Exhibit 10.8

INTELLECTUAL PROPERTY SECURITY AGREEMENT

THIS INTELLECTUAL PROPERTY SECURITY AGREEMENT, dated as of December 10, 2007 is
made by Biovest International, Inc., a Delaware corporation (“Grantor”), in
favor of LV Administrative Services, Inc., as agent (“Agent”).

WITNESSETH:

WHEREAS, pursuant to (i) that certain Note Purchase Agreement dated as of the
date hereof by and between VALENS U.S. SPV I, LLC (“Valens U.S.”) and the
Grantor (as amended, restated, modified and/or supplemented from time to time,
the “Valens U.S. Purchase Agreement”) and (ii) that certain Note Purchase
Agreement dated as of the date hereof by and between VALENS OFFSHORE SPV II,
CORP. (“Valens Offshore”; and together with Agent and Valens U.S., the “Creditor
Parties”) and the Grantor (as amended, restated, modified and/or supplemented
from time to time, the “Valens Offshore Purchase Agreement” and together with
the Valens U.S. Purchase Agreement, each a “Purchase Agreement” and collectively
the “Purchase Agreements”), Creditor Parties provide or will provide certain
financial accommodations to the Grantor; and

WHEREAS, Creditor Parties are willing to make the Loans as provided for in the
Purchase Agreements, but only upon the condition, among others, that Grantor
shall have executed and delivered to Agent, for the ratable benefit of Creditor
Parties, this Intellectual Property Security Agreement;

NOW, THEREFORE, in consideration of the premises and mutual covenants herein
contained and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Grantor hereby agrees as follows:

1. DEFINED TERMS. All capitalized terms used but not otherwise defined herein
have the meanings given to them in the Purchase Agreements.

2. GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY COLLATERAL. To secure the
complete and timely payment of all the Obligations of Grantor now or hereafter
existing from time to time, Grantor hereby pledges and grants to Agent, for the
ratable benefit of Creditor Parties, a continuing first priority security
interest in all of Grantor’s right, title and interest in, to and under the
following, whether presently existing or hereafter created or acquired
(collectively, the “Intellectual Property Collateral”):

(a) all of its Patents and Patent Licenses to which it is a party including
those referred to on Schedule I hereto;

(b) all of its Trademarks and Trademark Licenses to which it is a party
including those referred to on Schedule II hereto;

(c) all of its Copyrights and Copyright Licenses to which it is a party
including those referred to on Schedule III hereto;

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(d) all reissues, continuations or extensions of the foregoing;

(e) all goodwill of the business connected with the use of, and symbolized by,
each Patent, each Patent License, each Trademark, each Trademark License, each
Copyright and each Copyright License; and

(f) all products and proceeds of the foregoing, including, without limitation,
any claim by Grantor against third parties for past, present or future
(i) infringement or dilution of any Patent or Patent licensed under any Patent
License, (ii) injury to the goodwill associated with any Patent or any Patent
licensed under any Patent License, (iii) infringement or dilution of any
Trademark or Trademark licensed under any Trademark License, (iv) injury to the
goodwill associated with any Trademark or any Trademark licensed under any
Trademark License, (v) infringement or dilution of any Copyright or Copyright
licensed under any Copyright License, and (vi) injury to the goodwill associated
with any Copyright or any Copyright licensed under any Copyright License.

3. REPRESENTATIONS AND WARRANTIES. Grantor represents and warrants that Grantor
does not have any interest in, or title to, any Patent, Trademark or Copyright
except as set forth in Schedule I, Schedule II and Schedule III, respectively,
hereto. This Intellectual Property Security Agreement is effective to create a
valid and continuing Lien on and, upon the filing hereof with the United States
Patent and Trademark Office and the United States Copyright Office, perfected
security interests in favor of Agent, for the ratable benefit of Creditor
Parties, in all of Grantor’s Patents, Trademarks and Copyrights and such
perfected security interests are enforceable as such as against any and all
creditors of, and purchasers from, Grantor. Upon filing of this Intellectual
Property Security Agreement with the United States Patent and Trademark Office
and the United States Copyright Office and the filing of appropriate financing
statements, all action necessary or desirable to protect and perfect Agent’s
Lien on Grantor’s Patents, Trademarks and Copyrights shall have been duly taken.

4. COVENANTS. Grantor covenants and agrees with Agent that from and after the
date of this Intellectual Property Security Agreement and until the Termination
Date:

(a) Grantor shall notify Agent immediately if it knows or has reason to know
that any application or registration relating to any Patent, Trademark or
Copyright (now or hereafter existing) may become abandoned or dedicated, or of
any adverse determination or development (including the institution of, or any
such determination or development in, any proceeding in the United States Patent
and Trademark Office, the United States Copyright Office or any court) regarding
Grantor’s ownership of any Patent, Trademark or Copyright, its right to register
the same, or to keep and maintain the same.

