August 14, 2009 - TET Systems Holding GmbH & Co. KG ("TET Systems"), a worldwide leader in controlled gene expression, today announced that TET Systems and Pharmasset, Inc. have settled patent litigation between the companies surrounding TET's patented gene expression technology.

As part of the confidential settlement, the parties agreed to dismiss the litigation with prejudice and Pharmasset agreed to take a license under TET Systems' portfolio of systems for efficient, precise, and reversible control over both timing and level of gene expression in eukaryotic cells. Under the terms of the agreement, Pharmasset will, among other things, make an undisclosed payment to TET Systems.

TET Systems was founded by Prof. Dr. H. Bujard and his colleagues. Today, TET Systems' technology is the most widely used method to control gene expression in higher organisms. 85% of the world's leading pharmaceutical companies license the TET technology and the broad usage of the TET Technology is demonstrated by more than 6,200 publications in peer-reviewed journals (June 2009).