Trius Therapeutics Initiates U.S. Phase I Trial for its Oxazolidinone Antibacterial Drug, TR-701

San Diego, CA, January 7, 2008 – Trius Therapeutics, Inc. announced today that it initiated its first Phase 1 clinical trial of TR-701, an antibacterial drug candidate intended for treatment of patients with serious Gram-positive bacterial infections, including those caused by MRSA and other drug-resistant strains. The eighty-eight subject single and multiple ascending dose trial will test tolerability, safety and pharmacokinetics of the oral dosage form of the drug and will compare its properties to those of Zyvox®, the only marketed drug in the oxazolidinone class.

"In this early clinical trial our goal is to demonstrate the potential of TR-701 to provide patients and clinicians with more convenient dosing and a broader safety margin than the current standard of care,” stated Jeffrey Stein, Ph.D., President and CEO of Trius Therapeutics. "TR-701’s potential for once-daily dosing, supported by results of prior exploratory human testing in Korea and preclinical animal data, is expected to translate into an increased therapeutic index and thereby provide an important option for the treatment of serious infections caused by drug-resistant bacterial pathogens.” properties to those of Zyvox®, the only marketed drug in the oxazolidinone class.

”Because the majority of bacterial infections in the hospital are now caused by bacteria resistant to many antibiotics, and such infections are also spreading alarmingly within the community, there is an ever growing need for potent yet safe orally available drugs to treat infections caused by resistant Gram-positive pathogens” stated Philippe Prokocimer, M.D., Chief Medical Officer of Trius. “We believe that TR-701 has the potential to become a first-line, best-in-class, treatment for infections caused by these pathogens.” properties to those of Zyvox®, the only marketed drug in the oxazolidinone class.

About Trius Therapeutics: Trius Therapeutics is discovering and developing innovative antibacterial drugs for the treatment of infections caused by resistant pathogens. The company’s lead product candidate, TR-701 is a novel oral and IV oxazolidinone antibiotic with potent activity against drug-resistant Gram-positive bacterial pathogens including those resistant to Zyvox®. The preclinical profile of TR-701 has been documented in a series of presentations at the recent ICAAC conference and can be accessed at the Trius website. Trius has licensed worldwide rights outside of Korea to TR-701 from Dong-A Pharmaceuticals. Trius’ pipeline includes three additional structure-based drug design programs directed against novel antibacterial targets. For more information, visit www.triusrx.com. properties to those of Zyvox®, the only marketed drug in the oxazolidinone class.