The Medicines Company Determines Not to Proceed with Proposed Offering.

PARSIPPANY, N.J. -- The Medicines Company (NASDAQ: MDCO) today announced that, based on new information learned at 5:30 p.m. on January 23, 2007, the Company believes that it is possible that some administrative activity may occur in the near term with respect to the Company's application for term extension for the principal patent covering the Company's product Angiomax[R] (bivalirudin). The Company does not know whether any definitive action will be taken or, if taken, whether such action will be favorable or unfavorable. As a result, solely for this reason, the Company has determined not to proceed with its pending public offering of common stock at this time.

Clive Meanwell, Chairman and Chief Executive Officer said, "We were gratified with the way that the offering came together. We regret any inconvenience caused by this decision not to proceed with the offering. It is unfortunate that, at this time, we have such limited information about this possible activity."

About The Medicines Company: The Medicines Company is a pharmaceutical company committed to delivering innovative, cost-effective acute care hospital products in the worldwide hospital marketplace. The Company markets Angiomax[R] (bivalirudin) in the U.S. and other countries for use in patients undergoing coronary angioplasty, a procedure to clear restricted blood flow in arteries around the heart. The Company also has two products in late-stage development, Cleviprex[TM] (clevidipine) and cangrelor.

Statements contained in this press release about The Medicines Company that are not purely historical, and all other statements that are not purely historical, may be deemed to be forward-looking statements for purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. Without limiting the foregoing, the words "believes," "anticipates" and "expects" and similar expressions are intended to identify forward-looking statements. These forward-looking statements involve known and unknown risks and uncertainties that may cause the Company's actual results, levels of activity, performance or achievements to be materially different from those expressed or implied by these forward-looking statements. Important factors that may cause or contribute to such differences include whether we are successful in extending the term of the patent, the extent of the commercial success of Angiomax, , whether the Company's products will advance in the clinical trials process, whether the Company's product candidates will receive approvals from regulatory agencies, and such other factors as are set forth in the risk factors detailed from time to time in the Company's periodic reports and registration statements filed with the Securities and Exchange Commission including, without limitation, the risk factors detailed in the Company's prospectus supplement filed on January 16, 2007, which are incorporated herein by reference. The Company specifically disclaims any obligation to update these forward-looking statements.