-----BEGIN PRIVACY-ENHANCED MESSAGE----- Proc-Type: 2001,MIC-CLEAR Originator-Name: webmaster@www.sec.gov Originator-Key-Asymmetric: MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB MIC-Info: RSA-MD5,RSA, MnTnSfnEfZagSvTKcYQ5dd9n3nC8i5wZeSHq3nVDRukFScoXfFgrsC7nV8TbDLD4 SdK4md8N2ENrX1/n9Gs7Zg== 0000912057-02-019913.txt : 20020513 0000912057-02-019913.hdr.sgml : 20020513 ACCESSION NUMBER: 0000912057-02-019913 CONFORMED SUBMISSION TYPE: SC 13G PUBLIC DOCUMENT COUNT: 1 FILED AS OF DATE: 20020513 SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: ICOS CORP / DE CENTRAL INDEX KEY: 0000874294 STANDARD INDUSTRIAL CLASSIFICATION: PHARMACEUTICAL PREPARATIONS [2834] IRS NUMBER: 911463450 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13G SEC ACT: 1934 Act SEC FILE NUMBER: 005-48079 FILM NUMBER: 02644175 BUSINESS ADDRESS: STREET 1: 22021-20TH AVENUE S.E., CITY: BOTHELL STATE: WA ZIP: 98021 BUSINESS PHONE: 2064851900 MAIL ADDRESS: STREET 1: 22021 20TH AVE SE CITY: BOTHELL STATE: WA ZIP: 98021 FILED BY: COMPANY DATA: COMPANY CONFORMED NAME: PRIMECAP MANAGEMENT CO/CA/ CENTRAL INDEX KEY: 0000763212 IRS NUMBER: 953868081 FILING VALUES: FORM TYPE: SC 13G BUSINESS ADDRESS: STREET 1: 225 SOUTH LAKE AVE STE 400 CITY: PASADENA STATE: CA ZIP: 91101-3005 BUSINESS PHONE: 8183049222 MAIL ADDRESS: STREET 1: 225 SOUTH LAKE AVE SUITE 400 CITY: PASADENA STATE: CA ZIP: 91101 SC 13G 1 a2079656zsc13g.htm SC 13G
QuickLinks -- Click here to rapidly navigate through this document

   
OMB APPROVAL
    OMB Number: 3235-0145
    Expires: December 31, 1997
    Estimated average burden
    hours per response 14.90
   

 
 
 
 

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

        Under the Securities Exchange Act of 1934

(Amendment No.    )*


 
 
ICOS CORP.
(Name of Issuer)
 
 

 
 
 
 
 
    Common
(Title of Class of Securities)		    

 
 
 
 
 
    449295104
(CUSIP Number)		    

 
 
 
 
 

Check the following box if a fee is being paid with this statement o. (A fee is not required only if the filing person: (1) has a previous statement on file reporting beneficial ownership of more than five percent of the class of securities described in Item 1; and (2) has filed no amendment subsequent thereto reporting beneficial ownership of five percent or less of such class.) (See Rule 13d-7).

* 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.)

Page 1 of 4 pages
 
 
 
 
CUSIP No. 449295104   13G    
       

1.   NAME OF REPORTING PERSON
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON		    

 
 
PRIMECAP Management Company                        95-3868081
 
 
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*    
        (a) o
        (b) o
3.   SEC USE ONLY    

 
 
 
 
 
4.   CITIZENSHIP OR PLACE OF ORGANIZATION    

 
 
225 South Lake Avenue #400, Pasadena, CA 91101
 
 
  5.   SOLE VOTING POWER
NUMBER OF     1,122,400
SHARES
BENEFICIALLY 6.   SHARED VOTING POWER
OWNED BY     -0-
EACH
REPORTING 7.   SOLE DISPOSITIVE POWER
PERSON     3,511,100
WITH
  8.   SHARED DISPOSITIVE POWER
      -0-
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON    

 
 
3,511,100
 
 
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*    

 
 
 
 
o
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9    

 
 
5.85%
 
 
12.   TYPE OF REPORTING PERSON*    

 
 
IA
 
 
*SEE INSTRUCTION BEFORE FILLING OUT!

Page 2 of 4 pages

    (c)
    Number of shares as to which such person has:

    (i)
    sole power to vote or to direct the vote

    (ii)
    shared power to vote or to direct the vote

    (iii)
    sole power to dispose or to direct the disposition of

    (iv)
    shared power to dispose or to direct the disposition of

Instruction: For computations regarding securities which represent a right to acquire an underlying security see Rule 13d-3(d)(1).


Item 5. Ownership of Five Percent or Less of a Class

        If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following o.

Instruction: Dissolution of a group requires a response to this item.


Item 6. Ownership of More than Five Percent on Behalf of Another Person.

        If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than five percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.


Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company

        If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c), attach an exhibit stating the identification of the relevant subsidiary.


Item 8. Identification and Classification of Members of the Group

        If a group has filed this schedule pursuant to Rule 13d-1(b)(ii)(H), so indicate under Item 3(h) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to Rule 13d-1(c), attach an exhibit stating the identity of each member of the group.


Item 9. Notice of Dissolution of Group

        Notice of dissolution of a group may be furnished as an exhibit stating the date of the dissolution and that all further filings with respect to transactions in the security reported on will be filed, if required, by members of the group, in their individual capacity. See Item 5.

Page 3 of 4 pages


Item 10. Certification

        The following certification shall be included if the statement is filed pursuant to Rule 13d-1(b):

        By signing below I certify that, to the best of knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purposes 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.

    April 30, 2002
Date

 
 
 
    /s/  THEO KOLOKOTRONES      
Signature

 
 
 
    Theo A. Kolokotrones, President
Name/Title

 
 
 

Page 4 of 4 pages



QuickLinks

SCHEDULE 13G
SIGNATURE
 -----END PRIVACY-ENHANCED MESSAGE-----