Clinical Data Repurchases Xmark Fund Warrants and Retires Related Debt.

NEWTON, Mass. -- Clinical Data, Inc. (NASDAQ: CLDA), a worldwide leader in molecular services and clinical diagnostics, announced today that it has completed an agreement with Xmark Opportunity Fund, L.P., ("Xmark") to repurchase a total of 130,000 warrants for total cash consideration of $130,000. Each repurchased warrant carried the right to purchase Clinical Data common stock at a price of $28.50 per share.

In addition, Clinical Data retired a note previously issued to Xmark in the principal amount of $4.5 million. The repurchased warrants and retired note were assumed by Clinical Data in its October 2005 merger with Genaissance Pharmaceuticals, Inc.

Mark D. Shooman, Chief Financial Officer of Clinical Data, commented, "In conjunction with our required retirement of the Xmark debt, we were presented with an opportunity to repurchase the Xmark warrants at an attractive price, and we were pleased to effect this transaction on such favorable terms."

About Clinical Data, Inc.

Clinical Data, Inc. is a worldwide leader in providing molecular services and clinical diagnostics to improve patient care. The Company's pharmacogenomics and molecular services are marketed to the pharmaceutical, biotech, clinical, academic, government and agricultural marketplaces. The Company is utilizing pharmacogenomics to develop molecular diagnostics and more efficacious therapeutics by finding genetic markers to guide drug development and utilization. Its diagnostic and instrumentation business has a market focus on the physician's office, hospital and small-to-medium sized laboratory segments.

SAFE HARBOR STATEMENT UNDER THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995

This press release contains certain forward-looking statements that are intended to be covered by the safe harbor for forward looking statements provided by the Private Securities Litigation Reform Act of 1995. Forward-looking statements are statements that are not historical facts. Words such as "expect(s)", "feel(s)", "believe(s)", "will", "may", "anticipate(s)" and similar expressions are intended to identify forward-looking statements. These statements include, but are not limited to, statements regarding plans, objectives and expectations with respect to future operations, products, services, and scientific outcomes. Such statements are subject to certain risks and uncertainties, many of which are difficult to predict and generally beyond the control of the Company, that could cause actual results to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks and uncertainties include, but are not limited to, those discussed and identified by Clinical Data in public filings with the U.S. Securities and Exchange Commission; the effect on the Company's operations and results of significant acquisitions or divestitures made by major competitors; and the Company's ability to achieve expected synergies and operating efficiencies in all of its acquisitions, and to successfully integrate its operations. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date hereof. Clinical Data does not undertake any obligation to republish revised forward looking statements to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events. Readers are also urged to carefully review and consider the various disclosures in Clinical Data's SEC reports including but not limited to its Annual Report on Form 10-K for the fiscal year ended March 31, 2005, and 2004 and 2005 quarterly reports on Forms 10-QSB and 10-Q.