EntreMed Reports Third Quarter 2009 Financial Results

ROCKVILLE, MD – November 16, 2009 – EntreMed, Inc. (Nasdaq: ENMD), a clinical-stage
pharmaceutical company developing therapeutics for the treatment of cancer, today reported results
for the three- and nine-month periods ending September 30, 2009.

Revenues for the third quarter 2009 were approximately $3,668,000 versus $3,501,000 for the
comparable period a year ago.  The Company reported a net income for the third quarter of
approximately $85,000.  This compares with a net loss of approximately ($3.4 million), or ($0.04) per
share for the same period last year.

Revenues for the nine months ended September 30, 2009 were approximately $3,668,000 versus
$3,501,000 for 2008.  Reported net loss for the first nine months of 2009 was ($6.5 million), or ($0.08)
per share as compared to ($21.3 million) or ($0.26) per share for 2008.  As of September 30, 2009,
EntreMed had cash and short-term investments of approximately $10,028,000.

Kathy Wehmeir-Davis, EntreMed Principle Accounting Officer, commented, “Our financial
results for the third quarter are in line with our projections. We have estimated that the royalty revenue
from sales of Thalomid® for the third quarter will be $3.3 million and that total royalty revenues for
2009 will be approximately $7.0 million.  Our research and development expenses increased in the
third quarter as a result of manufacturing costs, expansion of the ENMD-2076 Phase 1 study in solid
tumors, and continued enrollment in the leukemia and multiple myeloma studies.  At the end of the
quarter, we reported approximately $10 million in cash and short-term investments.  We believe that
these resources, coupled with anticipated royalty inflows and current initiatives to improve our
liquidity, will provide us with sufficient resources to cover planned operations through 2010.”

Michael M. Tarnow, Executive Chairman, commented, “Our third quarter results reflect
successful execution of our focused cost-reduction efforts initiated this year while at the same time
executing our strategy for the acceleration of the ENMD-2076 clinical program. Every member of the
EntreMed team, including the Board, remains enthusiastic and committed to attaining our clinical
development objectives.”

About EntreMed
EntreMed, Inc. is a clinical-stage pharmaceutical company committed to developing
primarily ENMD-2076, a selective angiogenic kinase inhibitor, for the treatment of cancer.
ENMD-2076 is currently in Phase 1 studies in advanced cancers, multiple myeloma, and leukemia.
The Company’s other therapeutic candidates include MKC-1, an oral cell-cycle regulator with
activity against the mTOR pathway currently in multiple Phase 2 clinical trials for cancer, and
ENMD-1198, a novel antimitotic agent currently in Phase 1 studies in advanced cancers.  The
Company also has an approved IND application for Panzem® in rheumatoid arthritis.  Additional
information about EntreMed is available on the Company’s web site at www.entremed.com and in
various filings with the Securities and Exchange Commission.

Forward Looking Statements
This release contains forward-looking statements within the meaning of the Private
Securities Litigation Reform Act with respect to the outlook for expectations for future financial or
business performance (including the timing of royalty revenues and future R&D expenditures),
strategies, expectations and goals. Forward-looking statements are subject to numerous
assumptions, risks and uncertainties, which change over time. Forward-looking statements speak
only as of the date they are made, and no duty to update forward-looking statements is assumed.
Actual results could differ materially from those currently anticipated due to a number of factors,
including those set forth in Securities and Exchange Commission filings under “Risk Factors,”
including risks relating to the need for additional capital and the uncertainty of additional funding;
variations in actual sales of Thalomid®, risks associated with the Company’s product candidates;
the early-stage products under development; results in preclinical models are not necessarily
indicative of clinical results, uncertainties relating to preclinical and clinical trials; success in the
clinical development of any products; dependence on third parties; future capital needs; and risks
relating to the commercialization, if any, of the Company’s proposed products (such as marketing,
safety, regulatory, patent, product liability, supply, competition and other risks).