Immunomedics Announces Three New Patent Awards

Immunomedics Announces Three New Patent Awards

The Company Ranked Tenth in the World for US Patents in
Biotechnology/Pharmaceuticals

MORRIS PLAINS, N.J., May 7, 2013 (GLOBE NEWSWIRE) -- Immunomedics, Inc.
(Nasdaq:IMMU), a biopharmaceutical company primarily focused on the
development of monoclonal antibody-based products for the targeted treatment
of cancer, autoimmune and other serious diseases, today announced that it has
received notice that its patent application for "Delivery system for cytotoxic
drugs by bispecific antibody pretargeting," will issue as US patent No.
8,435,539 today.

This patent relates to compositions for pretargeting delivery of therapeutic
agents for use with bispecific antibodies generated by the Company's
proprietary DOCK-AND-LOCK™ (DNL™) protein conjugation technology. The allowed
claims under the patent cover the use of conjugates of therapeutic agents,
such as SN-38, for cancer or other diseases, until the year 2026.

SN-38 is the active form of, and about three orders of magnitude more potent
than, irinotecan or CPT-11,an FDA-approved drug for metastatic colorectal
cancer treatment. The powerful cancer drug cannot be administered systemically
to patients because of its toxicity and poor solubility in water. We have
conjugated SN-38 to two of our humanized antibodies, labetuzumab and hRS7, for
targeted delivery to cancer cells. The two antibody-drug conjugates are being
evaluated in separate Phase I trials for solid cancer therapy.

The Company has also received notice that its patent application for
"Combining radioimmunotherapy and antibody-drug conjugates for improved cancer
therapy," will issue as US patent No. 8,435,529 today. The new patent covers
the use of clivatuzumab and hRS7, and fragments thereof, for the treatment of
pancreatic cancer and other forms of cancer. The allowed claims protect the
use of yttrium-90-labeled clivatuzumab, which is being developed for the
treatment of patients with advanced or metastatic pancreatic cancer, and
hRS7-SN-38 until 2023.

In addition, IBC Pharmaceuticals, Inc., the Company's majority-owned
subsidiary, has received notice that additional claims for the patent
family,"Dimeric alpha interferon PEGylated site-specifically shows enhanced
and prolonged efficacy in vivo," will issue as U.S. patent no. 8,435,540
today.

The new claims, which will expire in March 2026, cover the use of PEGylated
alpha interferon created by DNL™ for the treatment of autoimmune diseases that
include multiple sclerosis and ulcerative colitis.

The Company's strength in intellectual property was recently recognized by the
IEEE Spectrum Patent Power Scorecards, which ranked Immunomedics tenth in the
Biotechnology and Pharmaceuticals category, based on the number and quality of
its U.S. patents issued in 2011, as reflected in characteristics such as
growth, impact, originality, and general applicability of the patents.

The top-10 ranking, above industry giants such as Amgen and Merck, evidences a
substantial improvement in the quality and quantity of U.S. patents issued to
Immunomedics in calendar year 2011. Every other company in the top 10 has
annual sales in the billion dollar range. Considering its intellectual
property strength relative to available resources, Immunomedics is the top
company in its class.

"We are pleased to receive these new patents and the recognition from IEEE
Spectrum," commented Cynthia L. Sullivan, President and Chief Executive
Officer. "These achievements are the result of the quality of research and
development at Immunomedics, and its strong patent prosecution group. Also,
for a second year in a row, we won a prestigious Thomas Alva Edison Patent
Award from the Research and Development Council of New Jersey." "Our
intellectual property portfolio is an important asset in our continuing
licensing efforts for these and other new therapeutics, as well as our novel
approaches to disease management," added Ms. Sullivan.

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, cytokines 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™) method 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 222 active patents in the United States and more
than 400 foreign patents, protects our product candidates and technologies.
Our strength in intellectual property has resulted in the top-10 ranking in
the 2012 IEEE Spectrum Patent Power Scorecards in the Biotechnology and
Pharmaceuticals category. 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, potential
collaborations, 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 any cash payment that the Company might
receive in connection with a sublicense involving a third party and UCB, which
is not within the Company's control, new product development (including
clinical trials outcome and regulatory requirements/actions), our dependence
on our licensing partners for the further development of epratuzumab 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.

CONTACT: For More Information:
         Dr. Chau Cheng
         Senior Director, Investor Relations & Grant Management
         (973) 605-8200, extension 123
         ccheng@immunomedics.com
 
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