BIOVEST INTERNATIONAL INC
AGREEMENT RE: FIRST RIGHT OF REFUSAL
<DOCUMENT>
<TYPE>EX-10
<SEQUENCE>12
<FILENAME>biovest8kjune2003ex-10.txt
<DESCRIPTION>AGREEMENT RE: FIRST RIGHT OF REFUSAL
<TEXT>

                                                                      EXHIBIT 10

                                    AGREEMENT

     THIS AGREEMENT is made and entered into as of this 16th of June 2003 by and
among  Biovest  International,  Inc.,  a Delaware  corporation  ("Biovest")  and
Accentia, Inc., a Florida corporation ("Accentia") RECITALS:

     WHEREAS,  Biovest and Accentia  have entered into an  Investment  Agreement
dated April 10, 2003,  which was amended by an Amendment to Agreement dated June
16th, 2003 (collectively referred to as the Investment Agreement);

     WHEREAS,  pursuant to the Investment Agreement,  Accentia is purchasing 81%
of the outstanding capital stock of Biovest;

     WHEREAS, as a material inducement for Accentia to enter into the Investment
Agreement and to purchase shares of Biovest capital stock, Biovest has agreed to
grant  Accentia  the right to maintain  its  ownership  of Biovest at 81% of the
outstanding capital stock of Biovset (the "First Right of Refusal"); and

     WHEREAS,  the parties wish to enter into this  Agreement  setting forth the
terms and provisions of the First Right of Refusal.

     NOW  THEREFORE,  in  consideration  of the  mutual  covenants,  agreements,
representations  and warranties  contained  herein,  the parties hereto agree as
follows:

1.   First  Right of Refusal -  Accentia  is hereby  granted  the  absolute  and
     unconditional  right, in the exercise of its sole  discretion,  to purchase
     that number of shares of Biovest  common stock that may,  from time to time
     during  the  First  Right  of  Refusal  Period,  be  required  to  maintain
     Accentia's  ownership  of  Biovest at 81% of the then  outstanding  capital
     stock of Biovest.  Should Biovest,  for any reason, issue any shares of its
     capital  stock  during the First Right of Refusal  Period (the  "Triggering
     Shares"),  Accentia  shall have the  absolute  and  unconditional  right to
     purchase  that number of  additional  shares  (the "First  Right of Refusal
     Shares") of Biovest  authorized but unissued  common stock that is required
     to cause  Accentia's  ownership  of  Biovest  to equal  81% of the  Biovest
     capital  stock  then  outstanding   following  the  issuance  of  both  the
     Triggering  Shares and the First  Right of Refusal  Shares..  For  purposes
     hereof, the grant or issuance by Biovest of right, convertibles, options or
     warrants,  or other  instruments  during the First Right of Refusal  Period
     which may be converted or result in the issuance of shares of capital stock
     of Biovest  during or after the First Right of Refusal  Period shall result
     in Accentia having a First Right of Refusal with regard thereto.  The First
     Right of  Refusal  applies  to all  shares  which may be issued by  Biovest
     during the First  Right of Refusal  Period  including,  but not limited to,
     shares  issued  in  new  financings,   acquisitions,  options  and  warrant
     exercises and the conversion of convertible notes.

2.   First  Right of Refusal  Period - The First Right of Refusal  Period  shall
     commence  on the date  hereof and end on the last day on which any



<PAGE>

     Biovest  option,  warrant or  convertible  note  listed on Exhibit A hereto
     remains outstanding or in effect.

3.   Purchase  Price - The  purchase  price to be paid by Accentia for the First
     Right of Refusal  Shares  shall be an amount equal to the  aggregate  price
     paid by the third party for the Triggering Shares (i.e., the Accentia First
     Right of  Refusal  Purchase  Price  for all  shares  required  to  maintain
     Accentia's  ownership  at 81% of the then  outstanding  capital  stock will
     equal the  aggregate  price  paid by the third  party for all of the shares
     which  triggered  the First Right of Refusal as opposed to matching the Per
     Share Purchase Price paid by the third party.  The Per Share Purchase Price
     to be paid by Accentia  shall be the aggregate  Purchase  Price (i.e.,  the
     aggregate purchase price paid by the third party for the Triggering Shares)
     divided  by the  total  number  of First  Right  of  Refusal  Shares  being
     purchased by Accentia (the "Per Share Purchase  Price").  Accordingly,  the
     Accentia   First  Right  of  Refusal  Per  Share   Purchase  Price  may  be
     significantly  lower  than the per share  purchase  price paid by the third
     party for the Triggering Shares.

