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

                                 SCHEDULE 13G/A
                    Under the Securities Exchange Act of 1934
                                 Amendment No.1

                           Ligand Pharmaceuticals Inc.
                                (Name of Issuer)

                                  Common Stock
                         (Title of Class of Securities)

                                    53220K207
                                 (CUSIP Number)

                                December 31, 2003

             (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).





                               CUSIP No. 53220K207

     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: 7,209,422
Beneficially
Owned by         7.  Sole Dispositive Power:  0
Each Reporting
Person With      8.  Shared Dispositive Power: 7,209,422

     9.   Aggregate Amount Beneficially Owned by Each Reporting Person
          7,209,422

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

     11.  Percent of Class Represented by Amount in Row (9) 9.71%

     12.  Type of Reporting Person (See Instructions) IA








                               CUSIP No. 53220K207



     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: 7,209,422
Beneficially
Owned by         7.  Sole Dispositive Power:  0
Each Reporting
Person With      8.  Shared Dispositive Power: 7,209,422

     9.   Aggregate Amount Beneficially Owned by Each Reporting Person 7,209,422

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

     11.  Percent of Class Represented by Amount in Row (9) 9.71%

     12.  Type of Reporting Person (See Instructions) IA







                               CUSIP No. 53220K207


     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: 7,209,422
Beneficially
Owned by         7.  Sole Dispositive Power:  0
Each Reporting
Person With      8.  Shared Dispositive Power: 7,209,422

     9.   Aggregate Amount Beneficially Owned by Each Reporting Person:
          7,209,422

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

     11.  Percent of Class Represented by Amount in Row (9) 9.71%

     12.  Type of Reporting Person (See Instructions) HC







Item 1. (a) Issuer: Ligand Pharmaceuticals Inc.

          1.   Address:
               10275 Science Center Drive
               San Diego, CA 92121-1117


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: 53220K207

Item 3. OrbiMed Advisors Inc. and OrbiMed Advisors LLC are investment
advisors in accordance withss.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 9.71% 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 sole of, such securities.








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.











                                    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 17, 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







 EX-1.1 OTHERDOC
          2
          0002.txt
                             JOINT FILING AGREEMENT
Exhibit 1.1
----------

                             JOINT FILING AGREEMENT

The undersigned hereby agree that the Statement on this Schedule 13G/A, dated
February 17, 2004, (the "Schedule 13G/A"), with respect to the Common Stock,
par value $0.001 per share, of Ligand Pharmaceuticals Inc. is filed on behalf of
each of us pursuant to and in accordance with the provisions of Rule 13d-1(k)
under the Securities and Exchange Act of 1934, as amended, and that this
Agreement shall be included as an Exhibit to this Schedule 13G/A. Each of the
undersigned agrees to be responsible for the timely filing of the Schedule
13G/A, and for the completeness and accuracy of the information concerning
itself contained therein. This Agreement may be executed in any number of
counterparts, all of which taken together shall constitute one and the same
instrument.

         IN WITNESS WHEREOF, the undersigned have executed this Agreement as of
the 17th day of February 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







EX-2.1 OTHERDOC
Statement of Control Person

Exhibit 2.1
----------

                           Statement of Control Person


The Statement on this Schedule 13G/A dated February 17, 2004 with respect to
the common stock $0.001 par value per share of Ligand Pharmaceuticals Inc. is
filed by Samuel D. Isaly in accordance with the provisions of Rule 13d-1(b) and
Rule 13d-1(k), respectively, as a control person (HC) of OrbiMed Advisors LLC
and OrbiMed Capital LLC.

OrbiMed Advisors LLC and OrbiMed Capital LLC file this statement on Schedule
13G/A in accordance with the provisions of Rule 13d-1(b) and Rule 13d-1(k),
respectively, as investment advisors (IA).