Merger Part of NTMD Plan to Maximize Shareholder Value

Conference Call and Webcast Scheduled for November 18, 2008 at 5:30 pm ET

NitroMed, Inc. (NASDAQ: NTMD) and Archemix Corp., a privately-held biopharmaceutical company working to develop aptamer-based therapeutics, announced today that they have entered into a definitive merger agreement under which Archemix will merge with NitroMed in an all-stock transaction. Under the terms of the merger agreement, NitroMed will issue new shares of its common stock to Archemix stockholders based on an exchange ratio to be determined prior to the closing of the transaction. Under the exchange ratio formula defined in the merger agreement, the former Archemix stockholders are expected to own approximately 70 percent of the combined company, and the former NitroMed stockholders are expected to own approximately 30 percent of the combined company, each on a fully-diluted basis. This ratio is subject to potential adjustments as described in the merger agreement. The name of the company will be changed to Archemix Corp. and will be headquartered at Archemix’s offices in Cambridge, Massachusetts. The merger is subject to approval by Archemix’s and NitroMed’s stockholders and consummation of the previously-announced sale of NitroMed’s BiDil assets and other customary closing conditions.

Archemix is engaged in internal development of aptamer therapeutics in the area of hematologic diseases, and has out-licensed its technology to others to develop their own aptamer therapeutics in other areas. Aptamers are synthetically-derived oligonucleotides that bind to proteins with high specificity and affinity and have been shown to provide many of the advantages of oligonucleotides and monoclonal antibodies. Archemix’s most advanced proprietary candidate, ARC1779, is in Phase 2 clinical development to treat patients suffering from a family of rare blood disorders known as thrombotic microangiopathies, or TMA. A second Archemix proprietary product is scheduled to enter the clinic in mid-2009. In addition, Archemix has licensed its intellectual property to third parties to develop their own aptamer product candidates. Currently, Archemix licensees are evaluating five different aptamer product candidates in human clinical trials; two in Phase 2 and three in Phase 1. Archemix has additional partnerships with several pharmaceutical and biotechnology companies, including Merck Serono, Pfizer, Takeda, Eli Lilly and Isis Pharmaceuticals.

Assuming consummation of the previously-announced sale of NitroMed’s BiDil assets, it is estimated that cash and cash equivalents for the combined company will be approximately $50-60 million at closing.

“We view this merger as the critical second step, following the announced sale of the BiDil business, in our goal of creating value for our shareholders,” said Kenneth M. Bate, President and CEO of NitroMed. “We believe that the combination of NitroMed and Archemix will provide NitroMed’s stockholders with a company that has an exciting technology platform, proprietary products in development, business development opportunities and a solid financial foundation.”

“We believe that Archemix’s aptamer technology is a promising platform for novel drug discovery and development and it has led to a robust pipeline of potentially valuable therapeutics,” said Errol DeSouza, Ph.D., President and CEO of Archemix. “We are pursuing a strategy that enables us to develop a proprietary pipeline as well as develop a network of partnerships with leading pharmaceutical companies. We are very pleased to enter into this transaction, as we believe it will allow us to vigorously pursue this strategy and benefit shareholders of both companies.”

Details of the Proposed Transaction

The merger will take the form of a stock-for-stock merger intended to qualify as a tax-free reorganization. Under the terms of the agreement, all outstanding shares of Archemix’s common stock and preferred stock will be exchanged for shares of NitroMed’s common stock and all outstanding Archemix options and warrants will be assumed by NitroMed and become options and warrants to acquire NitroMed’s common stock.

The Boards of Directors of both companies have unanimously approved the proposed transaction. NitroMed’s and Archemix’s obligations to consummate the merger are subject to approval by the stockholders of both NitroMed and Archemix, as well as other customary conditions, such as the registration with the U. S. Securities and Exchange Commission (“SEC”) of the NitroMed shares to be issued as a result of the merger. In addition, the obligation of Archemix to complete the merger is further subject to the condition that NitroMed have completed the sale of its BiDil business.

In connection with the execution of the merger agreement, certain funds affiliated with HealthCare Ventures LLC, Rho Ventures, Invus Public Equities, L.P., and Care Capital LLC, together owning or controlling an aggregate of approximately 30% of NitroMed’s common stock, have agreed to vote their shares in favor of the transaction and refrain from selling any of the NitroMed shares they hold for three months following the closing of the transaction and 50% of the shares they hold for six months following the closing of the transaction. In addition, stockholders holding approximately 80% of Archemix capital stock have entered into similar agreements whereby they have agreed to vote their Archemix shares in favor of the merger and refrain from selling any of the NitroMed shares they receive in the merger for three months following the closing of the transaction and 50% of the shares they receive in the merger for six months following the closing of the transaction.

NitroMed expects to file a Registration Statement on Form S-4 and related joint proxy statement/prospectus with the SEC.