UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                  SCHEDULE 13G


                    Under the Securities Exchange Act of 1934
                              (Amendment No. 1)


                         La Jolla Pharmaceutical Company
--------------------------------------------------------------------------------
                                     (Name of Issuer)

                                  Common Stock
--------------------------------------------------------------------------------
                              (Title of Class of Securities)

                                    503459307
--------------------------------------------------------------------------------
                                      (CUSIP Number)

                               December 31, 2005
--------------------------------------------------------------------------------
                  (Date of Event which Required Filing of this Statement)


Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

[X]      Rule 13d-1(b)
|_|      Rule 13d-1(c)
|_|      Rule 13d-1(d)

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).






                                             SCHEDULE 13G

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

          Columbia Wanger Asset Management, L.P. 04-3519872

   2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP     (a) |_|
                                                               (b) [_]
          Not Applicable

   3      SEC USE ONLY

   4      CITIZENSHIP OR PLACE OF ORGANIZATION

          Delaware

                           5      SOLE VOTING POWER
                                  1,125,000
   NUMBER OF SHARES
BENEFICIALLY OWNED BY
EACH REPORTING PERSON
         WITH
                           6      SHARED VOTING POWER
                                   0

                           7      SOLE DISPOSITIVE POWER
                                  1,125,000

                           8      SHARED DISPOSITIVE POWER
                                  0

    9       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
            1,125,000

    10      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
            |_|

            Not Applicable

    11      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
            7.6%

    12      TYPE OF REPORTING PERSON
            IA



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

          WAM Acquisition GP, Inc.

   2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP     (a) |_|
                                                               (b) [_]
          Not Applicable

   3      SEC USE ONLY

   4      CITIZENSHIP OR PLACE OF ORGANIZATION

          Delaware

                           5      SOLE VOTING POWER
                                  0
   NUMBER OF SHARES
BENEFICIALLY OWNED BY
EACH REPORTING PERSON
         WITH
                           6      SHARED VOTING POWER
                                  1,125,000

                           7      SOLE DISPOSITIVE POWER
                                  0

                           8      SHARED DISPOSITIVE POWER
                                  1,125,000

    9       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
            1,125,000

    10      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
            |_|

            Not Applicable

    11      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
            7.6%

    12      TYPE OF REPORTING PERSON
            CO




Item 1.    (a).   Name of Issuer: La Jolla Pharmaceutical Company

           (b).   Address of Issuer's Principal Executive Offices:

                  6455 Nancy Ridge Drive
                  San Diego, CA  92121

Item 2.    (a).    Name of Person Filing:

                   Columbia Wanger Asset Management L.P. ("WAM")
                   WAM Acquisition GP, Inc., the general partner of WAM
                   ("WAM GP")

           (b). Address of Principal Business Office or, if none, Residence:

                WAM and WAM GP are both located at:

                227 West Monroe Street, Suite 3000
                Chicago, Illinois  60606

           (c). Citizenship or Place of Organization:

                WAM is a Delaware limited partnerhsip, WAM GP is a Delaware
                corporation.

           (d). Title of Class of Securities:

                Common Stock

           (e). CUSIP Number:

                503459307

Item 3.        If this statement is filed pursuant to sections  240.13d-1(b)  or
               240.13d-2(b) or (c), check whether the person filing is a:

               (a)[ ]    Broker or dealer registered under section 15 of the Act
                         (15 U.S.C. 78o);
               (b)[ ]    Bank  as  defined  in  section  3(a)(6)  of the Act (15
                         U.S.C. 78c);
               (c)[ ]    Insurance company as defined in section 3(a)(19) of the
                         Act (15 U.S.C. 78c.);
               (d)[ ]    Investment  company  registered  under section 8 of the
                         Investment Company Act of 1940 (15 U.S.C. 80a-8);
               (e)[X]    An  investment   adviser  in  accordance  with  section
                         240.13d-1(b)(1)(ii)(E) (WAM  is an  Investment  Adviser
                         registered under section 203 of the Investment Advisers
                         Act  of  1940;  WAM  GP is the  General Partner  of the
                         Investment Adviser.);
               (f)[ ]    An  employee   benefit  plan  or   endowment   fund  in
                         accordance with section 240.13d-1(b)(1)(ii) (F);
               (g)[ ]    A  parent   holding   company  or  control   person  in
                         accordance with section 240.13d-1(b)(1)(ii)(G);
               (h)[ ]    A savings  associations  as defined in section  3(b) of
                         the Federal Deposit Insurance Act (12 U.S.C. 1813);
               (i)[ ]    A church plan that is excluded  from the  definition of
                         an investment  company  under  section  3(c)(14) of the
                         Investment Company Act of 1940 (15 U.S.C. 80a-3);
               (j)[ ]    Group,  in  accordance  with  section   240.13d-1(b)(1)
                         (ii)(J).

