Metabasis Therapeutics Announces Collaboration with Roche to Develop Liver-Targeted Compounds for the Treatment of Hepatitis C

Metabasis Therapeutics Announces Collaboration with Roche to Develop Liver-Targeted Compounds for the Treatment of Hepatitis C

SAN DIEGO, Aug 07, 2008 - Metabasis Therapeutics announced today that it has entered into a two-year research collaboration agreement with Roche to apply Metabasis' HepDirect(R) liver-targeting technology to Roche's proprietary lead nucleosides in order to develop new treatments for hepatitis C virus (HCV).

Under the terms of the agreement, Roche will provide a $10 million upfront payment. In the event a development candidate is identified, Roche will assume development responsibility, and Metabasis will be eligible to receive up to $193 million in additional payments upon achievement of predetermined preclinical and clinical development events, as well as regulatory and commercialization events for each product. For any marketed products that result from the collaboration, Roche will retain full commercial rights and pay Metabasis a royalty on net sales.

Dr. Mark Erion, Metabasis' chief scientific officer and executive vice president of research and development, stated, "The HepDirect technology has shown significant promise in delivering the activated form of certain antiviral nucleosides to the liver and therefore has the potential to both enhance the antiviral activity of these nucleosides, as well as to lower the effective dose. A partnership with Roche enables Metabasis and Roche to combine their respective strengths in liver-targeting and hepatitis C research with the hope that this combination will lead to a drug candidate for HCV in the near future."

"We are very pleased to form this alliance with Roche, a global healthcare company that is a leader in the discovery and development of drugs and tests for HCV," commented Dr. Ed Baracchini, senior vice president of business development for Metabasis Therapeutics. "Evidence of the ability of our HepDirect technology to target drugs to the liver has been seen with the three internally-generated product candidates that we have put in the clinic that employ this technology. As evidenced by this collaboration, the HepDirect technology platform has garnered considerable attention within the pharmaceutical industry over the past several years. This collaboration is just one of several business development initiatives that we are currently pursuing with respect to Metabasis' many assets."

About Hepatitis C:

HCV, an infection of the liver from a virus, is a highly infectious and potentially fatal disease contracted through blood and bodily fluid contact. The World Health Organization (WHO) estimates that there are more than 170 million people infected with HCV worldwide. According to the Centers for Disease Control and Prevention (CDC), HCV is the most common chronic blood-borne infection in the United States, with annual deaths due to complications from this disease currently around 10,000 and expected to triple by 2010. HCV causes liver inflammation and when the disease becomes chronic, it can lead to scarring of the liver (cirrhosis), liver failure and cancer. Liver failure due to chronic HCV is the leading cause of liver transplantation today.

About Metabasis (www.mbasis.com):

Metabasis is a biopharmaceutical company using its proprietary technologies, scientific expertise and unique capabilities for targeting the liver and liver pathways. The Company has established a broad pipeline of product candidates and advanced research programs targeting large markets with significant unmet needs. Metabasis' core area of focus is on the discovery and development of drug candidates to treat metabolic diseases such as hyperlipidemia and diabetes, among others. Although not a core focus of the Company, Metabasis has also discovered and developed drug candidates indicated for the treatment of liver diseases such as hepatitis and primary liver cancer, which it now intends to license or partner. All product candidates were developed internally using proprietary technologies.

Forward-Looking Statements:

Statements in this press release that are not strictly historical in nature constitute "forward-looking statements." Such statements include, but are not limited to, references to the goals and potential results of the Metabasis-Roche collaboration, including the payments potentially receivable by Metabasis in connection with the collaboration, the potential benefits of and interest in Metabasis' HepDirect technology, and Metabasis' other business development initiatives. Such forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause Metabasis' actual results to be materially different from historical results or from any results expressed or implied by such forward-looking statements. These factors include, but are not limited to, risks and uncertainties related to Metabasis' dependence on Roche for the clinical development and registration of any product candidates that result from the collaboration, among other things; the progress and timing of clinical trials for Metabasis' product candidates; the fact that positive results from clinical trials does not necessarily mean later clinical trials will succeed; serious adverse side effects of, or serious adverse events related to, Metabasis' product candidates or proprietary technologies; difficulties or delays in development, testing, obtaining regulatory approval, producing and marketing Metabasis' product candidates; the potential and progress of preclinical compounds and programs; and other factors discussed in the "Risk Factors" section of Metabasis' Quarterly Report on Form 10-Q for the quarter ended March 31, 2008. All forward-looking statements are qualified in their entirety by this cautionary statement. Metabasis is providing this information as of this date of this release and does not undertake any obligation to update any forward-looking statements contained in this release as a result of new information, future events or otherwise.