Property and equipment, net

12 Months Ended

Dec. 31, 2016

Property Plant And Equipment [Abstract]

Property and equipment, net

5. Property and equipment, net

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

	December 31,
	2016			2015
Computer equipment and software	$	1,655		$	1,259
Office equipment		1,427			1,104
Laboratory equipment		16,305			10,520
Leasehold improvements		13,697			11,010
Construction-in-progress		136,315			65,542
Total property and equipment		169,399			89,435
Less accumulated depreciation and amortization		(12,444	)		(6,821	)
Property and equipment, net	$	156,955		$	82,614

Depreciation and amortization expense related to property and equipment was $5.9million, $3.7 million, and $2.3 million for the years ended December 31, 2016, 2015, and 2014, respectively.  Construction-in-progress as of December 31, 2016 includes $126.9million related to the construction of 60 Binney Street in Cambridge, Massachusetts, of which $120.1 million was incurred by the landlord. Please refer to Note 8, “Commitments and contingencies,” for further information.