Biovest Secures Worldwide Exclusive License to Late-Stage Technology for Elimination...

Biovest Secures Worldwide Exclusive License to Late-Stage Technology for Elimination of Transplant Rejection

Published Study Shows Revimmune(TM) Reduces the Incidence of
Chronic Bone Marrow Transplant Rejection of Host by Approximately 85%,
Enabling Bone Marrow Transplant Usage to Cure Chronic Illnesses such
as Sickle Cell Anemia
TAMPA, Fla.--(Business Wire)--Biovest International, Inc. (OTCBB:BVTI), a majority-owned
subsidiary of Accentia Biopharmaceuticals, Inc. (NASDAQ:ABPI),
announced today that it has secured the worldwide, exclusive license
to Revimmune(TM) for the treatment and prevention of transplant
rejection including rejection following a bone marrow transplant. As
an initial indication, the Company intends to submit an
Investigational New Drug (IND) application seeking Food and Drug
Administration (FDA) permission to enter a Phase 3 clinical trial of
Revimmune usage in bone marrow transplants to treat and possibly cure
sickle cell anemia, an inherited disease that is chronic and lifelong,
leading to painful crises, organ failure, and strokes. The average
lifespan of an individual with sickle cell anemia is approximately 42
years.

Revimmune is a patent-pending pharmaceutical treatment in
late-stage development for the prevention of transplant rejection,
with applications to bone marrow transplants for a wide variety of
indications including elimination of sickle cell anemia, and other
hereditary hemoglobinopathies such as thalassemia.

According to Biovest's Chairman and CEO, Dr. Steven Arikian,
"Rejection is frequent in bone marrow transplants, as the transplanted
immune system from the donor attacks the organs of the transplant
recipient, and many life-threatening complications occur. With the
acquisition of Revimmune for transplant rejection, we obtain a product
that we believe can improve the percentage of successful transplants,
as evidenced by its ability to dramatically reduce the incidence of
chronic Graft-Versus-Host Disease (GVHD) in bone marrow transplants."
GVHD is a particularly severe type of transplant rejection
characterized by the donor marrow (graft) producing immune cells that
attack multiple organs of the recipient (host).

In clinical studies at Johns Hopkins University Medial Center for
treatment and prevention of transplant rejection including rejection
following a bone marrow transplant, more than 200 patients have been
treated with Revimmune. In a group of 46 bone marrow transplant
patients(1), the use of Revimmune is associated with a reduction in
the incidence of chronic bone marrow transplant rejection of the
recipient by approximately 85%. In particular, transplant patients who
received Revimmune had an incidence of just 11% of chronic GVHD, in
contrast to an incidence of 75% in patients engrafted without
Revimmune. Accordingly, Revimmune has the potential to be the first
effective treatment of this life-threatening complication.

Dr. Arikian explained another key reason why Revimmune may be
ideal for use in bone marrow transplants to cure sickle cell anemia,
"While bone marrow transplant offers the only potential cure for
sickle cell anemia, very few people have a suitable donor for
transplant. Another expected advantage of Revimmune is that its use
expands the potential pool of transplant donors by reducing the
requirement for tissue matching, overcoming a major obstacle of
treatment."

The technology is being licensed to Biovest for transplant
rejection from Revimmune, LLC, a Hopkins Capital Group II LLC (HCG II)
portfolio company, which holds the exclusive license for the
technology from the Johns Hopkins University. Revimmune, LLC has
previously licensed the exclusive, worldwide rights to Revimmune for
treatment of all autoimmune diseases to Accentia Biopharmaceuticals.
Dr. Frank E. O'Donnell Jr. is a managing partner of HCG II. More
details of the license can be found in the Company's 8-K filing. HCG
II is not affiliated with the Johns Hopkins University.

Revimmune for Prevention of Graft-Versus-Host Disease

The principal investigator for the ongoing Revimmune study in bone
marrow transplant patients at Johns Hopkins University School of
Medicine is Dr. Richard Jones. Dr. Jones, Dr. Leo Luznik and
colleagues presented results of the study(1) at a recent meeting:
Post-Transplantation High-Dose Cyclophosphamide (Cy) Is Effective
Single Agent GVHD Prophylaxis That Permits Prompt Immune
Reconstitution after Myeloablative HLA Matched Related and Unrelated
Bone Marrow Transplantation (BMT).

Dr. Jones and Dr. Luznik concluded that the results of the study
indicate that post-transplantation Revimmune (high-dose
cyclophosphamide) is effective as a single agent strategy for limiting
acute and chronic GVHD after myeloablative HLA-matched related and
unrelated allografting; this approach also limits the need for
prolonged immunosuppression, resulting in favorable
immunoreconstitution with few opportunistic infections in this
unfavorable group of patients.

