13. RESTRUCTURING

In November 2012, the Company notified 21 Bothell, Washington based employees that they would be terminated as part of the corporate headquarters relocation to Cambridge, Massachusetts. The employees were given various incentives to remain through a transition period which was completed in 2013. During the first quarter of 2014, the transition period was extended to the end of the second quarter of 2014 for one employee. For the three months ended March 31, 2014, the Company recorded a restructuring charge of less than $0.1 million to research and development expenses. For the three months ended March 31, 2013, the Company recorded a restructuring charge of $0.3 million to research and development expenses and $0.2 million to general and administrative expenses.

Changes in the liability and the balance related to the restructuring plan are as follows:


	For the Three Months Ended March 31,
	2014			2013
	(in thousands)
Balance at beginning of the period	$	44		$	185
Restructuring charges		9			462
Payments		(8	)		(201	)

Balance at end of the period	$	45		$	446