8-K

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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                                    FORM 8-K

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                                 CURRENT REPORT
                     PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934


Date of Report (Date of earliest event reported) September 9, 1997
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                         ALEXION PHARMACEUTICALS, INC.
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             (Exact Name of Registrant as Specified in its Charter)


         Delaware                    0-27756                   13-3648318
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(State or Other Jurisdiction       (Commission               (IRS Employer
     of Incorporation)             File Number)            Identification No.)


     25 Science Park, New Haven, CT                        06511
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(Address of Principal Executive Offices)                 (Zip Code)


Registrant's telephone number, including area code: (203) 776-1790
                                                   ------------------

                                 Not Applicable
          -------------------------------------------------------------
          (Former Name or Former Address, if Changed Since Last Report)








ITEM 5.  OTHER EVENTS

     On September 9, 1997, Alexion Pharmaceuticals, Inc. issued the press
release filed herewith as Exhibit 99.


ITEM 7.  FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS.

      (c)  EXHIBITS.

      99. Press Release dated September 9, 1997.









                                   SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                       ALEXION PHARMACEUTICALS, INC.

Date: September 10, 1997               By: /s/ LEONARD BELL
                                           ----------------------
                                       Name:  Leonard Bell, M.D.
                                       Title: President, Chief Executive
                                              Officer, Secretary and Treasurer

EX-99

                                                                      Exhibit 99

IMMEDIATE RELEASE


      Contact: Leonard Bell, M.D.                     Rhonda Chiger (Investor)
               President and CEO                      Susan Farley (Media)
               Alexion Pharmaceuticals                Dewe Rogerson Inc.
               203/776-1790                           212/688-6840


               ALEXION RECEIVES $10 MILLION IN PRIVATE PLACEMENT

New Haven, CT, September 9, 1997 --- Alexion Pharmaceuticals, Inc. (Nasdaq:
ALXN) today announced that it has closed a private placement of $10.0 million in
stock to a single institutional investor, BB Biotech. Robertson, Stephens &
Company LLC served as Advisor in the transaction.

"We are gratified to add BB Biotech as a significant new shareholder. In
addition to the $11.2 million raised in July, 1997, we believe that these
proceeds will allow us to further augment the clinical development of our lead
C5 complement inhibitors and more broadly advance the manufacturing, preclinical
development and clinical development of our portfolio of product candidates,"
said Dr. Bell, President and Chief Executive Officer of Alexion.

BB Biotech purchased 400,000 shares of Series B Preferred Stock at $25.00 per
share, convertible automatically in six months, or at the election of the holder
at any time after the date of issuance, into 935,782 shares of common stock at
$10.686 per share. The conversion price represents a 3% premium to the closing
bid of $10.375 on the day of pricing. The Series B Preferred Stock will pay a
dividend of $2.25 per share of Series B Preferred Stock on March 4, 1998,
payable in cash or common stock at the discretion of Alexion. Proceeds from the
private placement will be used to fund the Company's research and development
activities including ongoing and planned clinical studies, production of
clinical trial material, preclinical studies, and for general corporate
purposes.

Alexion Pharmaceuticals, Inc. was founded in 1992 and is engaged in the
development of selective immunotherapeutic drugs that generally are designed to
inhibit the disease-causing segments of the immune system while preserving the
disease-preventing aspects of the immune system. The Company is developing three
technology platforms: C5 Complement Inhibitors and Apogen T-Cell Therapeutics
which together target severe cardiovascular and autoimmune disorders; and
xenografts for organ transplants.

This news release contains forward looking statements. Such statements are
subject to certain factors which may cause Alexion's plans to differ or results
to vary from those expected including unexpected preclinical or clinical
results, the need for additional research and testing, delays in manufacturing,
access to capital and funding, delays in development of commercial relationships
and a variety of risks set forth from






time to time in Alexion's filings with the Securities and Exchange Commission,
including but not limited to Alexion's Annual Report on Form 10-K for the year
ended July 31, 1996 and those risks as discussed in Alexion's Registration
Statement (Registration No. 333-29617). Alexion undertakes no obligations to
publicly release the results of any of these forward looking statements which
may be made to reflect events or circumstances after the date hereof or to
reflect the occurrence of unanticipated events. The shares of Preferred Stock
and the Common Stock into which the Preferred Stock may be converted, have not
been registered under the Securities Act of 1933, as amended, and may not be
offered and sold in the United States absent registration under such Act or an
applicable exemption from registration. This press release shall not constitute
an offer to sell or the solicitation of an offer to buy the capital stock of the
Company nor shall there be any sale of these securities in any state in which
such offer, solicitation or sale would be unlawful prior to registration or
qualification under the securities laws of any such state.