<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>sc13g_080404-biomarin.txt
<DESCRIPTION>SCHEDULE 13G
<TEXT>
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G
                    Under the Securities Exchange Act of 1934

                          Biomarin Pharmaceutical Inc.
                                (Name of Issuer)

                                  Common Stock
                         (Title of Class of Securities)

                                    09061G101
                                 (CUSIP Number)

                                  June 1, 2004

             (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)

[ ] 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).


<PAGE>


                               CUSIP No. 09061G101


          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
Number of
Shares           6.  Shared Voting Power: 2,538,900
Beneficially
Owned by         7.  Sole Dispositive Power:  0
Each Reporting
Person With      8.  Shared Dispositive Power: 2,538,900

          9.   Aggregate Amount Beneficially Owned by Each Reporting Person
               2,538,900

          10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares
               (See Instructions)

          11.  Percent of Class Represented by Amount in Row (9) 3.94%

          12.  Type of Reporting Person (See Instructions) IA


<PAGE>


                               CUSIP No. 09061G101


          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: 693,300
Beneficially
Owned by         7.  Sole Dispositive Power:  0
Each Reporting
Person With      8.  Shared Dispositive Power: 693,300

          9.   Aggregate Amount Beneficially Owned by Each Reporting Person
               693,300

          10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares
               (See Instructions)

          11.  Percent of Class Represented by Amount in Row (9) 1.08%

          12.  Type of Reporting Person (See Instructions) IA


<PAGE>


                               CUSIP No. 09061G101


          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: 3,232,200
Beneficially
Owned by         7.  Sole Dispositive Power:  0
Each Reporting
Person With      8.  Shared Dispositive Power: 3,232,200

          9.   Aggregate Amount Beneficially Owned by Each Reporting Person:
               3,232,200

          10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares
               (See Instructions)

          11.  Percent of Class Represented by Amount in Row (9) 5.02%

          12.  Type of Reporting Person (See Instructions) HC


<PAGE>


Item 1. (a)  Issuer: Biomarin Pharmaceutical Inc.

          1.   Address:
               371 Bel Marin Keys Boulevard, Suite 210
               Novato, California 94949

Item 2. (a)  Name of Person Filing:
             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: 09061G101

Item 3. OrbiMed Advisors LLC and OrbiMed Capital LLC are investment advisors in
accordance with ss.240.13d-1(b)(1)(ii)(E). Samuel D. Isaly is a control person
in accordance with ss.240.13d-1(b)(1)(ii)(G).

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

         Not Applicable


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

                Reporting persons are holding 5.02% (3.94% in the case of
         OrbiMed Advisors LLC and 1.08% in the case of OrbiMed Capital LLC) 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 proceeds from
         sale of, such securities. No one such other person's interest in the
         securities whose ownership is reported here relates to more than five
         percent of the class.

                OrbiMed Advisors LLC and OrbiMed Capital LLC hold shares on
         behalf of Caduceus Capital Trust (765,000 shares), Caduceus Capital II,
         L.P. (443,400 shares), UBS Eucalyptus Fund, Ltd. (781,000 shares),
         PaineWebber Eucalyptus Fund, Ltd. (97,000 shares), HFR SHC Aggressive
         Fund (110,000 shares), Knightsbridge Post Venture IV L.P. (103,000
         shares), Knightsbridge Integrated Holdings, V, LP (83,000 shares),
         Knightsbridge Netherlands II, L.P. (28,300 shares), Knightsbridge
         Integrated Holdings IV Post Venture, LP (48,400 shares), Knightsbridge
         Post Venture III, LP (46,700 shares), Knightsbridge Netherlands I LP
         (35,900 shares), Knightsbridge Netherlands III LP (16,700 shares),
         Knightsbridge Integrated Holdings II Limited (53,000 shares),
         Knightsbridge Venture Capital IV, L.P. (19,800 shares), Knightsbridge
         Venture Capital III LP (15,400), Finsbury Worldwide Pharmaceutical
         Trust (565,000 shares), Topanga XIII Inc. (18,300 shares) and, Caduceus
         Capital III, L.P. (2,300 shares).


<PAGE>

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

Item 10. Certification

         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.


<PAGE>


                                    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: August 3, 2004
                                       OrbiMed Advisors LLC

                                       By: /s/ Samuel D. Isaly
                                       --------------------------
                                       Name:  Samuel D. Isaly
                                       Title: President

                                       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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