Immunomedics Announces Objective Responses in Five Types of Solid Cancer With IMMU-132

Immunomedics Announces Objective Responses in Five Types of Solid Cancer With
IMMU-132

   -- Cancer Types Include Colorectal, Esophageal, Triple-Negative Breast,
                     Small-Cell and Non-Small-Cell Lung –

              -- Preclinical Study on IMMU-132 Also Presented --

CHICAGO, June 2, 2014 (GLOBE NEWSWIRE) -- Immunomedics, Inc., (Nasdaq: IMMU)
today reported that 71% of patients (34 of 48) with diverse metastatic solid
cancers had durable disease stabilization after receiving treatments with the
Company's novel investigational antibody-drug conjugate (ADC), IMMU-132. These
include 7 patients (15%) with colorectal, small-cell and non-small-cell lung,
esophageal, and triple-negative breast cancers showing partial responses with
tumor shrinkage of 30% or more as measured by computed tomography (CT).

"We believe this is the first ADC for solid cancers that is active in so many
cancer types, consistent with the broad increased expression of the target
antigen, TROP-2, in most epithelial cancers," commented Cynthia L. Sullivan,
President and Chief Executive Officer.

IMMU-132 is made up of SN-38, the active metabolite of irinotecan, conjugated
to the Company's humanized anti-TROP-2 antibody. In patients who relapsed or
were refractive to prior topoisomerase I or II inhibitors, this ADC
demonstrated subsequent activity, suggesting that it can overcome resistance
to such inhibitors, including irinotecan.

Even after failing multiple prior therapies, a median time to progression of
at least 12.6 weeks (range 6.0-51.4 weeks) was observed in 48 patients with at
least 1 CT assessment. One patient with hormone-refractive prostate cancer has
a long-term, durable stable disease response, which is approaching a year.
This patient has received 30 doses of IMMU-132 and treatment is continuing.
Despite repeated dosing, no antibodies against the ADC, neither to the
antibody nor to SN-38, have been detected in this or any other patients.

A total of 69 patients with a median of 3 prior therapies have been enrolled
into the multicenter trial, including 13 patients with pancreatic cancer.
Results from the pancreatic cancer patients have recently been presented and
were not included in this report. Please refer to the Company's press release
at http://www.immunomedics.com/pdfs/news/2014/pr05202014.pdf for more
information on the results in pancreatic cancer. Also excluded were 8 patients
who had clinical progression and withdrew before CT assessment.

The Phase I/II results were presented by Alexander Starodub, M.D., Ph.D., of
Indiana University Health Goshen Center for Cancer Care, Goshen, IN, at the
2014 Annual Meeting of the American Society of Clinical Oncology in Chicago,
IL. Earlier at the same Annual Meeting, the Company also presented preclinical
studies on the characterization of IMMU-132.

In animals given the ADC, nearly all of the SN-38 was found to remain bound to
the antibody during blood circulation. As such, IMMU-132 is not toxic to the
animal but maintains SN-38 in a latent, toxic form to be released upon binding
to the TROP-2 antigen on the tumor cells and internalized. In contrast, when
irinotecan is converted to SN-38, a significant amount of the metabolite is
detoxified. As a result, IMMU-132 delivered 120-times higher amounts of SN-38
to the tumors compared to irinotecan at its maximum tolerated dose. This
corroborates the higher therapeutic index believed to be achieved with
IMMU-132 in the clinical studies.

In a variety of human cancers grafted to mice, the ADC produced a broad
spectrum of tumor-growth-inhibition activities, even at doses well below the
maximum tolerated doses in the animal. More importantly, long-term dosing
using smaller, fractionated doses was found to be more effective than larger,
less frequent dosing. This is consistent with the clinical experience where
IMMU-132 is administered on days 1 and 8 of a 21-day cycle, with cycles
repeated for as long as possible. Some patients in the IMMU-132 Phase I/II
trial have been under therapy for up to 11 months.

"These preclinical studies have provided us with important information on the
properties of this promising investigational therapeutic, which we believe has
the potential to be a novel platform for the therapy of diverse metastatic
solid cancers," stated Ms. Sullivan.

About Immunomedics

Immunomedics is a clinical-stage biopharmaceutical company developing
monoclonal antibody-based products for the targeted treatment of cancer,
autoimmune disorders and other serious diseases. Immunomedics' advanced
proprietary technologies allow the Company to create humanized antibodies that
can be used either alone in unlabeled or "naked" form, or conjugated with
radioactive isotopes, chemotherapeutics, cytokines or toxins. Using these
technologies, Immunomedics has built a pipeline of nine clinical-stage product
candidates. Immunomedics has an ongoing collaboration with UCB, S.A. (UCB),
who has worldwide rights in non-cancer indications to Immunomedics' Phase III
product candidate, epratuzumab. UCB expects Phase III data in systemic lupus
erythematosus (SLE) in the first quarter of 2015. Immunomedics is exploring
epratuzumab in oncology in collaboration with outside cancer study groups.
Immunomedics' most advanced wholly owned candidate is ^90Y-clivatuzumab
tetraxetan, which is in an ongoing Phase III registration trial in patients
with pancreatic cancer. Immunomedics' portfolio of wholly owned product
candidates also includes antibody-drug conjugates (ADCs) that are designed to
deliver a specific payload of a chemotherapeutic directly to the tumor while
reducing overall toxicity effects that typically occur when these
chemotherapeutic agents are dosed alone. Immunomedics' most advanced ADCs are
IMMU-132 and IMMU-130, which are in Phase I/II trials for a number of solid
tumors and metastatic colorectal cancer (mCRC), respectively. Immunomedics
also has a number of other product candidates that target solid tumors and
hematologic malignancies, as well as other diseases, in various stages of
clinical and pre-clinical development. These include bispecific antibodies
which have application as T-cell redirecting immunotherapies targeting cancers
and infectious diseases as well as next-generation therapies in cancer and
autoimmune disease. Immunomedics creates these bispecific antibodies using its
patented DOCK-AND-LOCK™ (DNL™) protein conjugation technology. The Company
believes that its portfolio of intellectual property, which includes
approximately 248 active patents in the United States and more than 400
foreign patents, protects its product candidates and technologies.
Immunomedics' strength in intellectual property has resulted in the top-4
ranking in the January 2014 Patent Board scorecard in the Biotechnology
industry. For additional information on the Company, please visit its website
at www.immunomedics.com. The information on its 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 (including the funding therefor, outcomes, timing or associated costs),
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, new product development (including clinical trials outcome and regulatory
requirements/actions), our dependence on UCB for the further development of
epratuzumab for non-cancer indications, risks associated with the outcome of
pending litigation, 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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