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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                   -----------
                                   SCHEDULE TO
                                 AMENDMENT NO. 1

                 TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) or 13(e)(1)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                                 EON LABS, INC.
                            (Name of Subject Company)

                                   NOVARTIS AG
                              NOVARTIS CORPORATION
                            ZODNAS ACQUISITION CORP.
                       (Name of Filing Persons--Offerors)

                          COMMON STOCK, PAR VALUE $0.01
                         (Title of Class of Securities)

                                    29412E100
                      (CUSIP Number of Class of Securities)

                                  George Miller
                        Head of Legal and General Affairs
                                   Novartis AG
                                 35 Lichtstrasse
                           CH-4002 Basel, Switzerland
                                 41-61-324-1111
                  (Name, Address and Telephone Number of Person Authorized
             to Receive Notices and Communications on Behalf of Filing Persons)

                                   -Copies to-
                           Andrew R. Brownstein, Esq.
                             Trevor S. Norwitz, Esq.
                         Wachtell, Lipton, Rosen & Katz
                               51 West 52nd Street
                               New York, NY 10019
                                 (212) 403-1000
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                            CALCULATION OF FILING FEE

                   Transaction Valuation Amount of Filing Fee
               -------------------------------------------------
                        $977,098,158*           $115,005*
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*    Estimated  for purposes of  calculating  the amount of the filing fee only.
     The filing  fee is  calculated  based on (i) the total  number of shares of
     common stock,  par value $0.01 of Eon Labs,  Inc.  outstanding as of May 5,
     2005  according  to Eon  Labs,  Inc.'s  Quarterly  Report  filed  with  the
     Commission  on Form 10-Q for the period  ending March 31, 2005 (the "10-Q")
     (excluding (1) 60,000,000  shares of Eon Labs,  Inc.  common stock owned by
     Santo  Holding  (Deutschland)  GmbH which are to be  acquired  outside  the
     United States pursuant to a private agreement and (2) 137,122 shares of Eon
     Labs,  Inc.  common  stock  owned by Hexal  AG which  are to be  indirectly
     acquired  outside the United States  pursuant to a private  agreement)  and
     (ii) the number of options to purchase  shares of common stock of Eon Labs,
     Inc.  outstanding as of March 31, 2005 according to the 10-Q. The amount of
     the filing fee, equals .00011770 multiplied by the transaction value.

[X]  Check  the  box if any  part  of the  fee is  offset  as  provided  by Rule
     0-11(a)(2)  and  identify  the  filing  with which the  offsetting  fee was
     previously  paid.  Identify the previous filing by  registration  statement
     number, or the Form or Schedule and the date of its filing.
       Amount Previously Paid: $115,005         Filing Party:  Novartis Corp.
       Form or Registration No.: Schedule TO    Date Filed:  May 23, 2005

[_]  Check the box if the filing relates  solely to  preliminary  communications
     made before the commencement of a tender offer.

Check the  appropriate  boxes below to designate any  transactions  to which the
statement relates:

[X]  third-party tender offer subject to Rule 14d-1.



[_]  issuer tender offer subject to Rule 13e-4.

[_]  going-private transaction subject to Rule 13e-3.

[_]  amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results
of the tender offer: [_]
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          This Amendment No. 1 amends and supplements the Tender Offer Statement
on Schedule TO (the  "Schedule  TO")  originally  filed with the  Securities and
Exchange  Commission  on May  23,  2005 by  Novartis  AG,  a Swiss  Corporation,
Novartis  Corporation  ("Novartis  US"), a New York  corporation and an indirect
wholly owned subsidiary of Novartis AG, and Zodnas Acquisition Corp. ("Zodnas"),
a Delaware  corporation and an indirect wholly owned  subsidiary of Novartis US.
This  Schedule TO relates to the offer by Zodnas to purchase  any and all of the
outstanding shares of common stock, par value $0.01 per share (the "Shares"), of
Eon Labs, Inc., a Delaware corporation ("Eon"), for $31.00 per Share, net to the
seller in cash,  upon the terms and subject to the  conditions  set forth in the
Offer to  Purchase,  dated May 23,  2005 (the "Offer to  Purchase"),  and in the
related Letter of  Transmittal.  Copies of the Offer to Purchase and the related
Letter of Transmittal  are filed with the Schedule TO as exhibits  (a)(1)(A) and
(a)(1)(B),  respectively.  Capitalized  terms used and not defined  herein shall
have the meanings assigned such terms in the Offer to Purchase and Schedule TO.

ITEMS 1 THROUGH 9 AND 11.

          Items 1 through 9 and 11 of the  Schedule  TO,  which  incorporate  by
reference the information contained in the Offer to Purchase, are hereby amended
and supplemented by adding thereto the following:

          On  May  27,  2005,  the  European   Commission   approved   Novartis'
acquisition of Hexal pursuant to the Hexal Agreement.

          On May 27,  2005,  Novartis  issued  a press  release  announcing  the
regulatory  approval  as  described  above,  a copy of which is filed as Exhibit
(a)(5)(C) hereto and is incorporated herein by reference.

