AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 18, 1997
 
                                                     REGISTRATION NO. 333-19905
    
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                   ----------
   
                         POST-EFFECTIVE AMENDMENT NO. 1

                                       TO

                                    FORM S-1

                                       ON

                                    FORM S-3
    
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                                   ----------

                          ALEXION PHARMACEUTICALS, INC.
             (Exact name of registrant as specified in its charter)


         DELAWARE                          2834                    13-3648318
- ----------------------------     --------------------------     ----------------
(State or other jurisdiction         (Primary Standard          (I.R.S. Employer
    of incorporation or          Industrial  Classification      Identification 
       organization)                    Code Number)                 Number)


                                25 SCIENCE PARK
                               NEW HAVEN, CT 06511
                                   (203) 776-1790
       ------------------------------------------------------------------
       (Address, including zip code, and telephone number, including area
               code, of registrant's principal executive offices)

                                   ----------

                               LEONARD BELL, M.D.
                          ALEXION PHARMACEUTICALS, INC.
                                 25 SCIENCE PARK
                               NEW HAVEN, CT 06511
                                   (203) 776-1790
            ---------------------------------------------------------
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

                                   ----------

           Copies of all communications, including all communications
                sent to the agent for service, should be sent to:

                            MERRILL M. KRAINES, ESQ.
                           FULBRIGHT & JAWORSKI L.L.P.
                                666 FIFTH AVENUE
                            NEW YORK, NEW YORK 10103

                                   ----------
   
     APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: From time
to time after the effective date of this Registration Statement.

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, as amended, check the following box. [X]

      If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. [ ]

      If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [ ]

     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [ ]

                                   ----------

   THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.
    
================================================================================






                          ALEXION PHARMACEUTICALS, INC.

                                1,609,368 SHARES

                                  COMMON STOCK


     This Prospectus relates to the resale of shares of Common Stock, $.0001 par
value per share (the "Common Stock") of Alexion Pharmaceuticals, Inc. (the
"Company" or "Alexion") from time to time for the account of the Selling
Stockholders (the "Selling Stockholders"). Certain of the Common Stock
registered hereby is issuable upon the exercise of warrants (the "Warrants")
owned by the Selling Stockholders. The Company will not receive any of the
proceeds from the sale of the Common Stock by the Selling Stockholders. The
proceeds from the exercise of the Warrants, if any, will be received by the
Company. See "Use of Proceeds."

     The shares of Common Stock offered hereby were acquired by the Selling
Stockholders from the Company in the Company's private placements of securities
during 1992 and 1993 (the "Private Placements") or, as stated above, will be
acquired upon the exercise of the Warrants which were issued by the Company in
connection with the Private Placements. The Warrants consist of (i) warrants to
purchase shares of Common Stock at a price of $15.00 per share, subject to
adjustment in certain circumstances, exercisable at any time prior to the close
of business on December 4, 1997, which were issued to purchasers in the Private
Placements (the "Placement Warrants"), (ii) warrants to purchase shares of
Common Stock at a price of $12.50 per share, subject to adjustment in certain
circumstances, exercisable at any time prior to the close of business on
December 4, 1997, which were issued to the placement agent for the Private
Placements (the "Placement Agent Warrants"), and (iii) warrants to purchase
shares of Common Stock at a price of $7.50 per share, subject to adjustment in
certain circumstances, exercisable at any time prior to the close of business on
December 4, 1997, which were issued in exchange for certain of the Placement
Warrants and Placement Agent Warrants (the "Exchange Warrants"). See
"Description of Securities."

     The distribution of the Common Stock by the Selling Stockholders may be
effected from time to time in one or more transactions (which may involve block
transactions) in the over-the-counter market (including the Nasdaq National
Market) or any exchange on which the Common Stock may then be listed, in
negotiated transactions, through the writing of options on shares (whether such
options are listed on an options exchange or otherwise), or a combination of
such methods of sale, at market prices prevailing at the time of sale, at prices
related to such prevailing market prices or at negotiated prices. The Selling
Stockholders may effect such transactions by selling shares to or through
broker-dealers, and such broker-dealers may receive compensation in the form of
underwriting discounts, concessions or commissions from the Selling Stockholders
and/or purchasers of shares for whom they may act as agent (which compensation
may be in excess of customary commissions). The Selling Stockholders may also
sell the shares of Common Stock pursuant to Rule 144 promulgated under the
Securities Act of 1933, as amended (the "Securities Act"), or may pledge shares
as collateral for margin accounts and such shares could be resold pursuant to
the terms of such accounts. The Selling Stockholders and any broker-dealers that
act in connection with the sale of Common Stock might be deemed to be
"underwriters" within the meaning of Section 2(11) of the Securities Act and any
commissions received by them and any profit on the resale of the shares might be
deemed to be underwriting discounts or commissions under the Securities Act. The
Selling Stockholders may agree to indemnify any agent, dealer or broker-dealer
that participates in transactions involving sales of the Common Stock against
certain liabilities, including liabilities arising under the Securities Act.
   
     The Company's Common Stock trades on the Nasdaq National Market under the
symbol "ALXN." On July 17, 1997, the closing sale price of the Common Stock was
$10 1/4 per share.
    
   All expenses of the registration of securities covered by this Prospectus are
to be borne by the Company, except that the Selling Stockholders will pay
underwriting discounts, selling commissions, and fees and the expenses, if any,
of counsel or other advisers to the Selling Stockholders.

                                    ---------

          THE SECURITIES OFFERED HEREBY INVOLVE A HIGH DEGREE OF RISK.
   
                      SEE "RISK FACTORS" LOCATED ON PAGE 7.
    
                                    ---------

     THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE
SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED
UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE
CONTRARY IS A CRIMINAL OFFENSE.

                                    ---------

   
                 The date of this Prospectus is July 18, 1997
    




   
No person is authorized in connection with the offering made hereby to give any
information or to make any representation not contained or incorporated by
reference in this Prospectus, and any information or representation not
contained or incorporated herein must not be relied upon as having been
authorized by the Company or the Selling Stockholders. This Prospectus does not
constitute an offer to sell or a solicitation of an offer to buy by any person
in any jurisdiction in which it is unlawful for such person to make such offer
or solicitation. Neither the delivery of this Prospectus at any time nor any
sale made hereunder shall under any circumstance imply that the information
contained herein is correct as of any date subsequent to the date hereof.
    
                            AVAILABLE INFORMATION
   
     The Company is subject to the informational requirements of the Securities
Exchange Act of 1934, as amended (the "Exchange Act"), and, in accordance
therewith, files reports and other information with the Securities and Exchange
Commission (the "Commission"). Proxy statements, reports and other information
concerning the Company can be inspected and copied at the public reference
facilities maintained by the Commission at Room 1024, Judiciary Plaza, 450 Fifth
Street, N.W., Washington, D.C. 20549 and the regional offices of the Commission
located at Seven World Trade Center, 13th Floor, New York, New York 10048, and
500 West Madison Street, Chicago, Illinois 60661, and copies of such material
can be obtained from the Public Reference Section of the Commission at 450 Fifth
Street, N.W., Washington, D.C. 20549, and its public reference facilities in New
York, New York and Chicago, Illinois, at prescribed rates. Copies of such
information may also be inspected at the reading room of the library of the
National Association of Securities Dealers, Inc., 1735 K Street, Washington,
D.C. 20006. This Prospectus does not contain all of the information set forth in
the Registration Statement of which this Prospectus is a part and exhibits
thereto which the Company has filed with the Commission under the Securities Act
of 1933 as amended (the "Securities Act") and to which reference is hereby made.
The Commission maintains a World Wide Web site on the Internet at
http://www.sec.gov that contains reports, proxy and information statements and
other information regarding the Company and other registrants that file
electronically with the Commission.

     This Prospectus constitutes a part of a Registration Statement on Form S-3
(herein, together with all amendments and exhibits, referred to as the
"Registration Statement") filed by the Company with the Commission under the
Securities Act. This Prospectus does not contain all of the information set
forth in the Registration Statement, certain parts of which are omitted in
accordance with the rules and regulations of the Commission. For further
information with respect to the Company and the Common Stock, reference is
hereby made to the Registration Statement. Statements contained herein
concerning the provisions of any contract, agreement or other document are not
necessarily complete, and in each instance reference is made to the copy of such
contract, agreement or other document filed as an exhibit to the Registration
Statement or otherwise filed with the Commission. Each such statement is
qualified in its entirety by such reference. Copies of the Registration
Statement together with exhibits may be inspected at the offices of the
Commission as indicated above without charge and copies thereof may be obtained
therefrom upon payment of a prescribed fee.

         PRIVATE SECURITIES LITIGATION REFORM ACT SAFE HARBOR STATEMENT

     This Prospectus (including the documents incorporated by reference herein)
contains certain forward-looking statements (as such term is defined in the
Private Securities Litigation Reform Act of 1995) and information relating to
Alexion that are based on the beliefs of the management of Alexion, as well as
assumptions made by and information currently available to the management of
Alexion. When used in this Prospectus, the words "estimate," "project,"
"believe," "anticipate," "intend," "expect" and similar expressions are intended
to identify forward-looking statements. Such statements reflect the current
views of Alexion with respect to future events and are subject to risks and
uncertainties that could cause actual results to differ materially from those
contemplated in such forward-looking statements. For a discussion of such risks,
see "Risk Factors." Readers are cautioned not to place undue reliance on these
forward-looking statements, which speak only as of the date hereof. Alexion does
not undertake any obligation to publicly release any revisions to these forward
looking statements to reflect events or circumstances after the date hereof or
to reflect the occurrence of unanticipated events.
    

