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                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D. C. 20549


                                 ____________

                                   FORM 8-K
                                 ____________


                                CURRENT REPORT
                    PURSUANT TO SECTION 13 OR 15(d) OF THE
                        SECURITIES EXCHANGE ACT OF 1934


                              Insmed Incorporated
                              -------------------
            (Exact name of registrant as specified in its charter)



          Virginia                     0-30739               54-1972729
          --------                     -------               ----------
   (State of incorporation      (Commission File No.)     (IRS employer
      or organization)                                    identification no.)



                              800 East Leigh Street
                            Richmond, Virginia 23219
                    (Address of principal executive offices)

                                 (804)-828-6893
              (Registrant's telephone number, including area code)




                           May 16, 2001 Date of Report
                       (Date of earliest event reported):

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Item 5.        Other Events
               ------------

     On May 16, 2001 (the "Rights Authorization Date"), the Board of Directors
of Insmed Incorporated, a corporation organized under the laws of the
Commonwealth of Virginia (the "Company"), approved a Rights Agreement, dated as
of and to be effective as of May 16, 2001 (the "Rights Agreement"), between the
Company and First Union National Bank, as Rights Agent, having the principal
terms summarized below. In accordance with the Rights Agreement, the Board also
declared a dividend distribution of one right ("Right") for each outstanding
share of common stock of the Company (the "Common Stock") to shareholders of
record at the close of business on June 1, 2001 (the "Record Date").

     Each Right entitles the holder to purchase from the Company one one-
thousandth (1/1000/th/) of a share of a series of the Company's preferred stock
designated as Series A Junior Participating Preferred Stock ("Preferred Stock")
at a price of $35 per one one-thousandth (1/1000/th/) of a share, subject to
adjustment (the "Purchase Price"). Each one one-thousandth of a share of
Preferred Stock is structured to be the equivalent of one share of Common Stock
of the Company ("Common Stock"). Shareholders will receive one Right per share
of Common Stock held of record at the close of business on the Record Date.

     Initially, the Rights will be attached to all Common Stock certificates
representing shares then outstanding, and no separate Rights Certificates will
be distributed. Subject to certain exceptions specified in the Rights Agreement,
the Rights will separate from the Common Stock and a distribution of the Rights
Certificates will occur ("Distribution Date") upon the earlier of (i) the Close
of Business on the tenth Business Day following a public announcement that a
person or group of affiliated or associated persons (an "Acquiring Person") has
acquired, or obtained the right to acquire, beneficial ownership of 15% or more
of the outstanding shares of Common Stock (the "Stock Acquisition Date"), other
than as a result of repurchases of stock by the Company or through inadvertance
by certain institutional shareholders or (ii) the Close of Business on the tenth
Business Day (or such later date as the Board shall determine) following the
commencement of a tender offer or exchange offer that would result in a person
or group becoming an Acquiring Person. Until the Distribution Date, (i) the
Rights will be evidenced by the Common Stock certificates and will be
transferred with and only with such Common Stock certificates, (ii) new Common
Stock certificates issued after the Record Date will contain a legend
incorporating the Rights Agreement by reference and (iii) the surrender for
transfer of any certificates for Common Stock outstanding will also constitute
the transfer of the Rights associated with the Common Stock represented by such
certificate. Pursuant to the Rights Agreement, the Company reserves the right to
require prior to the occurrence of a Triggering Event (as defined below) that,
upon any exercise of Rights, a number of Rights be exercised so that only whole
shares of Preferred Stock will be issued.

     The Rights are not exercisable until the Distribution Date and will expire
at 5:00 P.M. (Richmond, Virginia time) on May 16, 2011 (the "Expiration Date"),
unless such date is extended or the Rights are earlier redeemed or exchanged by
the Company as described below.

     As soon as practicable after the Distribution Date, Rights Certificates
will be mailed to holders of record of the Common Stock as of the close of
business on the Distribution Date and, thereafter, the separate Right
Certificates alone will represent the Rights. Except as otherwise determined by
the Board of Directors of the Company or as provided in the Rights Agreement,
only shares of Common Stock issued prior to the Distribution Date will be issued
with Rights.

     In the event that a Person becomes an Acquiring Person, each holder of a
Right will thereafter have the right to receive, upon exercise, Common Stock
(or, in certain circumstances,


cash, property or other securities of the Company) having a value equal to two
times the purchase price of the Right. Notwithstanding any of the foregoing,
following the occurrence of the event set forth in this paragraph, all Rights
that are, or (under certain circumstances specified in the Rights Agreement)
were, beneficially owned by any Acquiring Person will be null and void. However,
Rights are not exercisable following the occurrence of the event set forth above
until such time as the Rights are no longer redeemable by the Company as set
forth below.

     For example, at an exercise price of $35 per Right, each Right not owned by
an Acquiring Person (or by certain related parties) following an event set forth
in the preceding paragraph would entitle its holder to purchase $70 worth of
Common Stock (or other consideration, as noted above) for $35. Assuming that the
Common Stock had a per share value of $10 at such time, the holder of each valid
Right would be entitled to purchase seven shares of Common Stock for an
aggregate of $35.

     In the event that, on or at any time after a Stock Acquisition Date, the
Company (i) engages in a merger, statutory share exchange, or other business
combination transaction (in which the Company is not the surviving corporation),
(ii) the Company engages in a merger, statutory share exchange, or other
business combination transaction in which the Company is the surviving
corporation and any shares of the Company's Common Stock are changed into or
exchanged for other securities or assets or (iii) 50% or more of the assets,
cash flow or earning power of the Company and its subsidiaries (taken as a
whole) are sold or transferred, each holder of a Right (except as noted below)
shall thereafter have the right to receive, upon the exercise thereof at the
then current purchase price of the Right, that number of shares of common stock
of the acquiring company which at the time of such transaction would have a
market value (determined as provided in the Rights Agreement) of two times the
purchase price of the Right. The events set forth in this paragraph and in the
second preceding paragraph are referred to as the "Triggering Events."

