Exhibit 99.1
ALEXION Pharmaceuticals Acquires Prolifaron Establishing Premier Antibody
Discovery and Development Platform
Combinatorial Antibody Technologies Designed to Rapidly Develop Fully Human
Antibodies
New Haven, CT, September 25, 2000 -- Alexion Pharmaceuticals, Inc. (Nasdaq:
ALXN) today announced that it has acquired Prolifaron, Inc., a privately held
development stage biopharmaceutical company located in San Diego, CA, which
possesses extensive combinatorial human antibody library technologies and
expertise. Prolifaron has been renamed Alexion Antibody Technologies (AAT),
Inc., a wholly-owned subsidiary of Alexion.
Under the terms of the agreement, Alexion common stock with an aggregate value
of approximately $41 million, based upon a 10-day average price, has been
exchanged for all outstanding shares and options of Prolifaron. The acquisition
is expected to be accounted for using the purchase method of accounting. Alexion
Antibody Technologies, Inc. is expected to continue under the leadership of
Prolifaron's co-founder and President, Katherine S. Bowdish, Ph.D., who will
report to Stephen P. Squinto, Ph.D., Executive Vice President and Head of
Research at Alexion.
AAT's goal is to develop new fully human therapeutic antibodies addressing
multiple disease areas, including autoimmune and inflammatory disorders and
cancer. AAT's technologies involve the generation of combinatorial libraries of
human antibodies and the screening of these libraries against a wide array of
potential drug targets. Alexion believes that these technologies are optimally
suited to the rapid generation of novel fully human therapeutic antibodies
directed at validated clinical targets, already identified by Alexion. In
addition, these technologies could permit the simultaneous and efficient
identification of newly discovered genomic targets and their corresponding human
antibody therapeutics. Alexion believes that merging this broad enabling
discovery platform with its current established antibody development
capabilities, may allow the expedited development of a new wave of human
antibody therapeutics. Alexion expects that it will clinically develop and
market these new fully human antibody therapeutics provided by AAT. For more
details see Backgrounder. "Prolifaron's technologies and combinatorial antibody
libraries provide Alexion with an outstanding platform for the expansion of our
current antibody drug development program," stated Dr. Squinto of Alexion. "We
have been very impressed with the innovative, aggressive science already
established at Prolifaron under Dr. Bowdish's leadership. We expect that, within
Alexion, continued evolution of these technologies should provide additional
discovery opportunities and drug development candidates. We are particularly
excited to apply these combinatorial antibody technologies to rapidly generate
new drug candidates against a number of autoimmune, inflammatory, and cancer
targets already identified by Alexion, as well as to advance catalytic
antibodies as potential anticancer therapeutics."
-1-
<PAGE>
In addition to its broadly enabling combinatorial human antibody technologies,
Prolifaron has also pioneered the development of a series of catalytic
antibodies. Each of these antibodies is designed to simultaneously bind to a
particular cancer and convert an inactive form of an anti-cancer
chemotherapeutic pro-drug to its active drug form specifically at the surface of
the cancer. In addition to Dr. Bowdish, the three additional co-founders of
Prolifaron include world class antibody engineering scientists at The Scripps
Research Institute, La Jolla, CA - Dr. Richard Lerner, President of The Scripps
Research Institute, and Drs. Dennis Burton and Carlos Barbas. Drs. Lerner,
Burton, and Barbas have joined Alexion's Scientific Advisory Board at the
closing of the transaction.
"I am extremely pleased by the incorporation of Prolifaron's combinatorial human
antibody technologies within Alexion," commented Leonard Bell, MD, Alexion's
President and Chief Executive Officer. "As we advance our two lead antibody
product candidates in eight clinical indications including clinical efficacy
trials designed to enroll 3,000 - 4,000 patients, we are committed to further
expanding our antibody product portfolio. We expect to generate additional
antibody product candidates targeting significant inflammation, autoimmune
disease, and cancer indications, each addressing significant unmet patient
needs. By harnessing Prolifaron's broadly enabling combinatorial human antibody
technologies together with Alexion's established antibody development expertise,
our aim is to become the premier antibody discovery and development firm."
"We are very excited to join Alexion and to merge our antibody discovery
platform with such a highly regarded and experienced antibody development
program," stated Dr. Bowdish. "Additionally, the interaction of our current San
Diego-based discovery group with the larger Alexion research program and
experienced Alexion clinical groups should provide valuable focus and direction
to the discovery programs."