       If this statement if filed pursuant to Rule 13d-1(c), check this box. [X]

Item 4.            Ownership (at December 31, 2005).

           (a).   Amount beneficially owned within the meaning of rule 13d-3::

                  (i) WAM:      1,125,000
                  (ii) WAM GP:  1,125,000

           (b).   Percent of class:

                  (i) WAM:      7.6%
                  (ii) WAM GP:  7.6%

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

           (1)  Sole power to vote or to direct the vote:

                   (i) WAM:     1,125,000
                   (ii) WAM GP: 0

           (2)  Shared power to vote or to direct the vote:

                   (i) WAM:     0
                   (ii) WAM GP: 1,125,000

           (3)  Sole power to dispose or to direct the disposition of:

                   (i) WAM:     2,102,000
                   (ii) WAM GP: 0

           (4) Shared power to dispose or to direct the disposition of:

                   (i) WAM:     0
                   (ii) WAM GP: 1,125,000

Item 5.           Ownership  of Five  Percent  or Less of a  Class:   [ ]

                  Not Applicable




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

                  The  shares  reported  herein  include  the  shares  held by
                  Columbia Acorn Trust (CAT), a  Massachusetts  business trust
                  that is advised by WAM, a Delaware limited partnership.  CAT
                  holds 7.4% shares of the Issuer's shares.

Item 7.           Identification and Classification of Subsidiaries 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

Item 10. Certification:


          (a) The following  certification shall be included if the statement is
              filed pursuant to 240.13d-1(b):


                  By signing  below I certify  that, to the best of my knowledge
                  and belief, the securities referred to above were acquired and
                  are  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.

             Disclaimer

                  In accordance  with Rule 13d-4 of the Securities  Exchange Act
                  of 1934,  each of the persons filing this statement  expressly
                  disclaim the beneficial ownership of the securities covered by
                  this  statement  and the  filing of this  report  shall not be
                  construed  as an  admission  by such persons that they are the
                  beneficial owners of such securities.

                                   SIGNATURES

     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, 2006

                  The undersigned corporation, on the date above written, agrees
                  and  consents  to the  joint  filing  on its  behalf  of  this
                  Schedule 13G in conneciton  with its  beneficial  ownership of
                  the security reported herein.

                                        WAM Acquisition GP, Inc.
                                            for itself and as general partner of
                                            COLUMBIA WANGER ASSET
                                            MANAGEMENT, L.P.



                                        By: /s/ Bruce H. Lauer
                                           -------------------------------------
                                           Bruce H. Lauer
                                           Senior Vice President and Secretary


                                 Exhibit Index

Exhibit 1      Joint Filing Agreement dated as of February 14, 2006 by and among
               Columbia Wanger Asset Management, L.P.; WAM Acquisition GP, Inc.;
               and Columbia Acorn Trust.



                                                                       EXHIBIT 1

                             JOINT FILING AGREEMENT

     The  undersigned  hereby  agree to the joint  filing of the Schedule 13G to
which this Agreement is attached.

                        Dated: February 14, 2006

                                        WAM Acquisition GP, Inc.
                                          for itself and as general partner of
                                          COLUMBIA WANGER ASSET
                                          MANAGEMENT, L.P.



                                        By: /s/ Bruce H. Lauer
                                            -----------------------------------
                                            Senior Vice President and Secretary


                                        COLUMBIA ACORN TRUST


                                       By: /s/ Bruce H. Lauer
                                            -----------------------------------
                                            Senior Vice President and Secretary