                                      -2-





   
               INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

     The following documents filed by Alexion Pharmaceuticals, Inc. are
incorporated herein by reference and made a part hereof:

          1. The Company's Annual Report on Form 10-K for the fiscal year ended
     July 31, 1996.

          2. The Company's Quarterly Report on Form 10-Q for the fiscal quarter
     ended October 31, 1996.

          3. The Company's Quarterly Report on Form 10-Q for the fiscal quarter
     ended January 31, 1997, as amended by Form 10-Q/A, filed March 17, 1997,
     and Form 10Q/A2, filed June 19, 1997.

          4. The Company's Quarterly Report on Form 10-Q for the fiscal quarter
     ended April 30, 1997.

          5. The description of the Company's Common Stock contained in Item 1
     of the Company's Registration Statement on Form 8-A, dated February 12,
     1996.

          6. The Company's Current Report on Form 8-K, dated February 28, 1997.

          7. The Company's Current Report on Form 8-K, filed June 18, 1997.

          8. The Company's Current Report on Form 8-K, filed July 11, 1997.

     In addition to the foregoing, all documents subsequently filed by the
Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities
Exchange Act of 1934, prior to the filing of a post-effective amendment
indicating that all of the securities offered hereunder have been sold or
deregistering all securities then remaining unsold, shall be deemed to be
incorporated by reference in this Registration Statement and to be part hereof
from the date of filing of such documents. Any statement contained in a document
incorporated by reference in this Registration Statement shall be deemed to be
modified or superseded for purposes of this Registration Statement to the extent
that a statement contained herein or in any subsequently filed document that is
also incorporated by reference herein modifies or supersedes such statement. Any
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of this Registration Statement.

     This Prospectus incorporates documents by reference which are not presented
herein or delivered herewith. These documents are available upon request from:
Alexion Pharmaceuticals, Inc., 25 Science Park, New Haven, CT 06511, Attention:
David W. Keiser, Executive Vice President and Chief Operating Officer, (203)
776-1790. The Company undertakes to provide without charge to each person to
whom this Prospectus is delivered, upon written or oral request of such person,
a copy of any or all of the foregoing documents incorporated by reference
herein, other than exhibits to such documents, unless such exhibits are
specifically incorporated by reference into such documents.

    

                                      -3-





                               PROSPECTUS SUMMARY
   
     The following summary is qualified in its entirety by the more detailed
information and financial data appearing elsewhere or incorporated by reference
in this Prospectus. Investors should carefully consider the information set
forth under the heading "Risk Factors."

     This Prospectus contains forward-looking statements which involve risks and
uncertainties. The Company's actual results could differ materially from those
anticipated in these forward-looking statements as a result of certain factors,
including those set forth under "Risk Factors" and elsewhere in, or incorporated
by reference in this Prospectus.

                                   THE COMPANY

     Alexion Pharmaceuticals, Inc. ("Alexion" or the "Company") is a
biopharmaceutical company engaged in research and the development of proprietary
immunoregulatory compounds for the treatment of autoimmune and cardiovascular
diseases. The Company is developing C5 complement inhibitors ("C5 Inhibitors")
and Apogens ("Apogens"), two classes of potential therapeutic compounds designed
to selectively target specific disease-causing segments of the immune system.
The Company believes that its C5 Inhibitors and Apogens, which are based upon
distinct immunoregulatory technologies, may have the advantage of achieving a
higher level of efficacy with the potential for reduced side effects when
compared to existing therapeutic approaches. Alexion's lead C5 Inhibitor,
5G1.1-SC, is currently being studied in a Phase I/II clinical trial in
cardiopulmonary bypass patients. The Company's lead Apogen product candidate,
MP4, for the treatment of multiple sclerosis is expected to enter clinical
trials in the second half of 1997. The Company will need to undertake and
complete further tests in order to confirm its belief regarding the safety and
efficacy of its product candidates, and there can be no assurance as to the
results of any such tests.

     As an outgrowth of its core immunoregulatory technologies, the Company is
developing immunoprotected materials for transplantation and gene therapy. In
collaboration with United States Surgical Corporation ("US Surgical"), Alexion
is developing non-human UniGraft organ products which are designed for
transplantation into humans. Further, in a collaboration with Genetic Therapy
Inc., a subsidiary of Novartis ("GTI/Novartis"), which was initiated in December
1996, Alexion is developing immunoprotected gene transfer systems which are
designed to enable the injectable delivery of therapeutic genes to patients'
cells. See "Recent Developments" below.
    
     The Human Immune System. The role of the human immune system is to defend
the body from attack or invasion by infectious agents or pathogens. This is
accomplished through a complex system of proteins and cells, primarily
complement proteins, antibodies and various types of white blood cells, each
with a specialized function. Under normal circumstances, complement proteins,
together with antibodies and white blood cells, act beneficially to protect the
body by removing pathogenic microorganisms, cells containing antigens (foreign
proteins), and disease-causing immune complexes (combinations of antigens and
antibodies). However, any number of stimuli, including antibodies, pathogenic
microorganisms, injured tissue, normal tissue, proteases (inflammatory enzymes)
and artificial surfaces can locally activate complement proteins in a cascade of
enzymatic and biochemical reactions (the "complement cascade") to form
inflammatory byproducts leading, for example, in the case of rheumatoid
arthritis, to severe joint inflammation and, in the case of cardiovascular
disorders such as myocardial infarction (death of heart tissue), to additional
significant damage to the heart tissue. T-cells, a type of white blood cell,
play a critical role in the normal immune response by recognizing cells
containing antigens, initiating the immune response, attacking the
antigen-containing tissue and directing the production of antibodies directed at
the antigens, all of which lead to the elimination of the antigen-bearing
foreign organism. When a T-cell mistakenly attacks host tissue, the T-cell may
cause an inflammatory response resulting in tissue destruction and severe
autoimmune disease leading, for example, in the case of multiple sclerosis, to
severe and crippling destruction of nerve fibers in the brain.


                                      -4-





   
     C5 Inhibitors. Alexion is developing specific and potent biopharmaceutical
C5 Inhibitors which are designed to intervene in the complement cascade at what
the Company believes to be the optimal point so that the disease-causing actions
of complement proteins generally are inhibited while the normal
disease-preventing functions of complement proteins generally remain intact. In
laboratory and animal models of human disease, Alexion has shown that C5
Inhibitors are effective in substantially preventing inflammation during
cardiopulmonary bypass ("CPB"), limiting myocardial infarction during coronary
ischemia and reperfusion, enhancing survival in lupus and preserving kidney
function in nephritis (kidney inflammation) and reducing the incidence and
severity of inflammation and joint damage in rheumatoid arthritis. The Company
is developing two C5 Inhibitors, a short acting humanized (compatible for human
use) single chain antibody (5G1.1-SC) designed for acute therapeutic settings
such as in CPB procedures and in treating myocardial infarctions, and a long
acting humanized monoclonal antibody (5G1.1) designed for treating chronic
disorders such as nephritis and rheumatoid arthritis. See "Recent Developments"
below for a discussion of the regulatory status of 5G1.1-SC. The Company's long
acting monoclonal antibody is in process development.

     Apogens. The Company's Apogen compounds are based upon discoveries at the
National Institutes of Health ("NIH") which are exclusively licensed to Alexion
and upon further discoveries by Alexion. These discoveries involve a mechanism
by which substantially all disease-causing T-cells are selectively eliminated in
vivo in animal models of disease. The highly specific recombinant Apogens under
development by the Company are designed to selectively eliminate disease-causing
T-cells in patients with certain autoimmune diseases including multiple
sclerosis and diabetes mellitus. The Company has demonstrated that its lead
proprietary Apogen, MP4 ("MP4"), is effective at preventing neurologic disease
and in ameliorating established disease in animal models of multiple sclerosis.
Clinical trial quantities of MP4 are currently in production and the Company
anticipates it will file an IND for the multiple sclerosis indication in the
second half of 1997.

     UniGraft Program. The Company's UniGraft program, in collaboration with US
Surgical, is focused on developing non-human organ products designed for
transplantation into humans without clinical rejection. Alexion has tested
genetically engineered pig hearts, livers and lungs in primates and has
demonstrated transplant organ function substantially longer than for
transplanted non-genetically engineered porcine organs.

     Gene Transfer Systems. Alexion is developing, in collaboration with
GTI/Novartis, immunoprotected retroviral vector particles and producer cells
which are designed to resist rejection and therefore may be able to be used for
direct injectable delivery of therapeutic genes to patients' cells. Such
particles and producer cells are being engineered by Alexion for subsequent
preclinical evaluation by GTI.
    
     The Company was founded in New Haven, Connecticut in January 1992 with
scientific founders largely drawn from the faculty of Yale University. The
Company's principal executive offices are at 25 Science Park, New Haven,
Connecticut 06511, and its telephone number is (203) 776-1790.



