Exhibit 10.18

WARRANT TERMINATION AGREEMENT

THIS WARRANT TERMINATION AGREEMENT (this “Agreement”) is made as of November 17,
2010, by and between LAURUS MASTER FUND, LTD. (IN LIQUIDATION), a Cayman Islands
company (“Laurus”), and BIOVEST INTERNATIONAL, INC., a Delaware corporation
(“Biovest”).

RECITALS

WHEREAS, on March 31, 2006, Biovest and Laurus entered into a Note and Warrant
Purchase Agreement (the “Biovest Purchase Agreement”), pursuant to which Laurus
purchased a Secured Promissory Note in the original principal amount of
$7,799,000 from Biovest;

WHEREAS, in connection with the Biovest Purchase Agreement, Biovest executed and
issued to Laurus a Common Stock Purchase Warrant (the “Laurus Warrant”) for the
purchase by Laurus, on or before March 31, 2021, of up to 18,087,889 shares of
the Biovest Common Stock at an exercise price of $0.01 per share;

WHEREAS, pursuant to that certain Term Loan and Security Agreement (the
“Security Agreement”) dated as of November 17, 2010, by and among Biovest, the
Lenders party thereto and LV Administrative Services, Inc., the parties hereto,
in consideration for the acceptance by certain of the Prepetition Lenders of the
allowed secured claims against Biovest as provided therein, have agreed, among
other things, to the termination and cancellation of the Laurus Warrant; and

WHEREAS, pursuant to the terms and conditions of the Security Agreement and the
Confirmed Plan, Laurus and Biovest desire to terminate and cancel the Laurus
Warrant effective as of the date of this Agreement.

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, the parties hereto hereby agree as follows:

1.          Capitalized terms used but not defined herein shall have the
meanings ascribed to them in the Security Agreement.

2.          The parties hereto agree that the above Recitals are true and
correct in all respects.

3.          Laurus hereby consents to the termination and cancellation of the
Laurus Warrant (and all of the rights and obligations created thereunder), and
Biovest hereby cancels the Laurus Warrant, effective as of the date of this
Agreement.

4.          Laurus hereby acknowledges and agrees that it shall have no claims
of any nature whatsoever against Biovest as a result of the termination and
cancellation of the Laurus Warrant.

5.          This Agreement shall be binding upon the parties hereto and their
respective successors and assigns. The parties hereto agree that this Agreement
is fully and adequately supported by consideration, is fair and reasonable, and
that they have had the opportunity to discuss this matter with counsel of their
choice. This Agreement may be executed in one or

 

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more counterparts, each of which shall be deemed an original and all of which
together shall be deemed to constitute one agreement. It is understood and
agreed that if facsimile copies of this Agreement bearing facsimile signatures
are exchanged between the parties hereto, such copies shall in all respects have
the same weight, force and legal effect and shall be fully as valid, binding,
and enforceable as if such signed facsimile copies were original documents
bearing original signature.

6.        THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED, INTERPRETED AND
ENFORCED ACCORDING TO, THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO
PRINCIPLES OF CONFLICT OF LAWS PROVISIONS THEREOF. ANY ACTION BROUGHT CONCERNING
THE TRANSACTIONS CONTEMPLATED BY THIS AGREEMENT SHALL BE BROUGHT ONLY IN THE
STATE COURTS OF NEW YORK OR IN THE FEDERAL COURTS LOCATED IN THE STATE OF
NEW YORK. The prevailing party shall be entitled to recover from the other party
its reasonable attorneys’ fees and costs. Wherever possible each provision of
this Agreement shall be interpreted in such manner as to be effective and valid
under applicable law, but if any provision of this Agreement shall be prohibited
by or invalid under such law, such provision shall be ineffective to the extent
of such prohibition or invalidity, without invalidating the remainder of such
provision or the remaining provisions of this Agreement.

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IN WITNESS WHEREOF, the undersigned have executed this Agreement as of the date
first above written.

 

LAURUS MASTER FUND, LTD. (IN
LIQUIDATION) By:  

/s/ Russell Smith

Name:     Russell Smith Title:     Joint Official Liquidator (with no personal
liability) BIOVEST INTERNATIONAL, INC. By: /s/ David
Moser                                                  Name:     David Moser
Title:     Secretary