Under the above license agreements we are obligated to make potential milestone payments as listed in the following table. These obligations are contingent upon achieving the applicable milestone event, the timing of which cannot presently be determined.



Licensor		Aggregate potential milestone payments
Drexel University		$1 million per licensed product

Lankenau Institute for Medical Research under the IDO-1 Agreement (1)		$1.36 million per licensed product

Lankenau Institute for Medical Research under the LIMR IDO-2 Agreement (1)		$1.52 million per licensed product, subject to reductions if milestones also qualify under the IDO-1 Agreement

Lankenau Institute for Medical Research under the 2009 LIMR Agreement (1)		$610,000 per licensed product, subject to reductions if milestones also qualify under the IDO-1 Agreement or LIMR IDO-2 Agreement

Georgia Health Sciences University		$2.8 million per licensed product

Regents of the University of California		$285,000 per licensed product

Her Majesty the Queen in Right of Canada		C$205,000 per licensed product

We have made payments of approximately $255,000, $89,000, $391,000, and $2.8 million under all of the in-licensing agreements for the years ended December 31, 2012, 2011, 2010, and from inception, respectively, which is recorded as a component of general and administrative expenses.