EXHIBIT 10.3


AMENDMENT NO. 5 TO

NOTE PURCHASE AGREEMENT


THIS AMENDMENT NO. 5 (the “Amendment”),
dated as of August 17, 2006, is by and between INTERLEUKIN GENETICS, INC., a
Delaware corporation (the “Company”), and
PYXIS INNOVATIONS INC., a Delaware corporation (“Pyxis”).


The Company and Pyxis are parties to a Note Purchase Agreement dated as
of October 23, 2002, as amended November 13, 2002, January 28,
2003, March 5, 2003, and February 23, 2006 (the “Agreement”).  Capitalized terms not otherwise defined in
this Amendment shall have the meanings given to them in the Agreement.


The parties agree as
follows:


1.                                       Recital C of the Agreement is revised to
reflect the following developments since the Initial Closing:


Pyxis has purchased, and the
Company has sold and issued to Pyxis, a promissory note in a principal amount
of $500,000 on each of the following dates: October 23, 2002,
November 14, 2002, December 16, 2002, and January 28, 2003 (the “Existing Notes”).


On March 5, 2003, the
Company and Pyxis entered into a Stock Purchase Agreement (the “Stock Purchase Agreement”) and various agreements referenced
therein (collectively, the “Affiliation Agreements”).  Pursuant to Section 2.5 of the Stock
Purchase Agreement, Pyxis (i)  agreed to extend further credit to the
Company to expand its research partnerships (the “Research
Loans”), and (ii) refinanced the Company’s bridge financing
loans previously due in August 2003 (the “Refinancing Loan”).  In addition, pursuant to Section 2.6 of
the Stock Purchase Agreement, the Company and Pyxis amended and restated the
terms of the Existing Notes.


On March 5, 2005, the
Company and Pyxis amended the Stock Purchase Agreement to extend until
March 5, 2007 the period during which Pyxis agrees to purchase additional
Notes pursuant to Section 2.2B of this Agreement (Research Loans), subject
to the terms and conditions of this Agreement.


On August 17, 2006, the
Company and Pyxis entered into a Stock Purchase Agreement (the “2006 Stock Purchase Agreement”) for the purchase of Common
Stock and extension of a credit facility in an amount not to exceed $14,384,463
in the aggregate, subject to adjustment. 
Under that agreement, Pyxis agrees to purchase Notes pursuant to Section
2.2G of this Agreement, subject to the terms and conditions of this Agreement.


2.                                       The following Sections are amended as
follows:


2.2G        Credit Facility.  At any time prior to August 17, 2008, Pyxis
agrees to purchase, if and when requested by the Company, and upon making such
a request, the Company hereby agrees to sell and issue to Pyxis, one or more
Notes, the aggregate principal amount of which shall not exceed









 



$14,384,463, or such lesser
amount as may result from adjustment under Section 2.5.3 of the Stock Purchase
Agreement (the “Loan Commitment”) (each, a “Working Capital Loan”). 
Subject to the terms and conditions of this Agreement, and the terms and
conditions of the 2006 Stock Purchase Agreement, the closing of these purchases
(each, a “Subsequent Closing”) will take place
within ten business days following the Company’s written request to Pyxis to
make such loan.  For the purposes of each
Working Capital Loan: (a) Pyxis hereby waives each of the closing
conditions set forth in Section 2.5 except Section 2.5.1 (Representations
and Warranties), Section 2.5.2 (Covenants), Section 2.5.3 (Injunction),
Section 2.5.7 (Material Adverse Change, provided, however, that
for this purpose the date set forth in Section 2.5.7 shall be deemed to read
June 30, 2006), Section 2.5.8 (Event of Default), and Section 2.5.12
(Other Documents); and (b) the Company hereby waives each of the closing
conditions set forth in Section 2.4 except Section 2.4.1 (Representations
and Warranties) and Section 2.4.3 (Injunction).  The Working Capital Loans under this Section
2.2G are unsecured obligations; as such they are not subject to the Security
Agreement.


2.2H               Form of Note.  The Note for each Working Capital Loan shall
be in the form set forth as Exhibit B of
the Stock Purchase Agreement dated August 16, 2006 between the Company and
Pyxis.


3.                                       Except as amended hereby, all of the terms
and conditions of the Agreement shall remain in full force and effect. This
Amendment shall be binding upon and inure to the benefit of the parties hereto
and their respective successors and assigns.


This
Amendment No. 5 to Note Purchase Agreement is signed as of the date first
written above.


	
   

  	
  INTERLEUKIN GENETICS, INC

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By

  	
   /s/ Kenneth S. Kornman

  
	
   

  	
   

  	
  Kenneth S. Kornman

  
	
   

  	
   

  	
  President and Chief Executive Officer

  
	
   

  	
   

  
	
   

  	
  PYXIS
  INNOVATIONS INC.

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By

  	
  /s/ Kim S. Mitchell

  
	
   

  	
   

  	
   Kim S. Mitchell

  
	
   

  	
   

  	
  Its Assistant Secretary

  



 



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