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                                                                EXHIBIT 10.16(A)
                               FIRST AMENDMENT TO
               AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT

         THIS FIRST AMENDMENT TO AMENDED AND RESTATED REGISTRATION RIGHTS
AGREEMENT (this "First Amendment"), dated as of May 13, 2002, by and among
Animas Corporation, a Delaware corporation (the "Company"), the Existing Holders
(as such term is defined herein) and persons or entities identified on the
signature pages hereto as the "Second Additional Series C Investors" (each, a
"Second Additional Series C Investor" and collectively, the "Additional Series C
Investors").

         WHEREAS, the Company and certain holders of the Company's capital stock
(the "Existing Holders") have entered into an Amended and Restated Registration
Rights Agreement dated as of October 11, 2001 (together with all joinders
thereto, the "Registration Rights Agreement");

         WHEREAS, concurrently with the execution of this First Amendment, the
Second Additional Series C Investors are acquiring from the Company shares of
the Company's Series C Preferred Stock, $.01 par value per share (the
"Additional Series C Preferred Stock"), pursuant to that certain Amendment to
Series C Convertible Preferred Stock Purchase Agreement dated as of May 13, 2002
(the "Purchase Agreement");

         WHEREAS, as a condition to entering into the Purchase Agreement, the
Second Additional Series C Investors will require the Company and the Existing
Holders to amend the Registration Rights Agreement in order to, among other
things, join the Second Additional Series C Investors as parties thereto;

         WHEREAS, to induce the Second Additional Series C Investors to enter
into the Purchase Agreement and purchase the shares of Series C Stock, the
Company and the Existing Holders desire to amend the Registration Rights
Agreement and to join the Additional Series C Investors as parties thereto as
set forth in full herein; and

         WHEREAS, Section 13(d) of the Registration Rights Agreement provides
that the Registration Rights Agreement may not be amended or modified, and no
provision thereof may be waived, without the written consent of the (i) Company,
(ii) Initial Series B Investors holding at least sixty percent (60%) of the
votes entitled to be cast by the holders of the Series B Conversion Shares owned
by all such Initial Series B Investors, solely with respect to such Series B
Conversion Shares (iii) Initial Series C Investors holding at least sixty
percent (60%) of the votes entitled to be cast by the holders of the Series C
Conversion Shares owned by all such Initial Series C Investors, solely with
respect to such Series C Conversion Shares and (iv) the holders of a majority of
the votes entitled to be cast by the holders of the Registrable Securities then
outstanding, which consent has been obtained;

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         NOW, THEREFORE, in consideration of the agreements and mutual covenants
set forth herein, and for other good and valuable consideration the receipt and
sufficiency of which is hereby acknowledged by the parties, the parties hereto
agree as follows:

         1.       Defined Terms. Capitalized terms used but not otherwise
defined herein shall have the meanings ascribed to such terms in the
Registration Rights Agreement.

         2.       Definition of Series C Investors. The definition of the term
"Series C Investors" set forth in the Registration Rights Agreement is amended
to include the Second Additional Series C Purchasers.

         3.       Definition of Series C Preferred Stock. The definition of the
term "Series C Preferred Stock" set forth in the Registration Rights Agreement
is amended to include the Additional Series C Preferred Stock.

         4.       Definition of Series C Purchase Agreement. The definition of
the term "Series C Purchase Agreement" set forth in the Registration Rights
Agreement is amended to include the Amendment to Series C Convertible Preferred
Stock Purchase Agreement dated as of May 13, 2002 by and among the Company and
the Second Additional Series C Investors.

         5.       Definition of Series A Investor Rights Agreement. The
definition of the term "Series A Investor Rights Agreement" set forth in the
Registration Rights Agreement is amended to mean the Series A Investor Rights
Agreement as amended and in effect on the date hereof.

         6.       Additional Parties. Each of the Additional Series C Purchasers
is hereby joined as a party to the Registration Rights Agreement and is deemed
to be a "Holder" for all purposes under such Registration Rights Agreement and
each of the Additional Series C Purchasers hereby adopts and agrees to be bound
by all of the terms and provisions of, and shall be entitled to all of the
benefits and privileges of a Holder as defined in the Registration Rights
Agreement and subject to the terms and conditions thereof.

         7.       Ratification of Registration Rights Agreement. Except as
expressly amended hereby, all of the terms of the Registration Rights Agreement
shall remain in full force and effect, and are hereby ratified and confirmed.

         8.       Controlling Law. This First Amendment and all questions
relating to its validity, interpretation, performance and enforcement shall be
governed by and construed in accordance with the laws of the Commonwealth of
Pennsylvania, notwithstanding any conflict of laws doctrines of such
Commonwealth or any other jurisdiction to the contrary, and without the aid of
any canon, custom or rule of law requiring construction against the draftsman.

         9.       Execution in Counterparts and via Facsimile. This First
Amendment may be executed via facsimile and in any number of counterparts, each
of which shall be deemed to be an original as against any party whose signature
appears thereon, and all of which together shall constitute one and the same
instrument. This First Amendment shall

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become binding when one or more counterparts hereof, individually or taken
together, shall bear the signatures of: (i) the Company, (ii) each of Additional
Series C Purchasers, (iii) the Initial Series B Investors holding at least 60%
of the votes entitled to be cast by the holders of the Series B Conversion
Shares owned by all such Initial Series B Investors, solely with respect to such
Series B Conversion Shares, (iv) the Initial Series C Investors holding at least
60% of the votes entitled to be cast by the holders of the Series C Conversion
Shares owned by all such Initial Series C Investors, solely with respect to such
Series C Conversion Shares, (v) holders of a majority of the votes entitled to
be cast by the holders of the Registrable Securities then outstanding prior to
sale of the Additional Series C Preferred Stock to the Additional Series C
Purchasers.

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                  IN WITNESS WHEREOF, the parties have executed this First
Amendment to Amended and Restated Registration Rights Agreement on the date
first above written.

COMPANY                         SECOND ADDITIONAL SERIES C INVESTORS

Animas Corporation              PILGRIM BAXTER HYBRID PARTNERS II. L.P.

By: /s/ Richard A. Baron          By:  Pilgrim Baxter Hybrid Partners II General
   ----------------------              Partner, L.P.
                                  Its: General Partner
Name: Richard A. Baron
                                   By: Pilgrim Baxter &. Associates, Ltd.
Its: Vice President, CFO +         Its: General Partner
     Assistant Secty.
                                     By: /s/ Samuel H. Baker
                                         -------------------------------

                                     Name: Samuel H. Baker

                                     Title: Vice President

                                Address: c/o Pilgrim Baxter & Associates
                                         1400 Liberty Ridge Drive
                                         Wayne, PA 19087-5593

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