EXHIBIT 10.1

Portions of this Exhibit have been omitted
pursuant to a request for confidential treatment.
The omitted portions are marked ***** and have
been filed separately with the Commission

 AMENDMENT NO. 2 TO THE COLLABORATION AND SUPPLY AGREEMENT BETWEEN
SOLIGENIX, INC., ENTERON PHARMACEUTICALS, INC. and SIGMA-TAU PHARMACEUTICALS,
INC.
 
This Amendment no.2 ("Amendment") is entered into effective as of the 20th day
of December, 2012 (the “Amendment Effective Date”) by and between, on the one
hand, Soligenix, Inc. (formerly known as DOR BioPharma, Inc.), a Delaware
corporation (“SOLIGENIX”), Enteron Pharmaceuticals, Inc., a Delaware corporation
a wholly-owned subsidiary of Soligenix (“Enteron”, and together with Soligenix,
the “Company”) and on the other hand, Sigma-Tau Pharmaceuticals, Inc.
(“Sigma-Tau”).

WHEREAS, Sigma-Tau and Company entered into a “Collaboration and Supply
Agreement” dated as of February 11, 2009 and as amended on July 27, 2011
(collectively the "Collaboration Agreement");

WHEREAS, Company has requested that Sigma-Tau consider giving back all of its
rights on the PRODUCT to Company or to a third party designed by Company; and

WHEREAS, Sigma-Tau is willing to return all of Company’s rights under the terms
and conditions hereof;

NOW, THEREFORE, in consideration of the mutual promises of the parties contained
in this Amendment, and for other good and valuable consideration, the parties
hereby agree as follows:

1.  
 
2.  
All capitalized terms not defined herein shall have the meanings described to
them in the Collaboration Agreement.
 
Company acknowledges and agrees that Sigma-Tau is hereby released from any and
all of its obligations stemming from the Collaboration Agreement. Company
further acknowledges and agrees that no compensation, reimbursement or payment
whatsoever
is  or  will  be  due  from  Sigma-Tau  under  and/or  in  connection  with  the
Collaboration Agreement and this Amendment no.2. In consideration of Sigma-Tau
being released from any such obligations, and of the other amounts set forth in
Section 3 herein, Sigma-Tau hereby assigns and transfers all of its rights under
the Collaboration Agreement to Company.

 
 
 

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(The information below marked by ***** has been omitted by a request for
confidential treatment.
The omitted portion has been separately filed with the Commission.)
 
3.  
Company undertakes to pay Sigma-Tau and/or have the Potential Partner, as
defined hereinafter, pay to Sigma-Tau the following amounts:

 
a)  
***** upon the first approval of an NDA for the PRODUCT in the United States;
and

 
b)  
***** at the end of the first year following the COMMERCIALIZATION of the first
PRODUCT in the United States; and

 
c)  
***** upon the first approval of an NDA for the PRODUCT in the European Union;
and

 
d)  
***** upon the first approval of an NDA for the PRODUCT in any other country of
the world; and

 
e)  
A royalty amount equal to 3.0% (three percent) of all Net Sales (as such term is
defined in the Collaboration Agreement) of the PRODUCT made directly by Company,
any third party potential partner (the “Potential Partner”) and/or their
AFFILIATES in each relevant country of the TERRITORY. Such amount shall be paid
on a product-by-product and a country-by country basis, for ten (10) years from
the FIRST COMMERCIAL SALE of the PRODUCT in each relevant country of the
TERRITORY or until the expiration of any applicable PATENT RIGHTS, whichever of
these two terms is longer; and

 
f)  
An amount equal to 15% (fifteen percent) of all upfront payments, milestone
payments and other consideration whatsoever (exclusive of equity payments)
received by Company and/or the Potential Partner from any Company’s and/or
Potential Partner’s licensees, distributors and agents (including without
limitation their respective AFFILIATES and such AFFILIATES’ distributors and
agents) for the PRODUCT in each relevant country of the TERRITORY. Such amount
shall be paid on a product-by-product and a country-by country basis, for ten
(10) years from the FIRST COMMERCIAL SALE of the PRODUCT in each relevant
country of the TERRITORY or until the expiration of any applicable PATENT
RIGHTS, whichever of these two terms is longer. In the event that the royalties
paid to Company and/or the Potential Partner and/or their respective AFFILIATES
are incorporated in the cost of goods invoiced, the parties agree that, once
deducted the documented, direct manufacturing costs of the PRODUCT actually
borne by Company and/or the Potential Partner and/or their AFFILIATES, royalties
will also be subject to the above payment obligation at the rate set out above.
Company agrees to consult with Sigma-Tau and to have the Potential Partner
consult with Sigma-Tau prior to the entering into any transaction with third
parties implementing the structure referred to in this Section 3(f).

 
 
 

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In addition to the foregoing, Sigma-Tau will receive once each quarter a written
report for the calendar quarter showing the Net Sales in unit and value by the
Company and/or the Potential Partner and/or their AFFILIATES, distributors or
agents in each country during the reporting period and the amounts payable
hereunder. Reports and payments shall be due within thirty (30) days following
the close of each calendar quarter.
 
All other terms and conditions of this Amendment, including without limitation
the provisions concerning governing law, jurisdiction, confidentiality,
assignment and severability, shall conform to the extent possible to the
corresponding clauses in the  Collaboration Agreement; provided that with
respect to the assignment provision, Sigma-Tau shall agree to Company’s
assignment of its obligations under Section 3 of this Amendment to a Potential
Partner who undertakes to comply with any and all terms hereof.
 
Accepted and Agreed:
 

Soligenix, Inc.    Sigma-Tau Pharmaceuticals, Inc.           By
/s/ Christopher J. Schaber
  By /s/ David Lemus               Name  Christopher J. Schaber   Name  David
Lemus                 Title President and CEO   Title COO               Date
December 20, 2012   Date December 20, 2012               Enteron
Pharmaceuticals, Inc.                     By /s/ Christopher J. Schaber        
            Name   Christopher J. Schaber                        Title President
and CEO                     Date December 20, 2012