Property, Equipment and Software

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property, equipment and software consists of the following (in thousands):



	December 31,
	2017			2016
Computer equipment	$	2,261		$	2,520
Software	5,111			2,352
Furniture and office equipment	656			897
Lab equipment	20,549			20,208
Leasehold improvements	17,525			17,807
Construction in progress	32,800			—
Property, equipment and software	78,902			43,784
Less accumulated depreciation and amortization	(28,919		)	(25,823		)
Property, equipment and software, net	$	49,983		$	17,961

Construction in progress at December 31, 2017 consists of the costs incurred for the build-out of a manufacturing suite at our headquarters building in Rockville, Maryland, which is expected to be completed in mid-2018.

We had $9.6 million in property, equipment and software at December 31, 2017 that was purchased in 2017 but was not paid for by year end. Property, equipment and software balance at December 31, 2016 includes approximately $0.3 million in assets that were purchased in 2016 but were not paid for by year end. Depreciation and amortization expense related to property, equipment and software for the years ended December 31, 2017, 2016 and 2015 was $7.0 million, $6.8 million and $3.2 million, respectively.