Alexion is engaged in the discovery and development of therapeutic products
aimed at treating patients with a wide array of severe disease states. Alexion's
two lead product candidates are currently in eight clinical development
programs. 5G1.1-SC, in collaboration with Procter & Gamble, is in a Phase IIb
cardiopulmonary bypass efficacy trial and in two Phase II myocardial infarction
efficacy trials. 5G1.1 is currently in a Phase II efficacy trial for the chronic
treatment of rheumatoid arthritis, a Phase II efficacy trial for the treatment
of membranous nephritis and in Phase Ib pilot studies for treatment of
psoriasis, dermatomyositis, and pemphigoid. This press release and further
information about Alexion Pharmaceuticals, Inc. can be found on the World Wide
Web at: www.AlexionPharm.com.
Backgrounder
Alexion Antibody Technology, Inc. (formerly Prolifaron, Inc), a wholly owned
subsidiary of Alexion Pharmaceuticals, Inc. is utilizing its Combinatorial Human
Monoclonal Antibody Library Technology (CoALT) to develop more specific human
antibody therapeutics. This
-2-
<PAGE>
proprietary technology allows for the rapid identification of high affinity
fully human antibodies to an almost unlimited range of human antigens. AAT will
initially focus its efforts in the areas of autoimmune and inflammatory
disorders and cancer.
What is an Antibody? An antibody is a protein normally produced by B cells in
response to an antigen (a substance foreign to the body). An antibody consists
of both highly variable protein sequences (V regions) responsible for specific
binding to the antigen and a constant protein sequence (C region) which can
contribute to the biological activity of the antibody.
What is a Fully Human Antibody? A fully human antibody has both V and C protein
regions encoded entirely by human gene sequences. As a consequence, fully human
antibodies are not expected to elicit an immune response in humans.
What is a Therapeutic Antibody? A therapeutic antibody is an antibody
administered to an individual in order to modify a disease. Therapeutic
antibodies to date have consisted of murine antibodies (mouse V and C
sequences), chimeric antibodies (mouse V regions with human C regions),
humanized antibodies (mostly human V regions with human C regions), and fully
human antibodies (human V and C regions).
What is a Monoclonal Antibody? Monoclonal antibodies are antigen specific
antibodies derived from a single B cell, as opposed to polyclonal antibodies
derived from many B cells. Monoclonal antibodies were originally produced by
immunizing animals with an antigen and then isolating the individual B cell
which produces a particular antibody against the selected antigen.
What is a hybridoma? Hybridomas are cells that are derived from the fusion of a
myeloma cell that can grow indefinitely with a normal antigen-specific
individual B cell. They can thus produce monoclonal antibodies in significant
quantities.
What is a Combinatorial Antibody Library? Rather than utilizing animals to
elicit an antibody response and the derivation of a monoclonal antibody, the
full repertoire of human antibody V region genes can be cloned from human B
cells and assembled into a molecular library. This molecular library can be
inserted into a vector that allows for the recombination of antibody V genes in
bacteria and the display of billions of human antibodies on the surface of the
bacteria.
What is Biopanning? Biopanning refers to the selection of a desired human
antibody from the combinatorial antibody library based on its ability to bind
tightly to a target human antigen.
What is a Pro-drug? A Prodrug is a chemically inert organic compound capable of
being converted to a potent chemical compound through the activity of an enzyme.
What is a Catalytic Antibody? A Catalytic Antibody is an antibody capable of
performing a specific enzymatic reaction upon binding to its target. AAT is
developing proprietary catalytic
-3-
<PAGE>
antibodies capable of enzymatically converting several chemotherapeutic prodrugs
into their active forms at the site of specific tumors.
This news release contains forward-looking statements. Such statements are
subject to certain factors which may cause Alexion's plans to differ or results
to vary from those expected including unexpected pre-clinical or clinical
results, the need for additional research and testing, delays in manufacturing,
access to capital and funding, delays and adverse changes in development of
commercial relationships and a variety of risks set forth from time to time in
Alexion's filings with the Securities and Exchange Commission, including but not
limited to the risks discussed in Alexion's Annual Report on Form 10-K/A for the
year ended July 31, 1999. Alexion undertakes no obligation to publicly release
results of any of these forward-looking statements which may be made to reflect
events or circumstances after the date hereof or to reflect the occurrence of
unanticipated events.
-4-