                                      -5-




   

                             RECENT DEVELOPMENTS


C5 Inhibitor 5G1.1-SC Clinical Trials
- -------------------------------------

     An Investigational New Drug application ("IND") was filed with the United
States Food and Drug Administration ("FDA") during March 1996 for 5G1.1-SC, and
after receiving FDA authorization, a Phase I clinical trial in healthy male
volunteers began in June 1996. Results of the Phase I trial indicated that a
single dose administration of 5G1.1-SC was safe and well-tolerated in the study
population. In September 1996, the Company received FDA authorization for its
second clinical trial and in October 1996 commenced a Phase I/II study of
5G1.1-SC in patients undergoing CPB.


Gene Transfer Systems - GTI/Novartis
- ------------------------------------

     In December 1996, Alexion and GTI/Novartis entered into a License and
Collaborative Research Agreement with respect to the Company's gene transfer
technology. Under the Agreement, GTI/Novartis has been granted a worldwide
exclusive license to use the Alexion technology in its gene therapy products.
Terms of the agreement call for Alexion to receive up front license fees,
research payments and milestone payments from GTI/Novartis totalling up to $10
million. Alexion will also receive royalties on net sales of such products, if
any.


ApogenMS - MP4
- --------------

     In April 1997, Alexion announced the results of a study demonstrating the
efficacy of MP4, Alexion's proprietary Apogen compound, for the treatment of
Multiple Sclerosis ("MS") in a primate model of MS. In the study, relative to
untreated control animals, treatment with MP4 was associated with a clear
dose-dependent reduction in the severity of symptoms, with animals in the high
dose treatment group displaying no apparent clinical manifestations of disease.
Further, MP4 prolonged the time to onset of lesions detected by magnetic
resonance imaging. There can be no assurance that the results of studies in
animals can be reproduced, or are predictive of results, in humans. See "Risk
Factors - Early Stage of Product Development; Risks of Clinical Trials."


Private Placement of Common Stock
- ---------------------------------

     Pursuant to Stock Purchase Agreements, dated as of June 12, 1997 (the
"Stock Purchase Agreements"), with certain "accredited investors," the investors
purchased 1,450,000 shares of the Common Stock of the Company at a price of
$7.75 per share. The sale of the shares was made subject to the effectiveness of
a resale registration statement and, on July 8, 1997, a registration statement
relating to the resale of the shares was declared effective by the Securities
and Exchange Commission. The offer and sale by the Company of the Common Stock
to the investors pursuant to the Stock Purchase Agreements was made pursuant to
an exemption from the registration requirements of the Securities Act provided
by Section 4(2) thereof. Robertson, Stephens & Company LLC ("RS & Co.") acted as
the placement agent for the private placement. The Company paid RS & Co.
commissions of 6% of the gross proceeds, or $674,250 in the aggregate, in
addition to expenses. RS & Co. paid 10% of its fees to Josephthal Lyon & Ross
Incorporated for its assistance in connection with the private placement.
    

                                      -6-






                                 RISK FACTORS

     An investment in the Common Stock offered hereby involves a high degree of
risk. Prospective investors should consider carefully the following risk
factors, as well as the other information set forth in this Prospectus, in
connection with an investment in the Common Stock offered hereby. This
Prospectus contains forward-looking statements that involve risks and
uncertainties. The Company's actual results could differ materially from the
results discussed in the forward-looking statements. Factors that could cause or
contribute to such differences include, but are not limited to, those discussed
in "Risk Factors," as well as those discussed elsewhere in this Prospectus.
   
     Operating Losses; Uncertainty of Future Profitability. Alexion has
generated no revenues from product sales and is dependent upon its research and
development contracts, including the agreements with US Surgical and
GTI/Novartis, external financing, other research and development contracts and
research and development grants to the extent that they can be obtained and
interest income to pursue its intended business activities. The Company has
incurred losses since inception and has cumulative net losses of $29.1 million
through April 30, 1997. Losses have resulted principally from costs incurred in
research activities aimed at identifying and developing the Company's product
candidates and from general and administrative costs. The Company expects to
incur substantial additional operating losses over the next several years and
expects losses to increase as the Company's research and development efforts
expand and clinical trials continue and potentially expand. The Company's
ability to achieve profitability is dependent on its ability to obtain patent
protection and regulatory approval for its products, to obtain licenses from
third parties to use technology which it may need, to enter into agreements for
product development and commercialization with corporate partners and to develop
the capacity to manufacture and sell products. There can be no assurance that
the Company will successfully develop, commercialize, manufacture or market any
of its potential products, obtain required regulatory approvals, patents or
third party licenses to technology or ever achieve profitability.

     Early Stage of Product Development; Risks of Clinical Trials. The Company's
research and development programs are at an early stage. There can be no
assurance that the Company's drug discovery efforts will result in the
development of commercially successful therapeutic drugs. Potential products
which have been identified will require significant additional development,
preclinical and clinical testing, regulatory approval, and additional investment
prior to their commercialization, which may never be achieved. Potential
products may be found to be ineffective or cause harmful side effects during
preclinical testing or clinical trials, fail to receive necessary regulatory
approvals, be difficult to manufacture on a large scale, fail to achieve market
acceptance, be uneconomical or be precluded from commercialization by
proprietary rights of third parties. The results from preclinical studies and
early clinical trials may not be predictive of results that will be obtained in
large-scale clinical trials and do not necessarily predict or prove safety or
efficacy in humans.

     In addition, the Company has recently commenced clinical trials of one of
its product candidates. There can be no assurance that clinical trials of the
Company's product candidates will demonstrate sufficient safety and efficacy to
obtain the requisite regulatory approvals or will result in marketable products.
Clinical trials are often conducted with patients that are critically ill.
During the course of treatment, these patients can die or suffer other adverse
medical effects for reasons that may not be related to the pharmaceutical agent
being tested but which can nevertheless affect clinical trial results. A number
of companies in the pharmaceutical industry have suffered significant setbacks
in advanced clinical trials, even after promising results in earlier trials. Any
such setback could have a material adverse effect on the Company's business,
financial condition and results of operations. The completion of clinical trials
of the Company's product candidates may be delayed by many factors and there can
be no assurance that delays or terminations will not occur. One such factor is
the rate of enrollment of patients, which generally varies throughout the course
of a clinical trial and which depends on the size of the patient population, the
number of clinical trial sites, the proximity of patients to clinical trial
sites, the eligibility criteria for the trial and the existence of competing
clinical trials. The Company cannot control the rate at which patients present
themselves for enrollment, and there can be no assurance that the rate of
patient enrollment will be consistent with the Company's expectations or be
sufficient to enable clinical trials of the Company's product candidates to be
completed in a timely manner.
    

                                      -7-





   
     Need for Additional Funds. The Company will require substantial additional
funds for its research and product development programs, for operating expenses,
for pursuing regulatory approval and for developing required production, sales
and marketing capabilities. With the exception of the Company's agreements with
US Surgical and GTI/Novartis and certain research grants, the Company does not
have any commitments or arrangements to obtain any such funds and there can be
no assurance that funds for these purposes, whether through additional sales of
securities or collaborative or other arrangements with corporate partners or
from other sources, will be available to the Company when needed or on terms
favorable to the Company. The unavailability of additional financing could
require the Company to delay, scale back or eliminate certain of its research
and product development programs or to license third parties to commercialize
products or technologies that the Company would otherwise undertake itself, any
of which would have a material adverse effect on the Company. The Company
believes that its existing available resources, together with anticipated future
funding from US Surgical and GTI/Novartis and certain research grants, and
interest income should be sufficient to fund its operating expenses and capital
requirements as currently planned for at least 12 months. However, the Company's
cash requirements may vary materially from those now planned because of results
of research and development, results of product testing, relationships with
strategic partners, changes in the focus and direction of the Company's research
and development programs, competitive and technological factors, developments in
the regulatory process and other factors, none of which can be predicted.

     Rapid Technological Change. The Company is engaged in pharmaceutical fields
characterized by extensive research efforts, rapidly evolving technology and
intense competition from numerous organizations, including pharmaceutical
companies, biotechnology firms, academic institutions and others. New
developments are expected to continue at a rapid pace in both industry and
academia. There can be no assurance that research and discoveries by others will
not render any of the Company's programs or potential products obsolete or
uneconomical. In order to compete successfully, the Company will need to
complete development of and obtain regulatory approval of products that keep
pace with technological developments on a timely basis. Any failure by the
Company to anticipate or respond adequately to technological developments will
have a material adverse effect on the Company's business, financial condition
and results of operations.

     Patent, License and Proprietary Rights Uncertainties. The Company's success
will depend in part on its ability to obtain United States and foreign patent
protection for its products, preserve its trade secrets and proprietary rights,
and operate without infringing on the proprietary rights of third parties or
having third parties circumvent the Company's rights. Because of the length of
time and expense associated with bringing new products through development and
regulatory approval to the marketplace, the health care industry has
traditionally placed considerable importance on obtaining patent and trade
secret protection for significant new technologies, products and processes.
There can be no assurance that any patents will issue from any of the patent
applications owned by or licensed to the Company. Further, even if patents were
to issue, there can be no assurance that they will provide the Company with
significant protection against competitive products or otherwise be commercially
valuable. In addition, patent law relating to certain of the Company's fields of
interest, particularly as to the scope of claims in issued patents, is still
developing and it is unclear how this uncertainty will affect the Company's
patent rights. Litigation, which could be costly and time consuming, may be
necessary to enforce patents issued to the Company and/or to determine the scope
and validity of others' proprietary rights, in either case in judicial or
administrative proceedings. The Company's competitive position is also dependent
upon unpatented trade secrets which generally are difficult to protect. There
can be no assurance that others will not independently develop substantially
equivalent proprietary information and techniques or otherwise gain access to
the Company's trade secrets, that the Company's trade secrets will not be
disclosed or that the Company can effectively protect its rights to unpatented
trade secrets. As the biotechnology industry expands and more patents are
issued, the risk increases that the Company's potential products may give rise
to claims that they infringe the patents of others. Any such infringement
litigation would be costly and time consuming to the Company.

