Gilead Sciences, Inc. and Arresto Biosciences, Inc., a privately-held, development-stage biotechnology company focused on medicines to treat fibrotic diseases and cancer, announced the signing of a definitive agreement pursuant to which Gilead will acquire Arresto.

Under the terms of the agreement, Gilead will acquire Arresto for $225 million and potential future payments based on achievement of certain sales levels. Gilead anticipates that the deal would close in the first quarter of 2011, subject to satisfaction of certain closing conditions, and plans to finance the acquisition through available cash on hand.

Arresto develops medicines that target enzymes involved in the synthesis of the extracellular matrix, which appear to play a role in the etiology of a variety of fibrotic diseases and cancer. The company's lead product is AB0024, a humanized monoclonal antibody (mAb) targeting the human lysyl oxidase-like-2 (LOXL2) protein. The company recently initiated a Phase I study evaluating AB0024 in patients with idiopathic pulmonary fibrosis (IPF). A phase I study of AB0024 in patients with advanced solid tumours is also ongoing.

"Arresto's research and development expertise is well aligned with Gilead's areas of focus, including our ongoing clinical programme for ambrisentan in IPF," said Norbert W. Bischofberger, PhD, Gilead's executive vice president, research and development and chief scientific officer. "We look forward to working with the team from Arresto to advance the development of novel therapies for serious fibrotic diseases and explore their potential for the treatment of tumours."

"Gilead shares Arresto's vision of bringing innovative new therapeutic options to patients with unmet medical needs," said Peter Van Vlasselaer, PhD, Arresto's president and chief executive officer. "Arresto was founded based on the promise of selective antibody therapies and I am confident the combined resources of our companies best position us to build upon our early scientific results."

"Under Peter's direction, Arresto has accomplished a remarkable amount in three short years," said Beth Seidenberg, MD, Arresto chairman of the board, and Partner at Kleiner Perkins Caufield & Byers. "Peter's leadership is extraordinary and proven in several companies. The board is proud of the accomplishment of the Arresto team and enthusiastic about Gilead's commitment to advancing the programs for the treatment of patients with fibrosis and cancer."

Arresto Biosciences is a biotechnology company that develops medicines to treat fibrotic diseases and cancer by targeting enzymes involved in the synthesis of the extracellular matrix. In addition to AB0024, the company has preclinical candidates targeting proteins associated with various inflammatory diseases.

Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes innovative therapeutics in areas of unmet medical need. The company's mission is to advance the care of patients suffering from life-threatening diseases worldwide.