UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G/A
Under the Securities Exchange Act of 1934
Alexion Pharmaceuticals, Inc.
(Name of Issuer)
Common Stock
(Title of Class of Securities)
0015351109
(CUSIP Number)
December 31, 2002
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:
[x] Rule 13d-1(b)
[x] Rule 13d-1(c)
[ ] Rule 13d-1(d)
*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
CUSIP No. 0015351109
1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
OrbiMed Advisors Inc.
2. Check the Appropriate Box if a Member Of a Group (See Instructions)
[ ] (a)
[ ] (b)
3. SEC Use Only
4. Citizenship or Place of Organization
Delaware
5. Sole Voting Power: 0
Number of
Shares 6. Shared Voting Power: 797,500
Beneficially
Owned by 7. Sole Dispositive Power: 0
Each Reporting
Person With 8. Shared Dispositive Power: 797,500
9. Aggregate Amount Beneficially Owned by Each Reporting Person: 797,500
10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares
(See Instructions)
11. Percent of Class Represented by Amount in Row (9) 4.38%
12. Type of Reporting Person (See Instructions) IA
2
CUSIP No. 0015351109
1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
OrbiMed Advisors LLC
2. Check the Appropriate Box if a Member of a Group (See Instructions)
[ ] (a)
[ ] (b)
3. SEC Use Only
4. Citizenship or Place of Organization
Delaware
5. Sole Voting Power: 0
Number of
Shares 6. Shared Voting Power: 797,500
Beneficially
Owned by 7. Sole Dispositive Power: 0
Each Reporting
Person With 8. Shared Dispositive Power: 797,500
9. Aggregate Amount Beneficially Owned by Each Reporting Person: 797,500
10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares
(See Instructions)
11. Percent of Class Represented by Amount in Row (9) 4.38%
12. Type of Reporting Person (See Instructions) IA
3
CUSIP No. 0015351109
1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
OrbiMed Capital LLC
2. Check the Appropriate Box if a Member of a Group (See Instructions)
[ ] (a)
[ ] (b)
3. SEC Use Only
4. Citizenship or Place of Organization
Delaware
5. Sole Voting Power: 0
Number of
Shares 6. Shared Voting Power: 797,500
Beneficially
Owned by 7. Sole Dispositive Power: 0
Each Reporting
Person With 8. Shared Dispositive Power: 797,500
9. Aggregate Amount Beneficially Owned by Each Reporting Person: 797,500
10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares
(See Instructions)
11. Percent of Class Represented by Amount in Row (9) 4.38%
12. Type of Reporting Person (See Instructions) CO
4
CUSIP No. 0015351109
1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
Samuel D. Isaly
2. Check the Appropriate Box if a Member of a Group (See Instructions)
[ ] (a)
[ ] (b)
3. SEC Use Only
4. Citizenship or Place of Organization
United States
5. Sole Voting Power: 0
Number of
Shares 6. Shared Voting Power: 797,500
Beneficially
Owned by 7. Sole Dispositive Power: 0
Each Reporting
Person With 8. Shared Dispositive Power: 797,500
9. Aggregate Amount Beneficially Owned by Each Reporting Person: 797,500
10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares
(See Instructions)
11. Percent of Class Represented by Amount in Row (9) 4.38%
12. Type of Reporting Person (See Instructions) HC
5
Item 1. (a) Issuer: Alexion Pharmaceuticals, Inc.
(b) Address: 25 Science Park, Suite 360
New Haven, CT 06511
Item 2. (a) Name of Person Filing:
OrbiMed Advisors Inc.
OrbiMed Advisors LLC
OrbiMed Capital LLC
Samuel D. Isaly
(b) Address of Principal Business Offices:
767 Third Avenue, 30th Floor
New York, New York 10017
(c) Citizenship:
Please refer to Item 4 on each cover sheet for each filing person
(d) Title of Class of Securities
Common stock
(e) CUSIP Number: 0015351109
Item 3. OrbiMed Advisors Inc. and OrbiMed Advisors LLC are investment advisors
In accordance with ss.240.13d-1(b)(1)(ii)(E). Samule D. Isaly is a
control Person in accordance with ss.240.13d-1(b)(1)(ii)(G). Not
applicable to OrbiMed Capital LLC.
Item 4. Ownership
Please see Items 5 - 9 and 11 for each cover sheet for each filing
separately
Item 5. Ownership of Five Percent or Less of a Class
Reporting persons are holding 4.38% of the securities on behalf of
other persons who have the right to receive or the power to direct the
receipt of dividends from, or the proceeds from the sale of, such
securities.
Item 6. Ownership of More than Five Percent on Behalf of Another Person.
Not Applicable.
Item 7. Identification and Classification of the Subsidiary Which Acquired the
Security Being Reported on By the Parent Holding Company
Not Applicable
Item 8. Identification and Classification of Members of the Group
Not Applicable
Item 9. Notice of Dissolution of Group
Not Applicable
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Item 10. Certification
By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were not acquired and are not
held for the purpose of or with the effect of changing or influencing
the control of the issuer of the securities and were not acquired and
are not held in connection with or as a participant in any transaction
having that purpose or effect.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.
Date: February 14, 2003
OrbiMed Advisors Inc.
By: /s/ Samuel D. Isaly
------------------------------
Name: Samuel D. Isaly
Title: President
By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were acquired and held in the
ordinary course of business and were not acquired and are not held for
the purpose of or with the effect of changing or influencing the
control of the issuer of the securities and were not acquired and are
not held in connection with or as a participant in any transaction
having that purpose or effect.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.
Date: February 14, 2003
OrbiMed Advisors LLC
By: /s/ Samuel D. Isaly
------------------------------
Name: Samuel D. Isaly
Title: President of Managing
Member, OrbiMed Advisors Inc.
OrbiMed Capital LLC
By: /s/ Samuel D. Isaly
------------------------------
Name: Samuel D. Isaly
Title: Managing Member
By: /s/ Samuel D. Isaly
------------------------------
Name: Samuel D. Isaly
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