     Upon the occurrence of a Triggering Event that entitles Rights holders to
purchase securities or assets of the Company, Rights that are or were owned by
the Acquiring Person, or any affiliate or associate of such Acquiring Person, on
or after such Acquiring Person's Stock Acquisition Date shall be null and void
and shall not thereafter be exercised by any person (including subsequent
transferees). Upon the occurrence of a Triggering Event that entitles Rights
holders to purchase common stock of a third party, or upon the authorization of
an Exchange (as defined below), Rights that are or were owned by any Acquiring
Person or any affiliate or associate of any Acquiring Person on or after such
Acquiring Person's Stock Acquisition Date shall be null and void and shall not
thereafter be exercised by any person (including subsequent transferees).

     The Purchase Price payable, and the number of shares of Preferred Stock,
Common Stock or other securities or property issuable upon exercise of the
Rights are subject to adjustment from time to time to prevent dilution.

     At any time (including a time after any person becomes an Acquiring
Person), the Company may exchange all or part of the Rights (except as set forth
below) for shares of Common Stock (an "Exchange") at an exchange ratio of one
share per Right, as appropriately adjusted to reflect any stock split or similar
transaction.

     At any time prior to the earlier of (i) ten days following the Stock
Acquisition Date, and (ii) the Expiration Date, or said later date as the Board
may set, the Company may redeem the Rights in whole, but not in part, at a price
of $.01 per Right (the "Redemption Price").

                                      -2-

Immediately upon the action of the Board ordering redemption of the Rights, the
Rights will terminate and the only right of the holders of Rights will be to
receive the Redemption Price.

      Until a Right is exercised, the holder thereof, as such, will have no
rights as a shareholder of the Company, including, without limitation, the right
to vote or to receive dividends. While the distribution of the Rights will not
be taxable to shareholders or to the Company, shareholders may, depending upon
the circumstances, recognize taxable income in the event that the Rights become
exercisable for Common Stock (or other consideration) of the Company or for
common stock of the acquiring company or in the event of the redemption of the
Rights, as set forth above.

      Other than certain provisions relating to the principal economic terms of
the Rights, any of the provisions of the Rights Agreement may be amended by the
Board prior to the Distribution Date. After the Distribution Date, the
provisions of the Rights Agreement may be amended by the Board in order to cure
any ambiguity, to make certain other changes that do not adversely affect the
interests of holders of Rights (excluding the interests of any Acquiring
Person), or to shorten or lengthen any time period under the Rights Agreement;
provided, however, no amendment to adjust the time period governing redemption
may be made at such time as the Rights are not redeemable.

      The Rights Agreement (which includes as (i) Exhibit A the form of Articles
of Amendment to the Company's Articles of Incorporation, as amended, (ii)
Exhibit B the form of Rights Certificate, and (iii) Exhibit C the Summary of the
Rights to Purchase Preferred Stock) is attached to this Current Report on Form
8-K as an exhibit and is incorporated herein by reference. The Press Release,
dated May 16, 2001, announcing the adoption of the Rights Agreement by the Board
of Directors is attached to this Current Report on Form 8-K as an exhibit and is
incorporated herein by reference. The foregoing description of the Rights is
qualified in its entirety by reference to the Rights Agreement and its exhibits.

Item 7.      Financial Statements, Pro Forma Financial Information and Exhibits.

(c) Exhibits:

4.4   Rights Agreement, dated as of May 16, 2001, by and between the Company and
      First Union National Bank, as Rights Agent (which includes as (i) Exhibit
      A the form of Articles of Amendment to the Company's Articles of
      Incorporation, as amended, (ii) Exhibit B the form of Rights Certificate,
      and (iii) Exhibit C the Summary of the Rights to Purchase Preferred Stock)
      (filed as Exhibit 4.4 to the Registration Statement on Form 8-A, as filed
      with the Securities and Exchange Commission on May 17, 2001, and
      incorporated herein by reference).

99.2  Press Release of Insmed Incorporated, dated May 17, 2001

                                      -3-


                                   SIGNATURE

      Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereto duly authorized.

                            INSMED INCORPORATED
                                (Registrant)



                            By:  /s/ Geoffrey Allan, Ph.D.
                                 -----------------------------------------------
                                 Geoffrey Allan, Ph.D.
                                 Chairman of the Board, President and Chief
                                 Executive Officer


Dated: May 17, 2001

                                      -4-


                                 EXHIBIT INDEX



Exhibit No.        Description
----------------   -------------------------------------------------------

     4.4           Rights Agreement, dated as of May 16, 2001, by and between
                   the Company and First Union National Bank, as Rights Agent
                   (which includes as (i) Exhibit A the form of Articles of
                   Amendment to the Company's Articles of Incorporation, as
                   amended, (ii) Exhibit B the form of Rights Certificate, and
                   (iii) Exhibit C the Summary of the Rights to Purchase
                   Preferred Stock) (filed as Exhibit 4.4 to the Registration
                   Statement on Form 8-A, as filed with the Securities and
                   Exchange Commission on May 17, 2001, and incorporated herein
                   by reference).

    99.2           Press Release of Insmed Incorporated, dated May 17, 2001.