4.   Payment  of  Purchase  Price - The Per Share  Purchase  Price  may,  in the
     discretion  of  Accentia,  be  either  be  paid  in  cash  or by  five-year
     Promissory Note bearing the lowest rate of interest permitted by applicable
     corporate  law. In the event of payment by promissory  note, the Promissory
     Note shall be an  unsecured  corporate  obligation  of  Accentia  and shall
     provide for all interest and principal to be paid in one installment at the
     maturity of the Promissory Note.

5.   Unconditional.  The First Right of Refusal is an absolute and unconditional
     right  granted  to  Accentia  and  constitutes  a material  inducement  for
     Accentia to enter into the  Investment  Agreement  and to purchase  capital
     stock of  Biovest.  Other than as  expressly  set forth in this  Agreement,
     there are no conditions or  limitations on the First Right of Refusal or on
     Accentia's right to purchase  additional  authorized but unissued shares of
     Biovest  common  stock  pursuant  to the First  Right of  Refusal.  Biovest
     acknowledges  and agrees  that the First Right of Refusal may result in the
     issuance of a significant  number of additional  shares of Biovest  capital
     stock to Accentia at Per Share Purchase  Prices which may be  significantly
     less that the then  current  market  price or  appraisal  value of  Biovest
     capital stock. Biovest agrees that during the First Right of Refusal Period
     to maintain sufficient authorized but unissued capital stock to fulfill its
     obligations under the First Right of Refusal.  Biovest agrees, at its cost,
     to defend the validity and  enforcibilty of this Agreement and to indemnify
     Accentia  from any cost,  expense  or loss  arising  from or related to any
     claim or action arising out of or relating to this Agreement.

6.   Notice - Upon any event  which  gives  rise to  Accentia's  First  Right of
     Refusal,  Biovest shall provide  Accentia with written notice of Accentia's
     First Right of Refusal  together with a calculation  of Per Share  Purchase
     Price  and the  number  of First  Right of  Refusal  Shares  available  for
     purchase.  Accentia  shall  have 30  calendar  days  after  receipt of such
     written  notice to provide  Biovest with written  notice of its exercise of
     the First Right of Refusal.


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7.   Miscellaneous

     a.   Assignability  - This Agreement  shall be binding upon and shall inure
          to the  benefit of the parties and their  assigns  and  successors  in
          interest.

     b.   Law This Agreement  shall be construed in accordance  with the laws of
          the State of Florida.

     c.   Survival - This Agreement and all undertakings in this Agreement shall
          survive not only this  Agreement,  but the  closing of the  Investment
          Agreement between the parties.

     d.   Headings - All paragraph  headings herein are inserted for convenience
          of the  parties  only and are not part of, and shall  not,  in any way
          modify  or  affect  the  construction  of  or  interpretation  of  any
          provision of this Agreement.

     e.   Counterparts  -  This  Agreement  may  be  executed  in  one  or  more
          counterparts,  each of which  shall be deemed to be an  original,  and
          which together  shall  constitute  one and the same  instrument.  This
          Agreement  may be executed by fax with fax  execution  having the same
          legal effect as an original signature.

     f.   Notices - Any notice required to be given hereunder or any election of
          the First Right of Refusal shall be in writing,  personally delivered,
          or sent by certified  mail,  or by telecopy at the addresses set forth
          hereinbelow:

                        ACCENTIA:
                                           Accentia, Inc.
                                           5310 Cypress Center Drive, Suite 101
                                           Tampa, Florida 33609
                                           Fax: (813) 287-6643
                         Copy to:
                                           Samuel S. Duffey
                                           416 Burns Court
                                           Sarasota, Florida 34236
                                           Fax: (941) 954-5825

                                           Francis E. O'Donnell, Jr., M.D.
                                           709 The Hamptons Lane
                                           Town & Country, Missouri 63017
                                           Fax: (314) 434-7030
                         BIOVEST:
                                           Biovest International, Inc.
                                           8500 Evergreen Blvd.
                                           Minneapolis, MN 55433
                                           Fax: (763) 786-0915


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                         Copy to:
                                           David Moser


                                           Fax:

     g.   Prior  Agreement - Any conflict  between this  Agreement and any prior
          letters  of intent,  deal  points and  agreements  including,  but not
          limited  to the  Investment  Agreement,  shall  be  governed  by  this
          Agreement.

     IN WITNESS  WHEREOF,  the parties hereto have executed this Agreement as of
the day and year first above written.

Accentia, Inc.                             Biovest International, Inc.



By:                                        By:
     ----------------------------               --------------------------------
Its:                                       Its:




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