(b) In no event shall Grantor, either directly or through any agent, employee,
licensee or designee, file an application for the registration of any Patent,
Trademark or Copyright with the United States Patent and Trademark Office, the
United States Copyright Office or any similar office or agency without giving
Agent prior written notice thereof, and, upon request of Agent, Grantor shall
execute and deliver a supplement hereto (in form and substance satisfactory to
Agent) to evidence Agent’ Lien on such Patent, Trademark or Copyright, and the
General Intangibles of Grantor relating thereto or represented thereby.

 

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(c) Unless an application or registration is not material to Grantor’s business
as determined by Grantor in the exercise of its reasonable business judgment,
Grantor shall take all actions necessary or requested by Agent to maintain and
pursue each application, to obtain the relevant registration and to maintain the
registration of each of the Patents or Trademarks (now or hereafter existing),
including the filing of applications for renewal, affidavits of use, affidavits
of noncontestability and opposition and interference and cancellation
proceedings.

(d) In the event that any of the Intellectual Property Collateral is infringed
upon, or misappropriated or diluted by a third party, Grantor shall notify Agent
promptly after Grantor learns thereof. Grantor shall, unless it shall reasonably
determine that such Intellectual Property Collateral is in no way material to
the conduct of its business or operations, promptly sue for infringement,
misappropriation or dilution and to recover any and all damages for such
infringement, misappropriation or dilution, and shall take such other actions as
Agent shall deem appropriate under the circumstances to protect such
Intellectual Property Collateral.

5. SECURITY AGREEMENT. The security interests granted pursuant to this
Intellectual Property Security Agreement are granted in conjunction with the
security interests granted to Agent in connection with the transactions
contemplated by the Purchase Agreements. Grantor hereby acknowledges and affirms
that the rights and remedies of Agent with respect to the security interest in
the Intellectual Property Collateral made and granted hereby are more fully set
forth in the Purchase Agreements and the Related Agreements referred to therein,
the terms and provisions of which are incorporated by reference herein as if
fully set forth herein.

6. REINSTATEMENT. This Intellectual Property Security Agreement shall remain in
full force and effect and continue to be effective should any petition be filed
by or against Grantor for liquidation or reorganization, should Grantor become
insolvent or make an assignment for the benefit of any creditor or creditors or
should a receiver or trustee be appointed for all or any significant part of
Grantor’s assets, and shall continue to be effective or be reinstated, as the
case may be, if at any time payment and performance of the Obligations, or any
part thereof, is, pursuant to applicable law, rescinded or reduced in amount, or
must otherwise be restored or returned by any obligee of the Obligations,
whether as a “voidable preference,” “fraudulent conveyance,” or otherwise, all
as though such payment or performance had not been made. In the event that any
payment, or any part thereof, is rescinded, reduced, restored or returned, the
Obligations shall be reinstated and deemed reduced only by such amount paid and
not so rescinded, reduced, restored or returned.

7. NOTICES. Whenever it is provided herein that any notice, demand, request,
consent, approval, declaration or other communication shall or may be given to
or served upon any of the parties by any other party, or whenever any of the
parties desires to give and serve upon any other party any communication with
respect to this Intellectual Property Security Agreement, each such notice,
demand, request, consent, approval, declaration or other communication shall be
in writing and shall be given in the manner, and deemed received, as provided
for in the Purchase Agreements.

8. TERMINATION OF THIS SECURITY AGREEMENT. Subject to Section 6 hereof, this
Intellectual Property Security Agreement shall terminate upon the indefeasible
payment in full in cash of the Obligations, and the irrevocable termination of
Creditor Parties commitments to make loans or provide other financial
accommodations under the Purchase Agreements and the Related Agreements referred
to therein.

[Signatures appear on the following page.]

 

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IN WITNESS WHEREOF, Grantor has caused this Intellectual Property Security
Agreement to be executed and delivered by its duly authorized officer as of the
date first set forth above.

 

BIOVEST INTERNATIONAL, INC. By:  

/s/ Steven Arikian

Name:   Steven Arikian, M.D. Title:   Chairman & CEO

ACCEPTED and ACKNOWLEDGED by:

 

LV ADMINISTRATIVE SERVICES, INC., as Agent By:  

/s/ Patrick Regan

Name:   Patrick Regan Title:   Authorized Signatory:

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Schedule I

A. Patents Issued

 

COUNTRY

 

TITLE

 

PATENT NO.

