Existing Collaborations

In June 2006, we entered into a collaboration agreement with Procter & Gamble Pharmaceuticals for the development and commercialization of our product candidate ATI-7505. We retained the right to co-develop and co-promote the drug. Under the agreement, P&G paid us a $25.0 million nonrefundable upfront license fee and may owe up to an aggregate of approximately $391.0 million in development, product approval and sales based milestone payments over the remaining life of the agreement, of which approximately $216.0 million could be earned prior to commercialization. We are also entitled to receive royalties on sales and a share of certain payments which may be received by P&G.