ITEM 12.  EXHIBITS

          Item 12 of the  Schedule  TO is hereby  amended by adding  thereto the
following:

(a)(5)(C) Text of Press Release issued by Novartis dated May 27, 2005.








                                    SIGNATURE

After due 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.

Dated:  May 27, 2005

                                          NOVARTIS AG


                                          By:  /s/ Urs Baerlocher            
                                               ------------------------------
                                               Name:  Urs Baerlocher
                                               Title: Authorized Signatory


                                          By:  /s/ Joerg Walther             
                                               ------------------------------
                                               Name:  Joerg Walther
                                               Title: Authorized Signatory


                                          NOVARTIS CORPORATION


                                          By:  /s/ Martin Henrich            
                                               ------------------------------
                                               Name:  Martin Henrich
                                               Title: Executive Vice President


                                          ZODNAS ACQUISITION CORP.


                                          By:  /s/ Wayne P. Merkelson        
                                               ------------------------------
                                               Name:  Wayne P. Merkelson
                                               Title: Vice President







                                  EXHIBIT INDEX



*(a)(1)(A)      Offer to Purchase, dated May 23, 2005.

*(a)(1)(B)      Form of Letter of Transmittal.

*(a)(1)(C)      Form of Notice of Guaranteed Delivery.

*(a)(1)(D)      Form of Letter to Brokers, Dealers, Commercial Banks, 
                Trust Companies and Other Nominees.

*(a)(1)(E)      Form of Letter to Clients for use by Brokers, Dealers,
                Commercial Banks, Trust Companies and Other Nominees.

*(a)(1)(F)      Guidelines for Certification of Taxpayer Identification Number
                (TIN) on Substitute Form W-9.

(a)(2)          Not applicable.

(a)(3)          Not applicable.

(a)(4)          Not applicable.

*(a)(5)(A)      Text of Press Release issued by Novartis dated February 21,
                2005,incorporated in this Schedule TO by reference to the 
                Schedule TO filed by Novartis AG, Novartis US and Zodnas on
                February 22, 2005.

*(a)(5)(B)      Form of Summary Advertisement published in The Wall Street
                Journal on May 23, 2005.

(a)(5)(C)       Text of Press Release issued by Novartis dated May 27, 2005.

*(a)(6)(A)      Complaint titled Ellen Wiehl v. Eon Labs, Inc. et al., filed on
                February 22, 2005, in the Chancery Court of the State of 
                Delaware, County of New Castle.

*(a)(6)(B)      Complaint titled Paulena Partners LLC v. Eon Labs, Inc. et al.,
                filed on February 22, 2005, in the Chancery Court of the State 
                of Delaware, County of New Castle.

*(a)(6)(C)      Complaint titled Robert Kemp, IRRA v. Eon Labs, Inc. et al.,
                filed on February 22, 2005, in the Chancery Court of the State 
                of Delaware, County of New Castle.

*(a)(6)(D)      Complaint titled Peter J. Calcagno v. Eon Labs, Inc. et al., 
                filed on February 23, 2005, in the Chancery Court of the State 
                of Delaware, County of New Castle.





*(a)(6)(E)      Complaint titled Christopher Pizzo v. Novartis AG et al., filed 
                on February 23, 2005, in the Supreme Court of the State of New 
                York, County of New York.

*(a)(6)(F)      Complaint titled Erste Sparinvest Kapitalanlagegesellschaft MBH
                v. Eon Labs, Inc. et al., filed on March 1, 2005, in the 
                Chancery Court of the State of Delaware, County of New Castle.

*(a)(6)(G)      Complaint titled Merl Huntsinger v. Eon Labs, Inc. et al., filed
                on March 1, 2005, in the Chancery Court of the State of
                Delaware, County of New Castle.

*(a)(6)(H)      Complaint titled Jason Hung v. Eon Labs, Inc. et al., filed on
                March 3, 2005, in the Chancery Court of the State of Delaware, 
                County of New Castle.

(b)             None.

*(d)(1)         Agreement and Plan of Merger, dated as of February 20, 2005, by
                and among Novartis US, Zodnas, Eon and, for purposes of Section 
                12 thereof only, Novartis AG, incorporated in this Schedule TO 
                by reference to Exhibit 2.2 to the Schedule 13D filed by 
                Novartis US, Novartis AG and Zodnas on March 2, 2005.

*(d)(2)         Agreement for Purchase and Sale of Stock, dated as of February 
                20, 2005, by and between Novartis US, Santo and, for purposes of
                Section 10.12 thereof only, Novartis AG, incorporated in this 
                Schedule TO by reference to Exhibit 2.1 to the Schedule 13D 
                filed by Novartis US, Novartis AG and Zodnas on March 2,2005.

*(d)(3)         Confidentiality Agreement, by and between Novartis US and Eon, 
                dated as of February 11, 2005, incorporated in this Schedule TO
                by reference to Exhibit 2.3 to the Schedule 13D filed by 
                Novartis US, Novartis AG and Zodnas on March 2, 2005.

(g)             None.

(h)             Not applicable.

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* Previously filed.