
19.	Collaborations

In April 2011, we agreed to terminate our collaboration with Vernalis plc. (Vernalis) for the development and commercialization of an adenosine A2a receptor antagonist for treatment of Parkinson’s disease effective April 11, 2011. Under the terms of the agreement, we will return the program to Vernalis and have no further license to, or continuing involvement in the development of, this compound and its related intellectual property. In exchange, we will receive a royalty on future net sales if this compound is ultimately commercialized. We funded development costs through the termination date and have no other remaining development obligations after that date. Development expense incurred by this collaboration in 2011 was insignificant.