DEMAND NOTE

Exhibit 10.2

DEMAND NOTE

FOR VALUE RECEIVED, BIOVEST INTERNATIONAL, INC., a Delaware corporation, (the “Maker”), promises to pay to LAURUS MASTER FUND, LTD. (the “Payee”), ON DEMAND, at c/o Laurus Capital Management, LLC, 825 Third Avenue, 14^th Floor, New York, New York 10022, or at such other place as may be designated in writing by the holder of this Note, the principal sum of TWO MILLION FIVE HUNDRED THOUSAND ($2,500,000) DOLLARS, which sum all be payable in lawful money of the United States of America, together with interest on the unpaid principal balance computed from the date hereof at 2.0% per annum. Interest shall be calculated on the basis of the actual number of days elapsed over a year of 360 days and shall be paid on the first day of each month.

1. DEFAULT INTEREST. In addition to any late payment charge which may be due under this Note, if the principal indebtedness is not paid in full when due, the Maker shall thereafter, pay interest on the principal sum then remaining unpaid from the due date until the date on which the principal sum then outstanding is paid in full (whether before or after judgment), at a rate per annum (calculated for the actual number of days elapsed on the basis of a 360-day year) equal to the rate initially payable hereunder plus 2.0%; provided, however, that such interest rate shall in no event exceed the maximum interest rate which the Maker may by law pay.

2. AUTHORITY. The Maker (and the undersigned representatives of the Maker, if any) represents that the Maker has full power, authority and legal right to execute and deliver this Note and that this Note constitutes a valid and binding obligation of the Maker.

3. DEFINED TERMS. Whenever used, the singular number shall include the plural, the plural the singular, and the words “Payee” and “Maker” shall include, respectively, their respective successors and assigns; provided, however, that the Maker shall in no event or under any circumstance have the right to assign or transfer its obligations under this Note or the related documents, in whole or in part, to any other person, party or entity.

4. HEADINGS, ETC. The headings and captions of the numbered paragraphs of this Note are for convenience of reference only and are not to be construed as defining or limiting, in any way, the scope or intent of the provisions hereof.

5. ENFORCEABILITY. The Maker acknowledges that this Note and the Maker’s obligations under this Note are and shall at all times continue to be absolute and unconditional in

all respects, and shall at all times be valid and enforceable irrespective of any other agreements or circumstances of any nature whatsoever which might otherwise constitute a defense to this Note and the obligations of the Maker under this Note or the obligations of any other person or party relating to this Note. This Note and the instruments and documents referred to herein (collectively and as the same may be amended or otherwise modified from time to time, the “Documents”) set forth the entire agreement and understanding of the Payee and the Maker, and the Maker absolutely, unconditionally and irrevocably waives any and all right to assert any set-off, counterclaim or crossclaim of any nature whatsoever with respect to this Note or the obligations of the Maker hereunder or thereunder, or the obligations of any other person or party relating hereto or thereto or to the obligations of the Maker hereunder or thereunder or otherwise in any action or proceeding brought by the Payee to collect the Note, or any portion thereof, or to enforce, foreclose and realize upon the liens and security interests of the Payee in any collateral (provided, however, that the foregoing shall not be deemed a waiver of the Maker’s right to assert any compulsory counterclaim maintained in a court of the United States, or of the State of New York if such counterclaim is compelled under local law or rule of procedure, nor shall the foregoing be deemed a waiver of the Maker’s right to assert any claim which would constitute a defense, setoff, counterclaim or crossclaim of any nature whatsoever against the Payee in any separate action or proceeding). The Maker acknowledges that no oral or other agreements, conditions, promises, understandings, representations or warranties exist with respect to this Note or with respect to the obligations of the Maker under this Note, except those specifically set forth in this Note and the instruments and documents being signed concurrently herewith.

6. WAIVER. The Maker waives presentment, demand for payment, notice of dishonor and any or all notices or demands in connection with the delivery, acceptance, performance, default or enforcement of this Note and consents to any or all delays, extensions of time, renewals, release of any party to any document related to this Note (collectively the “Documents”), and of any available security therefor, and any and all waivers or modifications that may be granted or consented to by the Payee with regard to the time of payment or with respect to any other provisions of any of the Documents, and agrees that no such action, delay or failure to act on the part of the Payee shall be construed as a waiver by the Payee of, or otherwise affect, in whole or in part, its right to avail itself of any remedy with respect thereto. No notice to or demand on the Maker shall be deemed to be a waiver of the obligation of the Maker or of the right of the Payee to take further action without further notice or demand as provided in any of the Documents.

7. AMENDMENTS. This Note may not be modified, amended, changed or terminated orally, except by an agreement in writing signed by the Maker and the Payee. No waiver of any term, covenant or provision of this Note shall be effective unless given in writing by the Payee and, if so given by the Payee, shall only be effective in the specific instance in which given.

8. GOVERNING LAW. This Note is and shall be deemed entered into in the State of New York and shall be governed by and construed in accordance with the laws of the State of New York, without regard to principles of conflicts of laws.

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IN WITNESS WHEREOF, the Maker has duly executed this Note the day and year first above written.

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