     The Company is aware of broad patents owned by third parties relating to
the manufacture, use, and sale of recombinant humanized antibodies, recombinant
humanized single chain antibodies and genetically engineered animals. The
Company has received notice from one company regarding the existence of a patent
which the owners claim may be relevant to the development and commercialization
of certain of the Company's proposed UniGraft organ transplantation products.
The Company has
    

                                      -8-


   
identified and is testing various approaches which it believes should not
infringe this patent and which should permit commercialization of its products.
There can be no assurance that the owner of this patent will not seek to enforce
the patent against the Company's so-modified commercial products or against the
development activities related to the non-modified products. To the extent it
becomes necessary, there can be no assurance that the Company will be able to
obtain a license on commercially reasonable terms. If the Company does not
obtain necessary licenses, it could encounter delays in product market
introductions while it attempts to design around such patent, or could find that
the development, manufacture or sale of products requiring such a license could
be foreclosed. Further, there can be no assurance that owners of patents that
the Company does not believe are relevant to the Company's product development
and commercialization will not seek to enforce their patents against the
Company. Such action could result in litigation which would be costly and time
consuming. There can be no assurance that the Company would be successful in
such litigations. The Company is currently unaware of any such threatened
action.

     Certain of the licenses by which the Company obtained its rights in and to
certain technologies require the Company to diligently commercialize or attempt
to commercialize such technologies. There can be no assurance that the Company
will meet such requirements, and failure to do so for a particular technology
could result in the Company losing its rights to that technology.

     Currently, the Company has not sought to register its potential trademarks
and there can be no assurance that the Company will be able to obtain
registration for such trademarks.

     No Assurance of FDA Approval; Government Regulation. The preclinical and
clinical testing, manufacturing, and marketing of the Company's products are
subject to extensive regulation by numerous government authorities in the United
States and other countries, including, but not limited to, the FDA. Among other
requirements, FDA approval of the Company's products, including a review of the
manufacturing processes and facilities used to produce such products, will be
required before such products may be marketed in the United States. Similarly,
marketing approval by a foreign governmental authority is typically required
before such products may be marketed in a particular foreign country. In order
to obtain FDA approval of a product, the Company must, among other things,
demonstrate to the satisfaction of the FDA that the product is safe and
effective for its intended uses and that the Company is capable of manufacturing
the product with procedures that conform to the FDA's then current good
manufacturing practice ("cGMP") regulations, which must be followed at all
times. The process of seeking FDA approvals can be costly, time consuming, and
subject to unanticipated and significant delays. There can be no assurance that
such approvals will be granted to the Company on a timely basis, or at all. Any
delay in obtaining or any failure to obtain such approvals would adversely
affect the Company's ability to introduce and market products and to generate
product revenue.

     The Company's research and development processes involve the controlled use
of hazardous materials. The Company is subject to federal, state and local laws
and regulations governing the use, manufacture, storage, handling and disposing
of such materials and certain waste products. In the event of such an accident,
the Company could be held liable for any damages that result and any such
liability could exceed the resources of the Company. There can be no assurance
that the Company will not be required to incur significant costs to comply with
the environmental laws and regulations in the future, or that the business,
financial condition and results of operations of the Company will not be
materially adversely affected by current or future environmental laws or
regulations.

     Substantial Competition. The pharmaceutical and biotechnology industries
are characterized by intense competition. Many companies, including major
pharmaceutical and chemical companies, as well as specialized biotechnology
companies, are engaged in activities similar to those of the Company. Certain of
these companies have substantially greater financial and other resources, larger
research and development staffs, and more extensive marketing and manufacturing
organizations than the Company. Many of these companies have significant
experience in preclinical testing, human clinical trials, product manufacturing,
marketing and distribution and other regulatory approval procedures. In
addition, colleges, universities, governmental agencies and other public and
private research organizations conduct research and may market commercial
products on their own or through joint ventures. These institutions are becoming
more active in seeking patent protection and licensing arrangements to collect
royalties for 
    

                                      -9-






use of technology that they have developed. These institutions also compete with
the Company in recruiting and retaining highly qualified scientific personnel.
   
     In particular, T-Cell Sciences, Inc. and Chiron Corporation have both
publicly announced intentions to develop complement inhibitors to treat diseases
related to trauma and inflammation indications and the Company is aware that
SmithKline Beecham Plc, Merck & Co., Inc. and CytoMed Inc. are attempting to
develop similar therapies. In addition, each of Bayer A.G. ("Bayer"), Immunex
Corporation, Pharmacia & Upjohn and Rhone-Poulenc Rorer, Inc. sells a product
which is used to reduce surgical bleeding during CPB. The Company is also aware
of announced and ongoing clinical trials of certain companies, including
Autoimmune, Inc., ImmuLogic Pharmaceutical Corporation, Neurocrine Biosciences,
Inc., and Anergen, Inc. employing T-cell specific tolerance technologies and
addressing patients with multiple sclerosis or diabetes mellitus. Baxter
Healthcare Corporation and Sandoz, Inc., in collaboration with Biotransplant
Inc., have publicly announced intentions to commercially develop xenograft
organs and the Company is aware that Diacrin Inc. is also working in this field.
These companies may succeed in developing products that are more effective or
less costly than any that may be developed by Alexion and may also prove to be
more successful than Alexion in production and marketing. Competition may
increase further as a result of potential advances in the commercial
applicability of biotechnology and greater availability of capital for
investment in these fields.

     Dependence on Qualified Personnel. The Company is highly dependent upon the
efforts of its senior management and scientific personnel including its
consultants, generally, and Dr. Leonard Bell, its President and Chief Executive
Officer, in particular. The Company and Dr. Bell are parties to an employment
agreement which expires on April 1, 2000. The loss of the services of one or
more of these individuals could have a material adverse effect on the Company's
ability to achieve its development objectives on a timely basis or at all. The
Company has a $2,000,000 key man life insurance policy on the life of Dr. Bell
of which the Company is the beneficiary. Because of the specialized scientific
nature of its business, Alexion is also highly dependent upon its ability to
continue to attract and retain qualified scientific and technical personnel.
There is intense competition for qualified personnel in the areas of the
Company's activities, and there can be no assurance that Alexion will be able to
continue to attract and retain the qualified personnel necessary for the
development of its business. Loss of the services of, or failure to recruit, key
scientific and technical personnel would be significantly detrimental to the
Company's product development programs.
    
     All members of the Company's Board of Scientific Advisors and the Company's
other scientific consultants are employed on a full-time basis by academic or
research institutions. Accordingly, such advisors and consultants will be able
to devote only a small portion of their time to the Company. In addition, in
certain circumstances, inventions or processes discovered by them may not become
the property of the Company but may be the property of their full-time employers
or of other companies and institutions for which they now consult. There can be
no assurance that the interests and motivations of the Company's collaborators
are or will remain consistent with those of the Company. Furthermore, there can
be no assurance that the Company will be able to successfully negotiate license
rights to the results of collaborations or that such licenses will be on
commercially reasonable terms.
   
     Dependence on Outside Parties and Collaborators. The Company's strategy for
the research, development, manufacture and commercialization of certain of its
products contemplates that it will enter into various arrangements with
corporate partners, licensors, licensees, outside researchers, consultants and
others and, therefore, the success of the Company is, and will be, dependent in
part upon the efforts of outside parties. There can be no assurance that the
Company will be able to negotiate acceptable collaborative arrangements to
develop or commercialize its products, that arrangements or other collaborations
entered into, if any, will be successful, or that current or potential
collaborators will not pursue treatments for other diseases or seek alternative
means of developing treatments for the diseases targeted by programs with the
Company. The Company has entered into research and development agreements with
US Surgical and GTI/Novartis to commercialize potential products to be developed
in the UniGraft program and for gene therapy. The amount and timing of resources
which US Surgical, GTI/Novartis or any other potential parties to collaboration
arrangements devote to these activities may not be within the control of the
Company. There can be no assurance that outside parties and collaborators will
perform their obligations as expected or that any revenue will be derived from
outside arrangements. The Joint Development Agreement with US Surgical may be
terminated by US Surgical 
    

                                      -10-





   
for any or no reason effective on or after January 1, 1998, if notice is given
by US Surgical at least six months prior thereto. If any of the Company's
collaborators breaches or terminates its agreement with the Company or otherwise
fails to conduct its collaborative activities in a timely manner, the
development or commercialization of the product candidate or the research
program which is the subject of the agreement may be delayed and the Company may
be required to undertake unforeseen additional responsibilities or to devote
additional resources to development or commercialization or terminate the
development or commercialization. This could have a material adverse effect on
the Company's prospects, financial condition, intellectual property position and
results of operations.

