EntreMed Receives New Patent for 2-Methoxyestradiol Analogs

Patent Covers Compositions and Methods

ROCKVILLE, Md., June 11, 2008—EntreMed, Inc.
(Nasdaq: ENMD), a clinical-stage pharmaceutical company developing therapeutics for the treatment of cancer and inflammatory diseases, today announced the issuance of U.S. Patent No. 7,371,741 covering analogs of 2-methoxyestradiol (2ME2). The patent grants EntreMed composition-of-matter and method of use intellectual property protection through 2025 for analogs of 2ME2 in oncology and a broad range of non-oncology indications, including inflammatory and immune disorders, rheumatoid arthritis, and other diseases characterized by abnormal cell division (mitosis).

Analogs of 2ME2 have been developed by EntreMed to improve metabolic stability and retain or enhance antiproliferative and antiangiogenic properties. Preclinical results demonstrate that certain analogs of 2ME2 can attack tumors on multiple fronts—directly by disrupting microtubules, an intracellular matrix necessary for the rapid division of cancer cells, through inhibition of mitosis and induction of apoptosis, and by blocking blood vessels that feed tumors (angiogenesis inhibition).

U.S. Patent No. 7,371,741 entitled “Estradiol derivatives and pharmaceutical compositions using same,” covers analogs that have been modified at certain positions on the 2-methoxyestradiol structure, yet retain their ability to inhibit cell proliferation. In addition, the ‘741 patent claims methods for treating tumors with compounds having the claimed structural modifications of 2-methoxyestradiol. The ‘741 patent covering the issued claims is owned exclusively by EntreMed.

James S. Burns, EntreMed President & Chief Executive Officer, commented, “This patent is the result of an extensive internal program to identify novel compounds based on our expertise in angiogenesis, cell cycle regulation and cell signaling. This patent further strengthens our intellectual property position in next generation antimitotic and antiangiogenic drugs for the treatment of cancer. ENMD-1198, a lead compound resulting from our analog program, is currently in a Phase 1 study in advanced cancers. We anticipate completion of the study in the second half of 2008. Additional studies, including an expanded Phase 1 or Phase 2 trial, are planned for later this year.”

About EntreMed
EntreMed, Inc. is a clinical-stage pharmaceutical company developing therapeutic candidates primarily for the treatment of cancer and inflammation. MKC-1 is currently in multiple Phase 2 clinical trials for cancer. MKC-1 is an oral cell-cycle regulator with activity against the mTOR pathway. ENMD-1198, a novel antimitotic agent, and ENMD-2076, a selective kinase inhibitor, are in Phase 1 studies in advanced cancers. The Company also has an approved IND application for Panzem(R) in rheumatoid arthritis. EntreMed’s goal is to develop and commercialize new compounds based on the Company’s expertise in angiogenesis, cell-cycle regulation and inflammation—processes vital to the treatment of cancer and other diseases, such as 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
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