Gilead Sciences, Inc. and Nimbus Therapeutics, LLC announced that the companies have signed a definitive agreement under which Gilead will acquire Nimbus Apollo, Inc., a wholly-owned subsidiary of Nimbus Therapeutics, and its Acetyl-CoA Carboxylase (ACC) inhibitor programme. Nimbus Therapeutics will receive an upfront payment of $400 million, with the potential to receive an additional $800 million in development-related milestones over time.

The Nimbus Apollo programme includes the lead candidate NDI-010976, an ACC inhibitor, and other preclinical ACC inhibitors for the treatment of non-alcoholic steatohepatitis (NASH), and for the potential treatment of hepatocellular carcinoma (HCC) and other diseases. NDI-010976 was granted Fast Track designation by the US Food and Drug Administration (FDA) in February 2016 and phase 1 data for the compound will be presented next month during an oral session at The International Liver Congress 2016, the annual meeting of the European Association for the Study of the Liver (EASL).

NASH is a serious liver disease resulting from metabolic dysfunction associated with steatosis (fat within the liver) that can lead to inflammation, hepatocellular injury, progressive fibrosis and cirrhosis. Affecting up to 15 million people in the United States, NASH is expected to become the leading indication for liver transplantation by 2020. ACC inhibitors target a central cause of the disease - reducing aberrant lipid-derived signaling that can result in steatosis, inflammation and fibrosis.

"The acquisition of Nimbus' ACC-inhibitor programme represents a timely and important opportunity to accelerate Gilead's ongoing efforts to address unmet needs in NASH," said Norbert Bischofberger, PhD, executive vice president, research and development and chief scientific officer, Gilead Sciences. "These molecules will complement and further strengthen Gilead's pipeline and capabilities to advance a broad clinical programme in NASH that includes compounds targeting multiple key pathways involved in the pathogenesis of the disease."

"Given the company's long-standing commitment to and expertise in liver disease, we are confident that Gilead is the ideal partner to accelerate and maximize the potential of the ACC inhibitor program," said Don Nicholson, PhD, chief executive officer of Nimbus Therapeutics. "This agreement underscores Nimbus' ability to rapidly discover, design and optimize promising therapeutics in areas of unmet need, an approach we will continue to apply against other medically important targets."

Upon completion of the acquisition, Nimbus Apollo will become a wholly-owned subsidiary of Gilead. Nimbus Therapeutics will retain ownership of its other research and development subsidiaries. Gilead will be solely responsible for future development and commercialisation of NDI-010976 and other ACC inhibitors.

Acetyl-CoA carboxylase (ACC) is an enzyme with two isoforms (ACC1 and ACC2) that is involved in de novo lipogenesis (the synthesis of endogenous fatty acids) and the regulation of beta-oxidation (the process by which fatty acids are broken down at a cellular level). Inhibitors of ACC therefore have the potential to prevent production of new lipids within the liver and stimulate their breakdown. In animal models of fatty liver, ACC inhibition reduces hepatic fat content, inflammation and fibrosis (scarring), all of which are important hallmarks of NASH progression. NDI-010976 is a potent, liver-targeted, allosteric inhibitor of both ACC isoforms.