Alexion Pharmaceuticals, Inc.
ALEXION PHARMACEUTICALS INC (Form: 4, Received: 11/23/2004 15:39:13)
FORM 4
[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
                                                                                  
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public
Utility Holding Company Act of 1935 or Section 30(f) of the Investment Company Act of 1940
                      

1. Name and Address of Reporting Person *

BELL LEONARD
2. Issuer Name and Ticker or Trading Symbol

ALEXION PHARMACEUTICALS INC [ ALXN ]
5. Relationship of Reporting Person(s) to Issuer (Check all applicable)

__ X __ Director                      _____ 10% Owner
__ X __ Officer (give title below)      _____ Other (specify below)
Chief Executive Officer
(Last)          (First)          (Middle)

C/O ALEXION PHARMACEUTICALS INC, 352 KNOTTER DRIVE
3. Date of Earliest Transaction (MM/DD/YYYY)

11/22/2004
(Street)

CHESHIRE, CT 06410
(City)        (State)        (Zip)
4. If Amendment, Date Original Filed (MM/DD/YYYY)

 
6. Individual or Joint/Group Filing (Check Applicable Line)

_ X _ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Trans. Date 2A. Deemed Execution Date, if any 3. Trans. Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Common Stock, par value $.0001   11/22/2004     M    5791   A $2.375   261103   D    
Common Stock, par value $.0001   11/22/2004     M    37959   A $2.375   299062   D    
Common Stock, par value $.0001   11/22/2004     S    200   D $20.57   298862   D    
Common Stock, par value $.0001   11/22/2004     S    500   D $20.54   298362   D    
Common Stock, par value $.0001   11/22/2004     S    600   D $20.52   297762   D    
Common Stock, par value $.0001   11/22/2004     S    100   D $20.5   297662   D    
Common Stock, par value $.0001   11/22/2004     S    100   D $20.49   297562   D    
Common Stock, par value $.0001   11/22/2004     S    500   D $20.48   297062   D    
Common Stock, par value $.0001   11/22/2004     S    635   D $20.47   296427   D    
Common Stock, par value $.0001   11/22/2004     S    200   D $20.46   296227   D    
Common Stock, par value $.0001   11/22/2004     S    2165   D $20.45   294062   D    
Common Stock, par value $.0001   11/22/2004     S    100   D $20.35   293962   D    
Common Stock, par value $.0001   11/22/2004     S    1000   D $20.32   292962   D    
Common Stock, par value $.0001   11/22/2004     S    300   D $20.31   292662   D    
Common Stock, par value $.0001   11/22/2004     S    3600   D $20.3   289062   D    
Common Stock, par value $.0001   11/22/2004     S    100   D $20.29   288962   D    
Common Stock, par value $.0001   11/22/2004     S    100   D $20.28   288862   D    
Common Stock, par value $.0001   11/22/2004     S    100   D $20.27   288762   D    
Common Stock, par value $.0001   11/22/2004     S    200   D $20.26   288562   D    
Common Stock, par value $.0001   11/22/2004     S    4500   D $20.25   284062   D    
Common Stock, par value $.0001   11/22/2004     S    10000   D $20.2   274062   D    

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Trans. Date 3A. Deemed Execution Date, if any 4. Trans. Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
6. Date Exercisable and Expiration Date 7. Title and Amount of Securities Underlying Derivative Security
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Option to Purchase Common Stock, par value $.0001   $2.375   11/22/2004           5791    5/1/1999   5/1/2005   Common Stock, par value $.0001   5791   $0   0   D    
Option to Purchase Common Stock, par value $.0001   $2.375   11/22/2004           37959    5/1/1999   5/1/2005   Common Stock, par value $.0001   37959   $0   29749   D    

Explanation of Responses:

Remarks:
The sales reported by this Form 4 are made pursuant to the terms of a Sales Plan designed to meet the requirements of Rule 10b5-1 (c) (1) of the Securities Exchange Act.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director 10% Owner Officer Other
BELL LEONARD
C/O ALEXION PHARMACEUTICALS INC
352 KNOTTER DRIVE
CHESHIRE, CT 06410
X
Chief Executive Officer

Signatures
/s/ Dr. Leonard Bell 11/23/2004
** Signature of Reporting Person Date


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* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
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