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

                                  SCHEDULE 13G
                                 (Rule 13d-102)


      INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d
                -1(b), (c) AND (d) AND AMENDMENTS THERETO FILED
                            PURSUANT TO RULE 13d-2(b)
                              (Amendment No. 20)(1)

                            Advanced Magnetics, Inc.
                                (Name of Issuer)

                                  Common Stock
                         (Title of Class of Securities)

                                   00753P 10 3
                                 (CUSIP Number)

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

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



         Rule 13d-1(b)
     ----

         Rule 13d-1(c)
     ----

      x  Rule 13d-1(d)
     ----





--------------------
(1) 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 on 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 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).







1           Name of Reporting Person/I.R.S. Identification Nos. of Above Persons
            (Entities Only)


            Jerome Goldstein


2           Check the Appropriate Box If a Member of a Group            (a) |_|
            (See Instructions)                                          (b) |_|


3           SEC Use Only


4           Citizenship or Place of Organization


            United States of America

                          5         Sole Voting Power
       Number of
         Shares
      Beneficially                  164,375
        Owned by
          Each
       Reporting          6         Shared Voting Power
         Person
          With
                                    788,900

                          7         Sole Dispositive Power


                                    164,375

                          8         Shared Dispositive Power


                                    788,900

9           Aggregate Amount Beneficially Owned by Each Reporting Person


            953,275

10          Check If the Aggregate Amount in Row (9) Excludes Certain Shares   X
            (See Instructions)


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


            9.6%

12          Type of Reporting Person (See Instructions)


            IN

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Item 1.

     (a) Name of issuer:

           Advanced Magnetics, Inc.

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

           61 Mooney Street
           Cambridge, MA 02138

Item 2.

     (a) Name of Person Filing:

           Jerome Goldstein

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

           c/o Advanced Magnetics, Inc.
                 61 Mooney Street
                 Cambridge, MA 02138

     (c)  Citizenship:

           United States of America

     (d) Title of Class of Securities:

           Common Stock, $.01 par value per share

     (e) CUSIP Number:

            00753P 10 3

Item 3.  If the Statement is being filed pursuant to ss.ss.240.13d-1(b)
         or 240.13d-2(b) or (c), check whether the filing person 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 inn 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) / / An investment adviser in accordance with ss.240.13d-l(b)(1)(ii)(E);

     (f) / / An employee benefit plan or endowment fund in accordance with
             ss.240.13d-1(b)(1)(ii)(F);

     (g) / / A parent holding company or control person in accordance with
             ss.240.13d-1(b)(1)(ii)(G);

                                      -3-


     (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 ss.240.13d-1(b)(1)(ii)(J).


Item 4.  Ownership.

Provide the following information regarding the aggregate number and percentage
of the class of securities of the issuer identified in Item 1.

     (a) Amount beneficially owned: 953,275. This amount consists of: (a) 38,900
shares held by the Kaplan Goldstein Family Foundation, a charitable foundation
whose trustees are Jerome Goldstein, Marlene Kaplan Goldstein, and Mr. and Mrs.
Goldstein's adult children, each of whom share voting and investment power; (b)
375,000 shares held in Mr. Goldstein's grantor retained annuity trusts for which
Mr. Goldstein's spouse is one of the trustees and 375,000 shares held in Mr.
Goldstein's spouse's grantor retained annuity trusts for which Mr. Goldstein is
one of the trustees and has shared voting and investment power; and (c) 18,672
shares issuable to Mr. Goldstein pursuant to options currently exercisable or
exercisable within 60 days of December 31, 2005. This amount does not include
156,087 shares directly held by Mr. Goldstein's spouse.

     (b) Percent of class:  9.6% (based on  9,910,229  shares of Common Stock
         reported by the Company's transfer agent as outstanding at the close
         of  business on  December  31,  2005 in  addition  to 18,672  shares
         issuable to Mr. Goldstein pursuant to options  exercisable within 60
         days of December 31, 2005).

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

         (i)   Sole power to vote or direct the vote:                  164,375

         (ii)  Shared power to vote or direct the vote:                 788,900

         (iii) Sole power to dispose or to direct the disposition of:   164,375

         (iv)  Shared power to dispose or to direct the disposition of: 788,900

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 had ceased to be the beneficial owner of more than
five percent of the class of securities, check the following [__].

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 or Control
         Person.

     Not applicable.

                                      -4-


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 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.

                                                   February 8, 2006
                                          ------------------------------------
                                                        (Date)


                                                 /s/ Jerome Goldstein
                                          ------------------------------------
                                                     (Signature)


                                          Jerome Goldstein, Chairman of the
                                          Board of Directors, Chief Executive
                                          Officer and Treasurer
                                          ------------------------------------
                                                   (Name/Title)



Attention. Intentional misstatements or omissions of fact constitute Federal
criminal violations (See 18 U.S.C. 1001)



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