Biovest to Expand BiovaxID Phase 3 Trial in Ukraine and Russia - Regulatory Documents Filed; Anticipated Addition of More Than 12 New Clinical Sites Puts Company on Track to Complete Enrollment in Late 2007.

WORCESTER, Mass. -- Biovest International, Inc. (OTCBB: BVTI) has filed for regulatory approval to open up to 30 new clinical sites for its pivotal Phase 3 trial of BiovaxID(TM) for the treatment of follicular non-Hodgkin's lymphoma (NHL) -- a major milestone for the Company. The opening of these sites is expected to dramatically increase the number of patients being treated with BiovaxID during the next 12 to 18 months. The filings have been submitted by the contract research organizations which will manage the trials for Biovest in Ukraine and Russia and will be responsible for monitoring patient recruitment and overseeing all aspects of the studies.

"The expansion of our trial into Ukraine and Russia marks a significant advancement for Biovest," said Dr. Steve Arikian, Biovest Chief Executive Officer. "Our data indicate the availability of a large pool of eligible NHL patients eager to participate in the testing of this potentially life-saving therapy. With the addition of these new sites and with other initiatives underway in the U.S., our projections suggest we will be able to move significantly closer toward completing trial enrollment as planned."

Non-Hodgkin's lymphoma, a cancer of the lymphatic system involving a type of white blood cell called a lymphocyte, is found in 65,000 new patients each year in the United States. Although positive response rates are often seen with current treatments such as chemotherapy, radiation, lymphocyte transplantation and monoclonal antibodies, the cancer invariably returns and is usually ultimately fatal. BiovaxID is not meant as a replacement for existing therapies, but rather a complement. It is a targeted therapeutic that stimulates the immune system to seek out and destroy only cancerous B-cell lymphocytes without causing damage to normal B-cell lymphocytes or to other cells.

Biovest is currently enrolling patients for its BiovaxID Phase 3 study, being run in collaboration with the National Cancer Institute through a Cooperative Research and Development Agreement (CRADA). Patients who believe they may be eligible to participate in a clinical trial with BiovaxID are encouraged to visit www.biovest.com/BIOVAXID/patientinfo.html, or call 877-654-6052.

About Biovest International, Inc.

Biovest International, Inc. is a pioneer in the development of advanced individualized immunotherapies for life-threatening cancers of the blood system. Biovest is a majority-owned subsidiary of Accentia Biopharmaceuticals, Inc. (NASDAQ: ABPI), with its remaining shares publicly traded. Biovest has a foundation in the manufacture of biologics for research and clinical trials. In addition, Biovest develops, manufactures and markets patented cell culture systems, including the innovative AutovaxID(TM), which is being developed as an automated vaccine manufacturing instrument and for production of cell-based materials and therapeutics. Biovest's therapy for follicular non-Hodgkin's lymphoma is currently in a Phase 3 pivotal clinical trial at more than 20 major medical centers throughout the U.S., and is being conducted under a Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute. For further information, visit the Company Web site at www.biovest.com.

About Accentia Biopharmaceuticals, Inc.

Accentia Biopharmaceuticals, Inc. is a biopharmaceutical company focused on the development and commercialization of late-stage clinical products in the therapeutic areas of respiratory disease and oncology. Two of these products are SinuNase(TM) and BiovaxID(TM). The Company's SinuNase product, in development to treat chronic sinusitis (rhinosinusitis), is a novel application and formulation of a known anti-fungal licensed from the Mayo Foundation for Medical Education and Research. BiovaxID is a patient-specific anti-cancer vaccine for the treatment of follicular non-Hodgkin's lymphoma. BiovaxID, which is being developed by Accentia subsidiary Biovest International, Inc., is currently in a Phase 3 clinical trial. In addition, Accentia's growing specialty pharmaceutical business, TEAMM Pharmaceuticals, has a portfolio of currently marketed products plus a pipeline of additional products under development by third parties. For further information, visit the Company Web site at www.accentia.net.

Forward-Looking Statements

Statements in this release that are not strictly historical in nature constitute "forward-looking statements." Such statements include, but are not limited to, statements about AutovaxID, BiovaxID and any other statements relating to products, product candidates, and product development programs of Accentia and/or Biovest. Such statement may include, without limitation, statements with respect to either Company's plans, objectives, expectations and intentions and other statements identified by words such as "may", "could", "would", "should", "believes", "expects", "anticipates", "estimates", "intends", "plans" or similar expressions. Such forward-looking statements involve known and unknown risks, uncertainties, and other factors that may cause actual results of either Accentia or Biovest to be materially different from historical results or from any results expressed or implied by such forward-looking statements. These factors include, but are not limited to, risks and uncertainties related to the progress, timing, cost, and results of Accentia's and/or Biovest's clinical trials and product development programs; difficulties or delays in obtaining regulatory approval for product candidates; competition from other pharmaceutical or biotechnology companies; and the additional risks discussed in filings of Accentia and Biovest with the Securities and Exchange Commission. All forward looking statements are qualified in their entirety by this cautionary statement, and neither Accentia nor Biovest undertakes any obligation to revise or update this news release to reflect events or circumstances after the date hereof.