     Limited Manufacturing, Marketing, Sales, Clinical Testing and Regulatory
Compliance Capability. The Company has not invested in the development of
commercial manufacturing, marketing, distribution or sales capabilities.
Moreover, the Company has insufficient capacity to manufacture more than one
product candidate at a time or to manufacture its product candidates for later
stage clinical development or commercialization. If the Company is unable to
develop or contract for additional manufacturing capabilities on acceptable
terms, the Company's ability to conduct human clinical testing will be
materially adversely affected, resulting in delays in the submission of products
for regulatory approval and in the initiation of new development programs, which
could have a material adverse effect on the Company's competitive position and
the Company's prospects for achieving profitability. In addition, as the
Company's product development efforts progress, the Company will need to hire
additional personnel skilled in clinical testing, regulatory compliance, and, if
the Company develops products with commercial potential, marketing and sales.
There can be no assurance that the Company will be able to acquire, or establish
third-party relationships to provide, any or all of these resources or be able
to obtain required personnel and resources to manufacture, or perform testing or
engage in marketing, distribution and sales on its own.

     Uncertainty of Availability of Health Care Reimbursement. The Company's
ability to commercialize its products successfully may depend in part on the
extent to which reimbursement for the cost of such products and related
treatments will be available from government health administration authorities,
private health insurers and other organizations. Third-party payors are
attempting to control costs by limiting coverage of products and treatments and
the level of reimbursement for medical products and services. Significant
uncertainty exists as to the reimbursement status of newly approved health care
products, and if the Company succeeds in bringing one or more products to
market, there can be no assurance that these products will be considered
cost-effective, that reimbursement will be available, or, if available, that the
payor's reimbursement policies will not materially adversely affect the
Company's ability to sell its products on a profitable basis.

     Product Liability; Potential Liability for Human Clinical Trials. The
Company's business exposes it to potential product liability risks which are
inherent in the testing, manufacturing, marketing and sale of human therapeutic
products and there can be no assurance that the Company will be able to avoid
significant product liability exposure. With respect to the Company's UniGraft
program, little is known about the potential long-term health risks of
transplanting non-human tissue into humans. In addition to product liability
risks associated with sales of products, the Company may be liable to the claims
of individuals who participate in human clinical trials of its products. While
the Company has obtained, and will seek, waivers of liability from all persons
who participated or may in the future participate in human clinical trials
conducted by or on behalf of the Company, there can be no assurance that waivers
will be effective to protect the Company from liability or the costs of product
liability litigation. The Company currently has product liability insurance to
cover certain liabilities relating to the conduct of human clinical trials.
However, there can be no assurance that it will be able to maintain such
insurance on acceptable terms or that the insurance will provide adequate
protection against potential liabilities. An inability to maintain sufficient
insurance coverage at an acceptable cost or otherwise to protect against
potential product liability claims could prevent or limit the commercialization
of products developed by the Company. Furthermore, a product liability related
claim or recall could have a material adverse effect on the business, financial
condition and results of operations of the Company.

     Volatility of Share Price. The market prices for securities of
biopharmaceutical companies have been volatile. Factors such as announcements of
technological innovations or new commercial products by the Company or its
competitors, government regulation, patent or proprietary rights developments,
public concern as to the safety or other implications of biopharmaceutical
products, results of preclinical 
    

                                      -11-





   
or clinical trials, positive or negative developments related to the Company's
collaborators and market conditions in general may have a significant impact on
the market price of the Company's Common Stock.

     Dilutive Effect of Stock Issuances, Grants, Options and Warrants. As of
April 30, 1997, Alexion has granted options to purchase an aggregate of
approximately 1,332,334 shares of the Company's Common Stock under certain stock
option plans. Warrants to purchase an aggregate of approximately 945,669 shares
of the Company's Common Stock, including the Warrants, are also outstanding
under previous financing arrangements and other transactions. Many of these
options and warrants have exercise prices below the current market price of the
Company's Common Stock. In addition, the Company may issue additional stock,
warrants and/or options to raise capital in the future. The Company regularly
examines opportunities to expand its technology base through means such as
licenses, joint ventures and acquisition of assets or ongoing businesses and may
issue securities in connection with such transactions. The Company may also
issue additional securities in connection with its stock option plans. During
the terms of such options and warrants, the holders thereof are given the
opportunity to profit from a rise in the market price of the Company's Common
Stock. The exercise of such options and warrants may have an adverse effect on
the market value of the Company's Common Stock. The existence of such options
and warrants may adversely affect the terms on which the Company can obtain
additional equity financing. To the extent the exercise prices of such options
and warrants are less than the net tangible book value of the Company's Common
Stock at the time such options and warrants are exercised, the Company's
stockholders will experience an immediate dilution in the net tangible book
value of their investment.

     No Dividends. The Company has not paid dividends on any of its capital
stock since its inception and does not expect to pay cash or stock dividends on
its Common Stock in the foreseeable future.

     Possible Adverse Impact on Holders of Common Stock; Anti-takeover
Provisions; Rights Plan. The Board of Directors may issue one or more series of
Preferred Stock, without any action on the part of the stockholders of the
Company, the terms of which may adversely affect the rights of holders of Common
Stock. Issuance of Preferred Stock, which may be accomplished through a public
offering or a private placement, may dilute the voting power of holders of
Common Stock (such as by issuing Preferred Stock with super voting rights) and
may render more difficult the removal of current management, even if such
removal may be in the stockholders' best interests. Further, the issuance of
Preferred Stock may be used as an "anti-takeover" device without further action
on the part of the stockholders. On February 14, 1997, the Board of Directors of
Alexion declared a dividend distribution of one preferred stock purchase right
(a "Right") for each outstanding share of Common Stock of the Company. The
Rights are not exercisable until the date of the earlier to occur of (i) ten
business days following the time of a public announcement or notice to the
Company that a person or group of affiliated or associated persons has acquired
beneficial ownership of 20% or more of the outstanding shares of Common Stock of
the Company (such 20% beneficial owner, an "Acquiring Person"), or (ii) ten
business days, or such later date as may be determined by the Board of Directors
of the Company, after the date of the commencement or announcement by a person
of an intention to make a tender offer or exchange offer for an amount of Common
Stock which, together with the shares of such stock already owned by such
person, constitutes 20% or more of the outstanding shares of such Common Stock.
The Rights and the Rights Agreement, as well as certain provisions of Delaware
law are designed to prevent any unsolicited acquisitions of the Company's Common
Stock. These provisions and any issuance of Preferred Stock could prevent the
holders of Common Stock from realizing a premium on their shares.

     Ownership by Management and Principal Stockholders. On April 30, 1997,
directors and officers of the Company and certain principal stockholders and
their affiliates beneficially owned in the aggregate 2,087,084 shares of Common
Stock, representing 26.5% of the outstanding shares of Common Stock.
Accordingly, they have the ability to influence significantly the affairs of the
Company and matters requiring a stockholder vote, including the election of the
Company's directors, the amendment of the Company's charter documents, the
merger or dissolution of the Company and the sale of all or substantially all of
the Company's assets. The voting power of these holders may also discourage or
prevent any proposed takeover of the Company pursuant to a tender offer.
    

                                      -12-






                                 USE OF PROCEEDS

     The Company will not receive any proceeds from the sale of the shares of
Common Stock by the Selling Stockholders. The proceeds, if any, received by the
Company upon the exercise of the Warrants will be utilized by the Company for
working capital purposes.
       
                              SELLING STOCKHOLDERS
   
     The following table sets forth information as of March 31, 1997 except as
otherwise noted, with respect to the number of shares of Common Stock
beneficially owned by each of the Selling Stockholders. No Selling Stockholder
will beneficially own more than one percent of the outstanding Common Stock upon
consummation of the offering contemplated hereby, except Biotechnology
Investment Group, L.L.C. which will beneficially own approximately 5.56% of the
outstanding Common Stock upon consummation of the offering.
    
