Immunomedics Expands Product Pipeline for Potential Therapy of Cancer and Inflammatory...

Immunomedics Expands Product Pipeline for Potential Therapy of Cancer and
Inflammatory Diseases

DENVER, April 20, 2009 (GLOBE NEWSWIRE) -- Immunomedics, Inc. (Nasdaq:IMMU), a
biopharmaceutical company focused on developing monoclonal antibodies to treat
cancer and other serious diseases, today announced the development of IMMU-114,
a humanized monoclonal antibody directed against an immune response target,
HLA-DR, for the potential treatment of cancer. Preclinical results on the
evaluation of this antibody were presented at the 100th Annual Meeting of the
American Association for Cancer Research (AACR).

The in vitro studies examined the reactivity and cytotoxicity of IMMU-114 on a
panel of leukemia cell lines including acute lymphoblastic leukemia (ALL), acute
myelogenous leukemia (AML), chronic lymphocytic leukemia (CLL), chronic
myelogenous leukemia (CML), hairy cell leukemia and mantle cell lymphoma (MCL).
Results demonstrated that IMMU-114 may be useful in the treatment of MCL, ALL,
hairy cell leukemia, and CLL. Previously, in a paper published by the Company in
the October 15, 2006, issue of Blood, the antibody was also shown to exhibit in
vitro and in vivo cytotoxicity on a number of human lymphoma cell lines.

"We continue to expand our repertoire of promising humanized antibodies that
have potential applications for the therapy of cancer and inflammatory
diseases," stated Cynthia L. Sullivan, President and CEO. "Although other HLA-DR
antibodies have been developed," she continued, "IMMU-114 is distinguished by
having a different immunoglobulin class, IgG4, which does not function by the
usual effector-cell activities, such as complement-dependent cytotoxicity (CDC)
and antibody-dependent cellular cytotoxicity (ADCC). As a result, we believe it
is less toxic to patients. We are evaluating its potential activity against
certain solid cancers and autoimmune diseases, and will consider it for future
clinical development," Ms. Sullivan concluded.

HLA-DR, human leukocyte antigen-DR, is a class II major histocompatibility
complex (MHC) cell surface receptor. The antigen is expressed at high levels on
a range of hematological malignancies. As a result, there has been considerable
interest in its development as a target for antibody-based lymphoma therapy.
However, because the antigen is expressed on normal as well as tumor cells,
safety concerns have been raised regarding the clinical use of HLA-DR-directed
antibodies.

About IMMU-114

IMMU-114 is a humanized IgG4 antibody that targets the HLA-DR antigen.
Constructed by complementarity-determining region grafting, the IgG4 antibody
was generated to fill the need for an agent that is able to kill tumor cells
without CDC or ADCC, thereby reducing the reliance on intact immunological
systems in the patient as well as lowering the effector mechanism-related
toxicity. Moreover, because ADCC and CDC are believed to play a major role in
side effects of monoclonal antibody therapy, the abrogation of the effector-cell
functions of IMMU-114 may make it an attractive clinical agent.

About Immunomedics

Immunomedics is a New Jersey-based biopharmaceutical company primarily focused
on the development of monoclonal, antibody-based products for the targeted
treatment of cancer, autoimmune and other serious diseases. We have developed a
number of advanced proprietary technologies that allow us to create humanized
antibodies that can be used either alone in unlabeled or "naked" form, or
conjugated with radioactive isotopes, chemotherapeutics or toxins, in each case
to create highly targeted agents. Using these technologies, we have built a
pipeline of therapeutic product candidates that utilize several different
mechanisms of action. We also have a majority ownership in IBC Pharmaceuticals,
Inc., which is developing a novel Dock-and-Lock (DNL) methodology with us for
making fusion proteins and multifunctional antibodies, and a new method of
delivering imaging and therapeutic agents selectively to disease, especially
different solid cancers (colorectal, lung, pancreas, etc.), by proprietary,
antibody-based, pretargeting methods. We believe that our portfolio of
intellectual property, which includes approximately 134 patents issued in the
United States and more than 300 other patents issued worldwide, protects our
product candidates and technologies. For additional information on us, please
visit our website at www.immunomedics.com. The information on our website does
not, however, form a part of this press release.

This release, in addition to historical information, may contain forward-looking
statements made pursuant to the Private Securities Litigation Reform Act of
1995. Such statements, including statements regarding clinical trials,
out-licensing arrangements (including the timing and amount of contingent
payments), forecasts of future operating results, and capital raising
activities, involve significant risks and uncertainties and actual results could
differ materially from those expressed or implied herein. Factors that could
cause such differences include, but are not limited to, risks associated with
new product development (including clinical trials outcome and regulatory
requirements/actions), our dependence on our licensing partners for the further
development of epratuzumab for autoimmune indications and veltuzumab for
non-cancer indications, competitive risks to marketed products and availability
of required financing and other sources of funds on acceptable terms, if at all,
as well as the risks discussed in the Company's filings with the Securities and
Exchange Commission. The Company is not under any obligation, and the Company
expressly disclaims any obligation, to update or alter any forward-looking
statements, whether as a result of new information, future events or otherwise.

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CONTACT: Immunomedics, Inc.
Dr. Chau Cheng, Associate Director, Investor Relations
& Business Analysis
(973) 605-8200, extension 123
ccheng@immunomedics.com