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|   | 1. | Incorporation of Recitals.  The parties hereto acknowledge and agree that the recitals hereinabove set forth are true and correct in all respects and that the same are incorporated herein and made a part hereof. |
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|   | 2. | Representations. |
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|   | (a) | Sublandlord  hereby represents and warrants to Subtenant the following facts: |
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|   | (1) | Except as modified by this Third Amendment, the Sublease is in full force and effect and constitutes the entire rental agreement between Sublandlord and Subtenant for the Sublease Premises; |
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|   | (2) | There are no existing defaults on the part of Sublandlord, or to Sublandlord’s knowledge, Subtenant under the Sublease; |
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|   | (3) | Neither Prime Landlord nor Sublandlord is in default under the Prime Lease, and to Sublandlord's knowledge, there exists no state of facts and no event has occurred which, with the passage of time or the giving of notice, or both, would constitute a default by either Prime Landlord or Sublandlord under the Prime Lease; and |
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|   | (4) | Sublandlord has paid to Prime Landlord any and all sums owed to Prime Landlord under the Prime Lease as of the date of this Third Amendment; |
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|   | (5) | To Sublandlord's knowledge, no part of the Security Deposit has been applied by Prime Landlord to satisfy Sublandlord’s obligations under the Prime Lease; |
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|   | (6) | Sublandlord has no knowledge of any environmental condition that affects the use or operation in any way of that portion of the Premises not currently being occupied by Subtenant. |
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|   | (b) | Subtenant hereby represents and warrants to Sublandlord the following facts: |
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|   | (1) | Except as modified by this  Third Amendment, the Sublease is in full force and effect and constitutes the entire rental agreement between Sublandlord and Subtenant for the Sublease Premises; |
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|   | (2) | Subtenant is in full and complete possession of the Sublease Premises; and |
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|   | (3) | There are no existing defaults on the part of Subtenant, or to Subtenant’s knowledge, Sublandlord, under the Sublease. |
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|   | 3. | Option to Renew.  Subtenant hereby exercises its Option, as described in Section 5 of the Second Amendment to Sublease Agreement.  The Option Term shall commence on October 1, 2011 and shall continue for a period of two years (2) and eleven (11) months, expiring on August 31, 2014.  The parties hereto acknowledge and agree that the Option Term set forth herein is one (1) month less than the length of the Option Term as originally set forth in the Second Amendment to Sublease Agreement.  Subtenant shall have no further right to extend the term of the Sublease. |
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|   | 4. | Rent for the Option Term.  Notwithstanding anything to the contrary set forth in the Second Amendment to Sublease Agreement, Subtenant shall pay to Sublandlord, in the manner set forth in Section 6 of the Second Amendment to Sublease Agreement, the following Subrent for the remainder of the Term and for the Option Term: |
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| Period                    |   | Amount psf |   |   | Annual Amount |   |
|---------------------------|--------|-----------------|--------|--------|--------------------|--------|
|                      |   |            |   |   |               |   |
| 01/01/11 – 10/31/11 |   | $               | 8.51   |   |               | $      | 280,047.08 |   |
|                      |   |            |   |   |               |   |   |   |
| 11/01/11 – 10/31/12 |   | $               | 8.73   |   |               | $      | 287,286.84 |   |
|                      |   |            |   |   |               |   |   |   |
| 11/01/12 – 10/31/13 |   | $               | 8.94   |   |               | $      | 294,197.52 |   |
|                      |   |            |   |   |               |   |   |   |
| 11/01/13 – 08/31/14 |   | $               | 9.17   |   |               | $      | 301,766.36 |   |