Number of Number of Shares of Shares of Common Stock Common Stock Selling Beneficially Registered Stockholder Owned Herein - ----------- ------------ ------------- Allen & Company, Inc (1) ............................................. 18,998 18,998 Benjamin M. Schaffer and Marlene Y. Schaffer, as Joint Tenants (2) ... 4,833 1,333 David Thalheim (3) ................................................... 5,000 5,000 Alber Balik (4) ...................................................... 16,666 16,666 Erica Jesselson, Michael G. Jesselson and Joseph Levine, Trustees UIT 8/21/74 M/B Benjamin J. Jesselson (5) ................. 8,332 8,332 Erica Jesselson, Michael G. Jesselson and Joseph Levine, Trustees UIT 4/8/71 F/B/O Michael G. Jesselson (5) ................. 8,332 8,332 Erica Jesselson, Lucy Lang, Claire Strauss, Michael G. Jesselson, Benjamin J. Jesselson, Trustees, UID 12/18/80 F/B/O A. Daniel Jesselson (5) ......................... 8,332 8,332 Ludwig Jesselson (6) ................................................. 16,666 16,666 Stephen L. Ross (7) .................................................. 13,166 9,833 Amerindo Investment Advisors, Inc. (8) ............................... 33,332 33,332 Mary Cullen (9) ...................................................... 14,894 14,894 Bruce Allen (10) ..................................................... 29,374 29,374 Howard Lockwood and Eve Lockwood as Joint Tenants (11) ............... 9,999 9,999 Amerindo Technology Growth Fund (12) ................................. 142,405 142,405 Brad Butler (13) ..................................................... 3,905 781 Richard C. Lowery (14) ............................................... 9,374 9,374 Connecticut Innovations, Inc. (15) ................................... 27,302 27,302 Joseph Giamanco (16) ................................................. 781 781 Ronald Menello (17) .................................................. 4,686 4,686 Norman Sieden (18) ................................................... 3,124 3,124 David H. Berman, M.D. (19) ........................................... 4,686 4,686 Barbara & Michael Balsam JTROS (20) .................................. 4,686 4,686 Lawrence Chimerine (21) .............................................. 6,124 6,124 Lester J. Patrizi & Joanne Gottringe-Patrizi, M.D., as JTROS (22) .... 4,686 4,686 Joel Stuart (23) ..................................................... 4,686 3,124 Steven Altman (24) ................................................... 3,905 3,905 Schroders Incorporated (25) .......................................... 28,864 21,052 Susan Walker (26) .................................................... 3,905 3,905 J.F. Shea & Co., Inc., as Nominee 1993-18 (27) ....................... 41,776 35,526 Dan Smargon & Audrey Viterbi JTWROS (28) ............................. 12,500 12,500 The Andrew J. & Erna F. Viterbi Family Trust U/A 8/5/80 (29) ......... 57,500 25,000 John Benesch (30) .................................................... 500 500 Joshua Schein (31) ................................................... 2,000 2,000 Biotechnology Investment Group, L.L.C ................................ 697,575 206,075 Global Health Sciences Fund (32) ..................................... 466,776 241,776 Schroder Ventures Limited Partnership ................................ 16,842 16,842 Schroder Ventures U.S. Trust ......................................... 4,211 4,211
-13-
Number of Number of Shares of Shares of Common Stock Common Stock Selling Beneficially Registered Stockholder Owned Herein - ----------- ------------ ------------- Yale University ...................................................... 105,623 105,623 Erica Jesselson ...................................................... 93,750 93,750 Lawrence Zaslow (33) ................................................. 1,218 1,218 Esther Blech (34) .................................................... 15,624 15,624 David Blech (35) ..................................................... 47,078 47,078 D. Blech & Company, Inc. (36) ........................................ 73,229 73,229 Jonathon Stern (37) .................................................. 4,686 4,686 Avner Hacohen (38) ................................................... 3,750 3,750 David Kaufman (39) ................................................... 2,500 2,500 Tom Lanier (40) ...................................................... 2,343 781 Judson Cooper (41) ................................................... 2,878 2,878 Celestial Charitable Remainder Trust (42) ............................ 204,166 204,166 Freedom Charitable Trust (43) ........................................ 39,071 39,071 Blech Family Trust (44) .............................................. 37,500 37,500 Hannamarie Wirtz (45) ................................................ 4,686 4,686 Dr. Franz Wirtz (45) ................................................. 4,686 4,686 Carl Goldfisher (46) ................................................. 2,000 2,000
- ---------- (1) Of the 18,998 shares beneficially owned and registered by this Selling Stockholder, 3,124 Shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share and 3,374 Shares are issuable upon the exercise of Warrants to purchase Common Stock at an exercise price of $12.50 per share. (2) Of the 4,833 shares beneficially owned by this Selling Stockholder, 1,666 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. The 1,333 shares registered by this Selling Stockholder are issuable upon the exercise of such warrants. (3) The 5,000 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (4) Of the 16,666 shares beneficially owned and registered by this Selling Stockholder, 3,333 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (5) Of the 8,332 shares beneficially owned and registered by this Selling Stockholder, 1,666 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (6) Of the 16,666 shares beneficially owned and registered by this Selling Stockholder, 3,333 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (7) Of the 13,166 shares beneficially owned by this Selling Stockholder, the 9,833 shares registered herein are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (8) Of the 33,332 shares beneficially owned and registered by this Selling Stockholder, 6,666 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. The 26,666 shares registered by this Selling Stockholder do not include the 6,666 shares underlying the warrants. (9) Of the 14,894 shares beneficially owned and registered by this Selling Stockholder, 2,978 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (10) Of the 29,374 shares beneficially owned and registered by this Selling Stockholder, 5,874 shares are issu able upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. -14- - ---------- (11) Of the 9,999 shares beneficially owned and registered by this Selling Stockholder, 3,333 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. (12) Of the 142,405 shares beneficially owned and registered by this Selling Stockholder, 24,270 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. The 118,135 shares registered by this Selling Stockholder exclude the 24,270 shares underlying the warrants. (13) Of the 3,905 shares beneficially owned by this Selling Stockholder, the 781 shares registered herein are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (14) Of the 9,374 shares beneficially owned and registered by this Selling Stockholder, 3,124 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. (15) Of the 27,302 shares beneficially owned and registered by this Selling Stockholder, 6,250 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (16) The 781 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (17) Of the 4,686 shares beneficially owned and registered by this Selling Stockholder, 1,562 shares are issuable upon exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. (18) The 3,124 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (19) Of the 4,686 shares beneficially owned and registered by this Selling Stockholder, 1,562 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. (20) Of the 4,686 shares beneficially owned and registered by this Selling Stockholder, 1,562 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. (21) Of the 6,124 shares beneficially owned and registered by this Selling Stockholder, 781 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (22) Of the 4,686 shares beneficially owned and registered by this Selling Stockholder, 1,562 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. (23) Of the 4,686 shares beneficially owned by this Selling Stockholder, 1,562 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. The 3,124 shares registered by the Selling Stockholder do not include the 1,562 shares underlying the warrants. (24) Of the 3,905 shares beneficially owned and registered by this Selling Stockholder, 781 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (25) Of the 28,864 shares beneficially owned by this Selling Stockholder, 7,812 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. The 21,052 shares registered by the Selling Stockholder do not include the 7,812 shares underlying the warrants. -15- - ---------- (26) Of the 3,905 shares beneficially owned and registered by this Selling Stockholder, 781 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (27) Of the 41,776 shares beneficially owned by this Selling Stockholder, 6,250 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. The 35,526 shares registered by the Selling Stockholder do not include the 6,250 shares underlying the warrants. (28) The 12,500 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per shhare. (29) Of the 57,500 shares beneficially owned by this Selling Stockholder, 12,500 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. The 25,000 shares registered by the Selling Stockholder do not include the 12,500 shares underlying the warrants. (30) The 500 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of Warrants to purchase Common Stock at an exercise price of $7.50 per share. (31) The 2,000 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of Warrants to purchase Common Stock at an exercise price of $7.50 per share. (32) Of the 466,776 shares beneficially owned and registered by this Selling Stockholder, 31,250 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (33) The 1,218 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $12.50 per share. (34) The 15,624 shares beneficially owned and registered by the Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (35) The 47,078 shares beneficially owned and registered by the Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (36) Of the 73,229 shares beneficially owned and registered by the Selling Stockholder, 20,000 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share, and 53,229 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (37) Of the 4,686 shares beneficially owned and registered by the Selling Stockholder, 1,562 shares are issuable upon the exercise of warrants to purchase Common Stock of an exercise price of $7.50 per share. (38) The 3,750 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (39) The 2,500 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $12.50 per share. (40) Of the 2,343 shares beneficially owned by this Selling Stockholder, the 781 shares registered herein are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. -16- - ---------- (41) The 2,878 shares beneficially owned and registered by the Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (42) Of the 204,166 shares beneficially owned and registered by the Selling Stockholder, 54,166 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (43) Of the 39,071 shares beneficially owned and registered by this Selling Stockholder, 7,812 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (44) The 