." If you are unable to join this call, you will be able to access a recording of the proceedings from 12:00 p.m.-5:00 p.m. Eastern Time (9:00-2:00 p.m. Pacific Time) by dialing 800-633-8284 and using the reservation No. 1793436.

Actual results may differ materially from the above forward-looking statements due to a number of important factors, including but not limited to the timing and cost of conducting human clinical trials and the possibility that further testing may not support the results of the data described above or may reveal undesirable and unintended side effects or other characteristics that may prevent or limit its commercial use. These factors are more fully discussed in the Company's most recent Form 10-K and Form 10-Qs.

CONTACT: Karin Eastham

Vice President and Chief Financial Officer

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