POSITIVE RESULTS WITH BIOGEN’S A1 ADENOSINE RECEPTOR ANTAGONIST IN CONGESTIVE HEART FAILURE PRESENTED AT AMERICAN COLLEGE OF CARDIOLOGY

Biogen, Inc. (NASDAQ/BGEN) and CV Therapeutics, Inc. (NASDAQ/CVTX) today announced that positive results were presented at the annual meeting of the American College of Cardiology from a Phase II trial with Biogen’s A1 adenosine receptor antagonist BG9719 (CVT-124) in patients with moderate congestive heart failure (CHF) on standard therapy. Encouraged by these results, Biogen intends to begin clinical trials soon with its second generation A1 adenosine receptor antagonist, BG9928.

Decrease in renal function is common in CHF disease and is associated with adverse clinical outcomes. The purpose of the Phase II study was to evaluate the effect of Biogen’s A1 adenosine receptor antagonist on renal function. The Phase II trial was a randomized, double-blind, placebo-controlled, cross-over study designed to compare the effects of single doses of BG9719 alone, BG9719 in combination with furosemide, and furosemide alone. The study patients had New York Heart Association class II and III heart failure, with significantly compromised cardiac function and the presence of edema despite adequate medical therapy. All patients were taking ACE inhibitors before, and during the study.

Treatment with BG9719, compared to placebo, resulted in an improvement in renal function, as measured by creatinine clearance, as well as an increase in renal output, without a significant increase in potassium excretion. In contrast, creatinine clearance decreased with standard therapy. When given with standard therapy, BG9719 protected against the decline in renal function and further increased renal output.

Burt Adelman, M.D., Biogen’s Vice President, Medical Research said, “We are encouraged by the results of this trial which combined our A1 adenosine receptor antagonist with standard therapy in congestive heart failure. Therapies that reverse compromised kidney function in patients with decreased cardiac output address a critical unmet medical need. We are aggressively moving forward with the development of our second generation molecule, and believe that it may lead to a successful novel approach for treatment of patients with congestive heart failure.”

Biogen licensed the program to develop and market an A1 adenosine receptor antagonist from CV Therapeutics of Palo Alto, California. Biogen has worldwide rights for all medical indications.

Congestive heart failure is one of the nation’s largest health problems. There are more than five million people in the United States diagnosed with this disease and an estimated worldwide total of ten million. In the U.S., alone, there are about 250,000 deaths each year due to CHF. Despite advances in heart treatments, it is the only remaining cardiovascular disease that is still increasing. For people over the age of sixty-five, CHF is the leading cause of hospitalization. Approximately one million hospitalizations each year in the U.S. are attributed to a primary diagnosis of congestive heart failure.

In addition to historical information, this press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. Reference is made in particular to statements regarding continuation of clinical studies and development of BG9928. These statements are based on the companies’ current beliefs and expectations as to such future outcomes. Factors which could cause actual results to differ materially from the companies’ current expectations include the risk that BG9928 will not yield the same clinical results as the molecule that was the subject of the completed Phase II trial or that problems or delays may arise during preparations for future clinical trials or in the conduct of such trials or that problems may arise with respect to toxicology, formulation of manufacturing of the new molecule, as well as the other risks and uncertainties described from
time to time in Biogen’s periodic reports filed with the Securities and Exchange Commission. Drug development involves a high degree of risk. Success in early stage clinical trials does not ensure that later stage or larger scale clinical trials will be successful.

Biogen, Inc., winner of the U.S. National Medal of Technology, is a biopharmaceutical company principally engaged in discovering and developing drugs for human healthcare through genetic engineering. Headquartered in Cambridge, MA, the Company’s revenues are generated from international sales of AVONEX® (Interferon beta-1a) for treatment of relapsing forms of multiple sclerosis, and from the worldwide sales by licensees of a number of products, including alpha interferon and hepatitis B vaccines and diagnostic products ( Prescribing Information ). Biogen’s research and development activities are focused on novel products to treat inflammatory and autoimmune diseases, neurological diseases, cancer, fibrosis and congestive heart failure. The Company maintains active clinical research programs in protein therapeutics, small molecules, genomics and gene therapy. For copies of press releases and additional information about the Company, please consult Biogen’s Homepage on the World Wide Web at http://www.biogen.com.

CV Therapeutics, Inc., headquartered in Palo Alto, CA, is a biopharmaceutical company focused on applying molecular cardiology to the discovery, development and commercialization of novel, small molecule drugs for the treatment of cardiovascular diseases. CVT currently has three compounds in clinical trials. Ranolazine, the first in a new class of compounds known as partial fatty acid oxidation (pFOX) inhibitors, is in Phase III clinical trials for the potential treatment of chronic angina. CVT-510, an A1 adenosine receptor agonist, is in Phase II clinical trials for the potential treatment of atrial arrhythmias. CVT-3146, an A2A adenosine receptor agonist, is in Phase I clinical trials for the potential use as an adjunctive pharmacologic agent in cardiac perfusion imaging studies. For more information, please visit CV Therapeutics’ web site at http://www.cvt.com.