37,500 shares beneficially owned and registered by this Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. (45) Of the 4,686 shares beneficially owned and registered by this Selling Stockholder, 1,562 shares are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $15.00 per share. (46) The 2,000 shares beneficially owned and registered by the Selling Stockholder are issuable upon the exercise of warrants to purchase Common Stock at an exercise price of $7.50 per share. PLAN OF DISTRIBUTION The distribution of the shares of Common Stock by the Selling Stockholders may be effected from time to time in one or more transactions (which may involve block transactions) in the over-the-counter market or on NASDAQ (or any exchange on which the Common Stock may then be listed) in negotiated transactions, through the writing of options (whether such options are listed on an options exchange or otherwise), or a combination of such methods of sale, at market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices. The Selling Stockholders may effect such transactions by selling shares to or through broker-dealers, and such broker-dealer may receive compensation in the form of underwriting discounts, concessions or commissions from the Selling Stockholders and/or purchasers of shares for whom they may act as agent (which compensation may be in excess of customary commissions). The Selling Stockholders may also sell such shares pursuant to Rule 144 promulgated under the Securities Act, or may pledge shares as collateral for margin accounts and such shares could be resold pursuant to the terms of such accounts. The Selling Stockholders and any broker-dealers that act in connection with the sale of the Common Stock might be deemed to be "underwriters" within the meaning of Section 2(11) of the Securities Act and any commission received by them and any profit on the resale of the shares of Common Stock as principal might be deemed to be underwriting discounts and commissions under the Securities Act. The Selling Stockholders may agree to indemnify any agent, dealer or broker-dealer that participates in transactions involving sales of the shares against certain liabilities, including liabilities arising under the Securities Act. Because the Selling Stockholders may be deemed to be "underwriters" within the meaning of Section 2(11) of the Securities Act, the Selling Stockholders will be subject to prospectus delivery requirements under the Securities Act. Furthermore, in the event of a "distribution" of the shares, such Selling Stockholders, any selling broker or dealer and any "affiliated purchasers" may be subject to Rule 10b-6 under the Exchange Act or Regulation M promulgated thereunder, which prohibits, with certain exceptions, any such person from bidding for or purchasing any security which is the subject of such distribution until his participation in that distribution is completed. In addition, Rule 10b-7 under the Exchange Actor Regulation M promulgated thereunder, prohibits any "stabilizing bid" or "stabilizing purchase" for the purpose of pegging, fixing or stabilizing the price of Common Stock in connection with this offering. In order to comply with certain state securities laws, if applicable, the Common Stock will not be sold in a particular state unless such securities have been registered or qualified for sale in such state or any exemption from registration or qualification is available and complied with. -17- The Company will not receive any of the proceeds from the sale of Common Stock by the Selling Stockholders. The proceeds, if any, from the exercise of the Warrants will be received by the Company; no brokerage commissions or discounts will be paid in connection therewith. LEGAL MATTERS The validity of the issuance of the shares of Common Stock offered hereby will be passed upon for the Company by Fulbright & Jaworski L.L.P., New York, New York. EXPERTS The audited financial statements incorporated by reference in this Prospectus and elsewhere in the Registration Statement have been audited by Arthur Andersen LLP, independent public accountants, as indicated in their report with respect thereto, and is incorporated herein in reliance upon the authority of said firm as experts in giving said report. -18- PART II ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION. The following table sets forth the Company's estimates (other than the SEC registration fee) of the expenses in connection with the issuance and distribution of the shares of Common Stock being registered: SEC registration fee ...................... $ 5,273.00 Legal fees and expenses ................... $40,000.00 Accounting fees and expenses .............. $10,000.00 Miscellaneous expenses .................... $ 9,727.00 ---------- Total ................................... $65,000.00 ========== ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS. Section 145 of the Delaware General Corporation Law (the "DGCL") empowers a Delaware corporation to indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of such corporation) by reason of the fact that such person is or was a director, officer, employee or agent of such corporation, or is or was serving at the request of such corporation as a director, officer, employee or agent of another corporation or enterprise. A corporation may, in advance of the final disposition of any civil, criminal, administrative or investigative action, suit or proceeding, pay the expenses (including attorneys' fees) incurred by any officer, director, employee or agent in defending such action, provided that the director or officer undertakes to repay such amount if it shall ultimately be determined that he is not entitled to be indemnified by the corporation. A corporation may indemnify such person against expenses (including attorneys' fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with such action, suit or proceeding if he acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his conduct was unlawful. A Delaware corporation may indemnify officers and directors in an action by or in the right of the corporation to procure a judgment in its favor under the same conditions, except that no indemnification is permitted without judicial approval if the officer or director is adjudged to be liable to the corporation. Where an officer or director is successful on the merits or otherwise in the defense of any action referred to above, the corporation must indemnify him against the expenses (including attorneys' fees) which he actually and reasonably incurred in connection therewith. The indemnification provided is not deemed to be exclusive of any other rights to which an officer or director may be entitled under any corporation's by-law, agreement, vote or otherwise. In accordance with Section 145 of the DGCL, Section EIGHTH of the Company's Certificate of Incorporation, as amended (the "Certificate") provides that the Company shall indemnify each person who is or was a director, officer, employee or agent of the Company (including the heirs, executors, administrators or estate of such person) or is or was serving at the request of the Company as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, to the fullest extent permitted. The indemnification provided by the Certificate shall not be deemed exclusive of any other rights to which any of those seeking indemnification or advancement of expenses may be entitled under any by-law, agreement, vote of shareholders or disinterested directors or otherwise, both as to action in his official capacity and as to action in another capacity while holding such office, and shall continue as to a person who has ceased to be a director, officer, employee or agent and shall inure to the benefit of the heirs, executors and administrators of such a person. Expenses (including attorneys' fees) incurred in defending a civil, criminal, administrative or investigative action, suit or proceeding shall be paid by the Company in advance of the final disposition of such action, suit or proceeding upon receipt of an undertaking by or on behalf of the indemnified person to repay such amount if it shall ultimately II-1 be determined that he is not entitled to be indemnified by the Company. Section NINTH of the Certificate provides that a director of the Company shall not be personally liable to the Company or its stockholders for monetary damages for breach of fiduciary duty as a director, except for liability (i) for any breach of the director's duty of loyalty to the Company or its stockholders, (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) under Section 174 of the DGCL, or (iv) for any transaction from which the director derived an improper personal benefit. II-2 ITEM 16. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES. (a) Exhibits. 3.1 Certificate of Incorporation, as amended.* 3.2 Bylaws.* 4.1 Specimen Common Stock Certificate.* 5.1 Opinion of Fulbright & Jaworski L.L.P. regarding legality.*** 10.1 Employment Agreement, dated April 1, 1997, between the Company and Dr. Leonard Bell.*** 10.2 Employment Agreement, dated June 1992, between the Company and David Keiser, as amended.* 10.3 Employment Agreement, dated March 1992, between the Company and Dr. Stephen P. Squinto, as amended.* 10.4 Employment Agreement, dated September 1992, between the Company and Dr. Louis A. Matis, as amended.* 10.5 Employment Agreement, dated July 1993, between the Company and Dr. James A. Wilkins, as amended.* 10.6 Employment Agreement, dated July 1994, between the Company and Dr. Bernadette Alford, as amended.* 10.7 Administrative Facility Lease, dated August 23, 1995, between the Company and Science Park Development Corporation.* 10.8 Research and Development Facility Lease, dated August 23, 1995, between the Company and Science Park Development Corporation.* 10.9 Option Agreement, dated April 1, 1992 between the Company and Dr. Leonard Bell.* 10.10 Company's 1992 Stock Option Plan, as amended.* 10.11 Company's 1992 Outside Directors Stock Option Plan, as amended.* 10.12 Registration Agreement, dated December 4, 1992, by the Company for the benefit of certain individuals listed on schedules thereto, as amended.* 10.13 Amendment to Registration Agreement, dated July 31, 1995, between the Company and United States Surgical Corporation.* 10.14 Agreement, dated June 15, 1993, by the Company for the benefit of certain individuals listed on schedules thereto, as amended.* 10.15 Form of Investor Rights Agreement, dated December 23, 1994, between the Company and the purchasers of the Company's Series A Preferred Stock, as amended.* 10.16 Stock Purchase Agreement, dated July 31, 1995, between the Company and United States Surgical Corporation.* 10.17 Form of Warrant to purchase shares of the Company's Common Stock issued pursuant to certain of the Company's private placements.* II-3 10.18 Form of Warrant to purchase shares of the Company's Common Stock issued to the Placement Agent of certain of the Company's private placements.* 10.19 Form of Warrant to purchase shares of the Company's Common Stock issued to certain warrantholders of the Company in connection with a Warrant Exchange.* 10.20 License Agreement dated as of May 27, 1992 between the Company and Yale University, as amended September 23, 1992.*+ 10.21 Exclusive License Agreement dated as of June 19, 1992 among the Company, Yale University and Oklahoma Medical Research Foundation.** 10.22 Research & Development Agreement dated as of June 19, 1992 between the Company and Oklahoma Medical Research Foundation.*+ 10.23 License Agreement dated as of September 30, 1992 between the Company and Yale University, as amended July 2, 1993.*+ 10.24 License Agreement dated as of August 1, 1993 between the Company and Biotechnology Research and Development Corporation ("BRDC"), as amended as of July 1, 1995.*+ 10.25 Cooperative Research and Development Agreement dated December 10, 1993 between the Company and the National Institutes of Health.