|   | 5. | Operating Expenses/Utilities.  For the remainder of the Term and continuing through the Option Term, Subtenant shall continue to reimburse Sublandlord for all Operating Expenses and Utilities pursuant to Section 6(b) of the Second Amendment to Sublease Agreement. |
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|   | 6. | Security Deposit/Letter of Credit.  Section 6(d) of the Sublease is hereby deleted, and the following new paragraph (d) is substituted in lieu thereof: |
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|   | 7. | Brokerage Commissions.  Sublandlord and Subtenant represent to each other that neither party has engaged a broker or other person who may be owed a commission in connection with the transactions contemplated by this Third Amendment other than Scheer Partners, which represents Sublandlord and will be paid separately by Sublandlord pursuant to a separate written agreement, and no other broker is entitled to a leasing commission in connection with the transaction effectuated hereby.  Sublandlord and  Subtenant shall indemnify and hold each other harmless against all claims, damages, costs or expenses, including reasonable attorney’s fees and litigation costs, resulting directly or indirectly from any claim by any other party for brokerage or similar fees or commissions arising as a result of its agreement or actions relating to the transaction effectuated hereby. |
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|   | 8. | Continuing Agreements; Novation.  Except as expressly modified hereby, the parties hereto ratify and confirm each and every provision of the Sublease as if the same were set forth herein.  In the event that any of the terms and conditions in the Sublease conflict in any way with the terms and provisions hereof, the terms and provisions hereof shall prevail.  The parties hereto covenant and agree that the execution of this Third Amendment is not intended to and shall not cause or result in a novation with regard to the Sublease. |
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|   | 9. | ENTIRE AGREEMENT.  NO STATEMENTS, AGREEMENTS OR REPRESENTATIONS, ORAL OR WRITTEN, WHICH MAY HAVE BEEN MADE TO EITHER PARTY OR TO ANY EMPLOYEE OR AGENT OF EITHER PARTY, EITHER BY SUCH PARTY OR BY ANY EMPLOYEE, AGENT OR BROKER ACTING ON SUCH PARTY’S BEHALF, WITH RESPECT TO THE MODIFICATION OF THE SUBLEASE, SHALL BE OF ANY FORCE OR EFFECT, EXCEPT TO THE EXTENT STATED IN THIS FIRST AMENDMENT, AND ALL PRIOR AGREEMENTS AND REPRESENTATIONS WITH RESPECT TO THE MODIFICATION OF THE SUBLEASE ARE MERGED HEREIN. |
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|   | 10. | Capitalized Terms.   Each capitalized term used herein but not defined shall have the meaning ascribed to such term in the Sublease. |
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|   | 11. | Captions.  The captions herein set forth are for convenience only and shall not be deemed to define, limit or describe the scope or intent of this Third Amendment. |
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|   | 12. | Governing Law.  The provisions of this Third Amendment shall be construed, interpreted and enforced in accordance with the laws of the Commonwealth of Pennsylvania as the same may be in effect from time to time. |
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|   | 13. | Counterparts.  This Third Amendment may be executed in any number of counterparts, and each such counterpart shall be deemed to be an original.  It shall not be necessary that the signature of, or on behalf of, each party, or that the signatures of the persons required to bind any party, appear on more than one counterpart. |
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|   | 14. | Sublease by Subtenant.  If Subtenant desires to sublet the Premises pursuant to Section 18 of the Prime Lease, Sublandlord shall use commercially reasonable efforts to assist Subtenant in obtaining the necessary approvals from the Prime Landlord and shall be reasonable in whether or not to provide its own consent to any such sublet. |
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| WITNESS:      |   | SUBLANDLORD:   |
|---------------|--------|----------------|
|          |   |           |
|          |   | Novavax, Inc.  |
|          |   |           |   |
|     |   | By:            | /s/ Frederick W. Driscoll |
|          |   | Name:          | Frederick W. Driscoll |
|          |   | Title:         | VP, CFO & Treasurer |
|          |   |           |   |
| WITNESS:      |   | SUBTENANT:     |
|          |   |           |
|          |   | PuriCore, Inc. |
|          |   |           |   |
|     |   | By:            | /s/ Darren D. Weiss |
|          |   | Name:          | Darren D. Weiss |
|          |   | Title:         | Chief Financial Officer |

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