Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2017

Balance Sheet Components

Schedule of cash equivalents and available-for-sale securities

Cash equivalents and available-for-sale securities consisted of the following (in thousands):

	December 31, 2017
	Amortized		Gross Unrealized
	Cost		Gains		Losses		Fair Value
Money market funds	$	48,704	$	—	$	—	$	48,704
Corporate bonds		6,254		—		(7)		6,247
Commercial paper		58,524		—		—		58,524
Government bonds		40,428		—		(125)		40,303
Total cash equivalents and available-for-sale securities	$	153,910	$	—	$	(132)	$	153,778
Classified as:
Cash equivalents							$	104,348
Available-for-sale securities - current								37,972
Available-for-sale securities - noncurrent								11,458
Total cash equivalents and available-for-sale securities							$	153,778

	December 31, 2016
	Amortized		Gross Unrealized
	Cost		Gains		Losses		Fair Value
Money market funds	$	11,270	$	—	$	—	$	11,270
Corporate bonds		21,886		—		(45)		21,841
Commercial paper		10,769		—		—		10,769
Government bonds		41,316		2		(29)		41,289
Total cash equivalents and available-for-sale securities	$	85,241	$	2	$	(74)	$	85,169
Classified as:
Cash equivalents							$	18,504
Available-for-sale securities - current								56,515
Available-for-sale securities - noncurrent								10,150
Total cash equivalents and available-for-sale securities							$	85,169

Summary of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):

	December 31,
	2017		2016
Prepaid clinical and research related expenses	$	2,324	$	2,488
Prepaid insurance		378		408
Other		1,071		498
Prepaid expenses and other current assets	$	3,773	$	3,394

Summary of Property and Equipment Net

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

	December 31,
	2017		2016
Laboratory equipment	$	2,177	$	1,650
Furniture and computer equipment		270		163
Leasehold improvements		26		62
Total property and equipment		2,473		1,875
Less: accumulated depreciation and amortization		(1,594)		(1,313)
Property and equipment, net	$	879	$	562

Summary of Accrued Expenses and Other Payables

Accrued expenses and other payables consisted of the following (in thousands):

	December 31,
	2017		2016
Accrued clinical and research related expenses	$	6,437	$	3,617
Accrued employee related expenses		2,718		1,420
Accrued professional service fees		267		115
Other		124		120
Accrued expenses and other payables	$	9,546	$	5,272