*+ 10.26 License Agreement dated January 25, 1994 between the Company and The Austin Research Institute.*+ 10.27 Exclusive Patent License Agreement dated April 21, 1994 between the Company and the National Institutes of Health.*+ 10.28 License Agreement dated July 22, 1994 between the Company and The Austin Research Institute.*+ 10.29 License Agreement dated as of January 10, 1995 between the Company and Yale University.*+ 10.30 Joint Development Agreement dated as of July 31, 1995 between the Company and United States Surgical Corporation.*+ 10.31 Advanced Technology Program ("ATP"), Cooperative Agreement 70NANB5H, National Institute of Standards and Technology, entitled "Universal Donor Organs for Transplantation," dated September 15, 1995.*+ 10.32 U.S. Department of Health and Human Services, National Heart, Lung and Book Institute, Small Business Research Program, Phase II Grant Application, entitled "Role of Complement Activation in Cardiopulmonary Bypass," dated December 14, 1994; and Notice of Grant Award dated September 21, 1995.*+ 10.33 Research Subcontract Agreement dated as of October 1, 1995 between the Company and Tufts University.*+ 10.34 Agreement to be Bound by Shareholders Agreement dated as of August 1, 1993 between the Company and BRDC.* 10.35 Agreement to be Bound by Master Agreement dated as of August 1, 1993 between the Company and BRDC.* II-4 10.36 Research and Development Facility Lease, dated April 1, 1996, between the Company and Science Park Development Corporation.** 10.37 License Agreement dated March 27, 1996 between the Company and Medical Research Council.**++ 10.38 License Agreement dated May 8, 1996 between the Company and Enzon, Inc.**+ 10.39 License and Collaborative Research Agreement between Alexion Pharmaceuticals, Inc. and Genetic Therapy, Inc.***+ 23.1 Consent of Fulbright & Jaworski L.L.P. (included in Exhibit 5) 23.2 Consent of Arthur Andersen LLP - ---------- * Incorporated by reference to the Company's Registration Statement on Form S-1, (Reg. No. 333-00202). ** Incorporated by reference to the Company's Annual report on Form 10-K for the fiscal year ended July 31, 1996. *** Previously filed. + Confidential treatment was granted for portions of such document. ++ A request for confidential treatment has been made for portions of such document, Confidential Portions have been omitted and filed separately with the Commission as required by Rule 406(b). (b) Financial Statement Schedules Not Applicable ITEM 17. UNDERTAKINGS. (a) The undersigned Registrant hereby undertakes: (1) To file, during any period in which offers or sales are being made, a post-effective amendment of this registration statement: (i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933; (ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement; (iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement of any material change to such information in the registration statement; II-5 Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement. (2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. (3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering. (b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. (c) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the provisions described under Item 15 above, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue. II-6 SIGNATURES PURSUANT TO THE REQUIREMENTS OF THE SECURITIES ACT OF 1933, AS AMENDED, THE REGISTRANT HAS DULY CAUSED THIS REGISTRATION STATEMENT TO BE SIGNED ON ITS BEHALF BY THE UNDERSIGNED, THEREUNTO DULY AUTHORIZED, IN THE CITY OF NEW HAVEN AND STATE OF CONNECTICUT ON THE 18TH DAY OF JULY, 1997. ALEXION PHARMACEUTICALS, INC. By: /s/ LEONARD BELL --------------------------------- Leonard Bell, M.D. President, Chief Executive Officer, Secretary and Treasurer POWER OF ATTORNEY KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature appears below constitutes and appoints LEONARD BELL, M.D. and DAVID W. KEISER, or either of them, his true and lawful attorney-in-fact and agent with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement, and to file the same with all exhibits thereto, and all documents in connection therewith, with the Securities and Exchange Commission, granting said attorney-in-fact and agent, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent or any of them, or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof. Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated: /s/ LEONARD BELL President, Chief Executive Officer, July 18, 1997 - ------------------------------- Secretary, Treasurer and Director Leonard Bell, M.D. (principal executive officer) /s/ DAVID W. KEISER Executive Vice President and July 18, 1997 - ------------------------------- Chief Operating Officer David W. Keiser (principal financial officer) /s/ BARRY P. LUKE Senior Director of Finance July 18, 1997 - ------------------------------- and Administration (principal Barry P. Luke accounting officer) /s/ JOHN H. FRIED - ------------------------------- Chairman of the Board of Directors July 18, 1997 John H. Fried, Ph.D. * - ------------------------------- Director July 18, 1997 Joseph A. Madri, Ph.D., M.D. /s/ LEONARD MARKS - ------------------------------- Director July 18, 1997 Leonard Marks, Jr., Ph.D. * - ------------------------------- Director July 18, 1997 Max Link, Ph.D. /s/ EILEEN MORE - ------------------------------- Director July 18, 1997 Eileen M. More /s/ TIMOTHY F. HOWE Director July 18, 1997 - ------------------------------- Timothy F. Howe
*By: /s/ LEONARD BELL, M.D. ---------------------- Leonard Bell, M.D. (Attorney-in-fact for each of the persons indicated) II-7 EXHIBIT INDEX Exhibit Number Exhibit - ------ ------- 3.1 Certificate of Incorporation, as amended.* 3.2 Bylaws.* 4.1 Specimen Common Stock Certificate.* 5.1 Opinion of Fulbright & Jaworski L.L.P. regarding legality.*** 10.1 Employment Agreement, dated April 1, 1997, between the Company and Dr. Leonard Bell.*** 10.2 Employment Agreement, dated June 1992, between the Company and David Keiser, as amended.* 10.3 Employment Agreement, dated March 1992, between the Company and Dr. Stephen P. Squinto, as amended.* 10.4 Employment Agreement, dated September 1992, between the Company and Dr. Louis A. Matis, as amended.* 10.5 Employment Agreement, dated July 1993, between the Company and Dr. James A. Wilkins, as amended.* 10.6 Employment Agreement, dated July 1994, between the Company and Dr. Bernadette Alford, as amended.* 10.7 Administrative Facility Lease, dated August 23, 1995, between the Company and Science Park Development Corporation.* 10.8 Research and Development Facility Lease, dated August 23, 1995, between the Company and Science Park Development Corporation.* 10.9 Option Agreement, dated April 1, 1992 between the Company and Dr. Leonard Bell.* 10.10 Company's 1992 Stock Option Plan, as amended.* 10.11 Company's 1992 Outside Directors Stock Option Plan, as amended.* 10.12 Registration Agreement, dated December 4, 1992, by the Company for the benefit of certain individuals listed on schedules thereto, as amended.* 10.13 Amendment to Registration Agreement, dated July 31, 1995, between the Company and United States Surgical Corporation.* 10.14 Agreement, dated June 15, 1993, by the Company for the benefit of certain individuals listed on schedules thereto, as amended.* 10.15 Form of Investor Rights Agreement, dated December 23, 1994, between the Company and the purchasers of the Company's Series A Preferred Stock, as amended.* 10.16 Stock Purchase Agreement, dated July 31, 1995, between the Company and United States Surgical Corporation.* 10.17 Form of Warrant to purchase shares of the Company's Common Stock issued pursuant to certain of the Company's private placements.* 10.18 Form of Warrant to purchase shares of the Company's Common Stock issued to the Placement Agent of certain of the Company's private placements.* 10.19 Form of Warrant to purchase shares of the Company's Common Stock issued to certain warrantholders of the Company in connection with a Warrant Exchange.* 10.20 License Agreement dated as of May 27, 1992 between the Company and Yale University, as amended September 23, 1992.*+ 10.21 Exclusive License Agreement dated as of June 19, 1992 among the Company, Yale University and Oklahoma Medical Research Foundation.** 10.22 Research & Development Agreement dated as of June 19, 1992 between the Company and Oklahoma Medical Research Foundation.*+ 10.23 License Agreement dated as of September 30, 1992 between the Company and Yale University, as amended July 2, 1993.*+ 10.24 License Agreement dated as of August 1, 1993 between the Company and Biotechnology Research and Development Corporation ("BRDC"), as amended as of July 1, 1995.*+ 10.25 Cooperative Research and Development Agreement dated December 10, 1993 between the Company and the National Institutes of Health.*+ 10.26 License Agreement dated January 25, 1994 between the Company and The Austin Research Institute.*+ 10.27 Exclusive Patent License Agreement dated April 21, 1994 between the Company and the National Institutes of Health.*+ 10.28 License Agreement dated July 22, 1994 between the Company and The Austin Research Institute.*+ 10.29 License Agreement dated as of January 10, 1995 between the Company and Yale University.*+ 10.30 Joint Development Agreement dated as of July 31, 1995 between the Company and United States Surgical Corporation.*+ 10.31 Advanced Technology Program ("ATP"), Cooperative Agreement 70NANB5H, National Institute of Standards and Technology, entitled "Universal Donor Organs for Transplantation," dated September 15, 1995.*+ 10.32 U.S. Department of Health and Human Services, National Heart, Lung and Book Institute, Small Business Research Program, Phase II Grant Application, entitled "Role of Complement Activation in Cardiopulmonary Bypass," dated December 14, 1994; and Notice of Grant Award dated September 21, 1995.*+ 10.33 Research Subcontract Agreement dated as of October 1, 1995 between the Company and Tufts University.*+ 10.34 Agreement to be Bound by Shareholders Agreement dated as of August 1, 1993 between the Company and BRDC.* 10.35 Agreement to be Bound by Master Agreement dated as of August 1, 1993 between the Company and BRDC.* 10.36 Research and Development Facility Lease, dated April 1, 1996, between the Company and Science Park Development Corporation.** 10.37 License Agreement dated March 27, 1996 between the Company and Medical Research Council.**++ 10.38 License Agreement dated May 8, 1996 between the Company and Enzon, Inc.**+ 10.39 License and Collaborative Research Agreement between Alexion Pharmaceuticals, Inc. and Genetic Therapy, Inc.***+ 23.1 Consent of Fulbright & Jaworski L.L.P. (included in Exhibit 5) 23.2 Consent of Arthur Andersen LLP - ---------- * Incorporated by reference to the Company's Registration Statement on Form S-1, (Reg. No. 333-00202). ** Incorporated by reference to the Company's Annual report on Form 10-K for the fiscal year ended July 31, 1996. *** Previously filed. + Confidential treatment was granted for portions of such document. ++ A request for confidential treatment has been made for portions of such document, Confidential Portions have been omitted and filed separately with the Commission as required by Rule 406(b).

                              ARTHUR ANDERSEN LLP



                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS
                    ----------------------------------------


As independent public accountants, we hereby consent to the incorporation by
reference in this registration statement of our report dated August 30, 1996
included in Alexion Pharmaceuticals, Inc.'s Form 10-K for the year ended
July 31, 1996 and to all references to our Firm included in this registration
statement.


/s/ ARTHUR ANDERSEN LLP

Hartford, Connecticut
July 15, 1997