Exhibit 10.60

[*CONFIDENTIAL TREATMENT HAS BEEN REQUESTED AS TO CERTAIN PORTIONS OF THIS
DOCUMENT. EACH SUCH PORTION, WHICH HAS BEEN OMITTED HEREIN AND REPLACED WITH AN
ASTERISK ****, HAS BEEN FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION.]

AMENDMENT NO. 2 TO EXCLUSIVE CLINICAL STUDY AND DATA LICENSE

AGREEMENT BETWEEN GENZYME CORPORATION AND VIROPHARMA

INCORPORATED

This Amendment No. 2 (the “Amendment”) to the Exclusive Clinical Study and Data
License Agreement dated June 12, 2009 (the “Agreement”) by and between Genzyme
Corporation (“Genzyme”) and ViroPharma Incorporated (“ViroPharma”), as amended
on October 21, 2009, is effective as of April 5, 2010 (“Amendment Effective
Date”).

WHEREAS, Genzyme and ViroPharma are parties to the Agreement, pursuant to which
Genzyme granted ViroPharma a license to certain clinical studies and data
related to Genzyme’s proprietary product, tolevamer;

WHEREAS, Genzyme and ViroPharma now wish to amend certain provisions of the
Agreement to allow Genzyme to receive a royalty in the event that ViroPharma, or
its distributor, launches an authorized generic version of the Product;

NOW, THEREFORE, in consideration of the promises and agreements set forth
herein, and for other good and valuable consideration, the parties hereby agree
as follows:

 

1. Capitalized terms not defined herein shall have the meaning ascribed to such
terms in the Agreement.

 

2. The following language shall be added as Section 4(b)(4) of the Agreement:

In the event that ViroPharma, either alone or pursuant to an agreement with an
authorized generic distributor (“AG Distributor”), distributes an authorized
generic version of the Product (“AG Product”) during the Royalty Term,
ViroPharma will pay Genzyme a royalty on all revenue (****) from sales of the AG
Product in the Territory received by ViroPharma (either directly or from an AG
Distributor) (the “AG Royalty”) as follows:

 

Year Following Initiation Date

   AG Royalty Rate  

1

     8 % 

2

     8 % 

3

     12.8 % 

--------------------------------------------------------------------------------

[*CONFIDENTIAL TREATMENT HAS BEEN REQUESTED AS TO CERTAIN PORTIONS OF THIS
DOCUMENT. EACH SUCH PORTION, WHICH HAS BEEN OMITTED HEREIN AND REPLACED WITH AN
ASTERISK ****, HAS BEEN FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE
COMMISSION.]

 

If, in addition to the AG Product, **** Third Parties are selling an Other
Vancomycin Product to a wholesaler, distributor, consumer or any other Third
Party, the AG Royalty will be as follows during the Royalty Term:

 

Year Following Initiation Date

   AG Royalty Rate  

1

     7.5 % 

2

     7.5 % 

3

     12 % 

If, in addition to the AG Product, **** Third Parties are selling an Other
Vancomycin Product to a wholesaler, distributor, consumer or any other Third
Party, the AG Royalty will be as follows during the Royalty Term:

 

Year Following Initiation Date

   AG Royalty Rate  

1

     7 % 

2

     7 % 

3

     11.2 % 

The AG Royalty shall be in addition to the Royalties paid to Genzyme under
Section 4(b)(1). ViroPharma shall pay Genzyme the AG Royalty in accordance with
the terms of the Agreement and ViroPharma shall include the revenues received by
ViroPharma from the AG Product, and the calculation of the AG Royalty, in the
Sales Reports provided in accordance with Section 4(b)(2).

Except as expressly modified hereby, the terms of the Agreement remain in full
force and effect and shall govern and apply to all matters contemplated by this
Amendment.

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
by their duly authorized representatives as of the Amendment Effective Date.

 

VIROPHARMA INCORPORATED     GENZYME CORPORATION By:   /s/ Vincent J. Milano    
By:   /s/ John P. Butler Name:   Vincent J. Milano     Name:   John P. Butler
Title:   President & CEO     Title:   President, Cardiometabolic & Renal Date:  
April 12, 2010     Date:   April 2, 2010