Balance Sheet Components

12 Months Ended

Dec. 31, 2017

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components

4. Balance Sheet Components

Property and Equipment, net

Property and equipment, net consists of the following:

	December 31,
	2017			2016
	(in thousands)
Computer hardware and software	$	1,090		$	708
Furniture and equipment		1,029			695
Leasehold improvements		2,967			527
		5,086			1,930
Less: Accumulated depreciation		(1,073	)		(542	)
	$	4,013		$	1,388

Depreciation expense for the years ended December 31, 2017, 2016 and 2015 was $0.5 million, $0.3 million and $0.1 million, respectively.

The useful life for computer hardware and software is 3 years, furniture and equipment is 5 years and leasehold improvements is the lesser of the useful life or the term of the respective lease.

Accrued Expenses

Accrued expenses consist of the following:

	December 31,
	2017		2016
	(in thousands)
Development costs	$	23,473	$	14,541
Employee-related expenses		15,838		5,948
Professional services		3,166		1,751
Other accrued expenses		124		112
	$	42,601	$	22,352