Graft-versus-host disease is a common complication of allogeneic
bone marrow transplantation in which functional immune cells in the
transplanted marrow recognize the recipient as "foreign" and mount an
immunologic attack.

After bone marrow transplantation, T cells present in the graft,
either as contaminants or intentionally introduced into the host,
attack the tissues of the transplant recipient after perceiving host
tissues as antigenically foreign. The T cells produce an excess of
cytokines, including TNF alpha and interferon-gamma (IFNg). A wide
range of host antigens can initiate graft-versus-host disease, among
them the human leukocyte antigens (HLAs). However, graft-versus-host
disease can occur even when HLA-identical siblings are the donors.

While donor T cells are undesirable as effector cells of
graft-versus-host-disease, they are valuable for engraftment by
preventing the recipient's residual immune system from rejecting the
bone marrow graft (host-versus-graft). Additionally, as bone marrow
transplantation is frequently used to cure cancer, mainly leukamias,
donor T-cells have proven to have a valuable graft-versus-tumor
effect.

Background on Sickle Cell Anemia

Sickle-cell anemia and disease (SS) is a group of genetic
disorders caused by sickle hemoglobin (Hgb S or Hb S). In many forms
of the disease, the red blood cells change shape upon deoxygenation
because of polymerization of the abnormal sickle hemoglobin; the
hemoglobin proteins stick to each other, causing the cell to get a
rigid surface and sickle shape. This process damages the red blood
cell membrane, and can cause the cells to become stuck in blood
vessels. This deprives the downstream tissues of oxygen and causes
ischemia and infarction, which may cause organ damage, such as stroke.
The disease is chronic and lifelong. Individuals are most often well,
but their lives are punctuated by periodic painful attacks.

Background on Revimmune

Developed by Dr. Richard Jones, Dr. Robert Brodsky, and colleagues
at Johns Hopkins University School of Medicine, Revimmune uses an
already-approved active pharmaceutical (cyclophosphamide) in a novel,
ultra-high dose, pulsed administration to eliminate unwanted immune
reactions in a new patent-pending method for the treatment and
prevention of a broad range of diseases including transplant rejection
and rejection following a bone marrow transplant, which has been
licensed to Biovest. Revimmune holds the potential to be the first
effective treatment to protect against certain life-threatening
complications associated with transplants, including the prevention of
Graft-Versus-Host Disease. Revimmune includes a risk management
program to enhance patient safety by ensuring appropriate patient
selection, supportive care, and tracking of outcomes data.

References:

(1) Post-Transplantation High-Dose Cyclophosphamide (Cy) Is
Effective Single Agent GVHD Prophylaxis That Permits Prompt Immune
Reconstitution after Myeloablative HLA Matched Related and Unrelated
Bone Marrow Transplantation (BMT). Session Type: ASH Poster Session,
Board #120-III. Luznik Leo, Chen R. Allen, Kaup Michele, Bright C.
Emilie, Bolanos-Meade Javier, Thorburn J. Christopher, Kos Ferdynand,
Hess D. Allan, Jones J. Richard, Fuchs J. Ephraim (Intr. by Leo
Luznik) Division of Hematologic Malignancies, Sidney Kimmel
Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, USA.

About Biovest International, Inc.

Biovest International, Inc. (OTCBB:BVTI) 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 marketed as an automated vaccine manufacturing
instrument and for production of cell-based materials and
therapeutics. Biovest is currently conducting a pivotal Phase 3
clinical trial for BiovaxID(TM), which is a patient-specific
anti-cancer vaccine focusing on the treatment of follicular
non-Hodgkin's lymphoma. BiovaxID(TM) has been granted Fast Track
status by the FDA.

For further information, visit the Company Web site at:
www.biovest.com

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 Revimmune(TM),
BiovaxID(TM), AutovaxID(TM), and any other statements relating to
products, product candidates, product development programs, the FDA or
clinical study process including the commencement, process, or
completion of clinical trials or the regulatory process. Such
statements may include, without limitation, statements with respect to
the 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 the actual results of 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 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
with the Securities and Exchange Commission. All forward-looking
statements are qualified in their entirety by this cautionary
statement, and Biovest undertakes no obligation to revise or update
this news release to reflect events or circumstances after the date
hereof. The product names used in this statement are for
identification purposes only. All trademarks and registered trademarks
are the property of their respective owners.

For Biovest International, Inc., Tampa
Douglas Calder, Director of Investor Relations
& Public Relations, 813-864-2554, ext. 258
Email: dwcalder@accentia.net
or
Susan Bonitz, Ph.D., Director, Program Coordination
813-864-2554, ext. 277
Email: sbonitz@accentia.net

Copyright Business Wire 2008