EXHIBIT 99.1





            EUROPEAN PATENT OFFICE AFFIRMS REVOCATION OF DYAX PATENT

CAMBRIDGE, Mass., July 2, 2002 -- Dyax Corp. (Nasdaq: DYAX) today announced that
the Technical Board of Appeal of the European Patent Office (EPO) affirmed the
April 2000 revocation of Dyax's European patent on phage display, European
Patent 436,597 (the "'597 patent"), in proceedings brought by Cambridge Antibody
Technology and Acambis Research Limited. The EPO Technical Board of Appeal ruled
that the patent was not valid on the grounds that it failed to provide
verification of the claimed display of a proteinaceous binding domain. This
decision by the Board is final and cannot be appealed.

This decision only affects Dyax's '597 patent in Europe and does not impact
Dyax's other fundamental patents in the field of phage display technology in the
United States, Canada and Israel, as well as additional patent applications in
the U.S and Japan. Dyax also has divisional patent applications of the '597
patent now pending in the EPO and intends to vigorously prosecute these
applications, taking into consideration this decision.

"Based on our four issued U.S. patents and a Canadian patent, as well as our
Japanese and United States applications and our other proprietary technology, we
are confident that our intellectual property position in protein and peptide
display remains strong," said Henry E. Blair, Dyax's President and Chief
Executive Officer. "While we are disappointed with the EPO's decision, the
ruling will not affect our ability to move forward using our phage display
technology to discover therapeutic candidates, imaging agents, reagents, and
separations ligands for Dyax and our collaborators."


DYAX CORP.

Dyax Corp. is a biopharmaceutical company focused on the discovery, development
and commercialization of therapeutic products. The company uses its patented
phage display technology to identify a broad range of protein, peptide, and
antibody compounds with potential to treat a variety of inflammatory diseases
and cancers. Dyax has two protein product candidates, each for a different
inflammatory disease, in early stage clinical trials and is about to begin
clinical trials for one of these therapeutic candidates in another indication.
Dyax leverages its technology broadly through licenses and collaborations in
therapeutics and in non-core areas of affinity separations, diagnostics and
imaging, and research reagents. Through its subsidiary, Biotage, Inc., Dyax
develops, manufactures and sells chromatography separations systems and products
worldwide for drug discovery and purification.

DYAX DISCLAIMER

This press release contains forward-looking statements, including statements
regarding the potential uses and benefits of phage display in the identification
of therapeutic products and other products and our proprietary position in phage
display. Statements that are not historical facts are based on our current
expectations, beliefs, assumptions, estimates, forecasts and projections for
Dyax and the industry and markets in which Dyax competes. The statements
contained in this release are not guarantees of future performance and involve
certain risks, uncertainties and assumptions which are difficult to predict.
Therefore, actual outcomes and results may differ materially from what is
expressed in such forward-looking statements. Important factors which may affect
the uses and benefits of our phage display technology and our proprietary
position in phage display include our dependence on the expertise, effort,
priorities and contractual obligations of our licensees in the development,
clinical trials, manufacture, marketing, sales and distribution of
biopharmaceuticals developed by us or our licensees; our ability to obtain and
maintain intellectual property protection for our products and technologies; the
development of technologies or products superior to our technologies or
products; and other risk factors described or referred to in our most recent
Annual Report on Form 10-K and other periodic reports filed with the Securities
and Exchange Commission. Dyax cautions investors not to place undue reliance on
the forward-looking statements contained in this release. These statements speak
only as of the date of this release, and Dyax undertakes no obligation to update
or revise these statements, except as may be required by law.


CONTACT:
Dyax Corp.
Jack Morgan
617/250-5762
jmorgan@dyax.com