 

ISSUE DATE

U.S.   BIOREACTOR APPARATURS   4,889,812   December 16, 1989 U.S.   BIOREACTOR
SYSTEM   4,894,342   January 16, 2004 U.S.   MULTI-BIOREACTOR HOLLOW FIBER CELL
PROPOGATION SYSTEM AND METHOD   5,656,421   August 12, 1997 U.S.   BASKET-TYPE
BIOREACTOR   5,998,184   December 7, 1999 U.S.   CELL CULTURE APPARATUS  
5,416,022   May 16, 1995 U.S.   PRESSURE CONTROL SYSTEM FOR A BIOREACTOR  
5,330,915   July 19, 1994 U.S.   METHOD OF CULTURING LEUKOCYTES   5,541,105  
July 30, 1996 U.S.   IMMUNOTHERAPY PROTOCOL OF CULTURING LEUKOCYTES IN THE
PRESENCE OF INTERLEUKIN-2 IN A HOLLOW FIBER CARTRIDGE   5,631,006   May 20, 1997
U.S.   HOLLOW FIBER CELL CULTURE DEVICE AND METHOD OF OPERATION   4,804,628  
February 14, 1989 U.S.   METHOD OF CULTURING CELLS USING HIGHLY GAS SATURATED
MEDIA   4,973,558   November 27, 1990 U.S.   MICRO HOLLOW FIBER BIOREACTOR  
6,001,585   December 14, 1999 U.S.   HIGH PERFORMANCE CELL CULTURE BIOREACTOR
AND METHOD   5,622,857   April 22, 1997 U.S.   CELL CULTURE INCUBATOR  
5,882,918   March 16, 1999

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Schedule I

B. Patents Applications

Extra-Capillary Fluid Cycling System and Method for a Cell Culture Device:

U.S. App. No. 11/802,250, filed 5/21/07 (corresponds to PCT App. No.
PCT/US07/12053, filed 5/21/07)

Interface of a Cultureware Module in a Cell Culture System and Installation
Method Thereof:

U.S. App. No. 11/802,251, filed 5/21/07 (corresponds to PCT App. No.
PCT/US07/12052, filed 5/21/07)

Media Circulation System for a Cell Cultureware Module:

U.S. App. No. 11/802,252, filed 5/21/07 (corresponds to PCT App. No.
PCT/US07/12054, filed 5/21/07)

Method and System for the Production of Cells and Cell Products and Application
Thereof:

U.S. App. No. 11/802,253, filed 5/21/07 (corresponds to PCT App. No.
PCT/US07/12042, filed 5/21/07)

Rotary Actuator Valve for a Cell Culture System:

U.S. App. No. 11/802,254, filed 5/21/07 (corresponds to PCT App. No.
PCT/US07/12051, filed 5/21/07)

 

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Schedule I

C. Patents Licenses

None.

 

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Schedule II

A. Trademark Registrations

 

COUNTRY

  

TRADEMARK

   REG. NO.   

REG. DATE

   RENEWAL DATE U.S.    ACUSOFT    1432743    March 17, 1987    U.S.    ACUSYST
– JR    1440510    May 26, 1987    U.S.    ACUSYST –MAXIMIZER    2379677   
August 22, 2000    U.S.    ACUSYST – P    1391480    April 29, 1986    U.S.   
ACUSYST – S    1430944    May 19, 1987    U.S.    ACUSYST – XCELL    2379695   
August 22, 2000    U.S.    BIO-CONCENTRATOR    1463384    November 3, 1987   
U.S.    BIOMEM    1429936    February 24, 1987    U.S.    BIOVEST    78449977   
July 13, 2004    U.S.    BIOVEST    78449968    July 13, 2004    U.S.    BIOVEST
   78449930    July 13, 2004    U.S.    BIOVAX    76504159    April 4, 2003   
U.S.    BIOVAXID    78346216    December 29, 2003    U.S.    CELL-PHARM   
1429937    February 24, 1987   

 

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Schedule II

B. Trademark Applications

 

COUNTRY

 

TRADEMARK

 

SERIAL NO.

 

FILE DATE

U.S.   BIOVEST   78449977   July 13, 2004 U.S.   BIOVEST   78449968   July 13,
2004 U.S.   BIOVEST   78449930   July 13, 2004 U.S.   BIOVAXID   78346216  
December 29, 2003

 

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Schedule II

C. Trademark Licenses

None.

 

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Schedule III

A. Copyright Registrations

None.

 

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Schedule III

B. Copyright Applications

None.

 

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Schedule III

C. Copyright Licenses

None.

 

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