Balance Sheet Components

12 Months Ended

Dec. 31, 2019

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,
	2019			2018
	(in thousands)
Computer hardware and software	$	2,830		$	2,148
Furniture and equipment		1,828			1,002
Leasehold improvements		8,967			4,709
		13,625			7,859
Less: Accumulated depreciation		(4,499	)		(2,216	)
	$	9,126		$	5,643

Depreciation expense for the years ended December 31, 2019, 2018 and 2017 was $2.3 million, $1.1 million and $0.5 million, respectively.

The useful life for computer hardware and software is three years, furniture and equipment is five 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,
	2019		2018
	(in thousands)
Accrued research and development costs	$	46,940	$	21,216
Employee-related expenses		22,011		19,638
Professional services		16,720		10,903
Other		947		237
	$	86,618	$	51,994