4. Balance Sheet Components

Cash Equivalents and Available-for-sale Securities

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


	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


	December 31, 2015
	Amortized		Gross Unrealized
	Cost		Gains		Losses			Fair Value
Money market funds	$	2,136	$	—	$	—		$	2,136
Corporate bonds		7,373		—		(5	)		7,368
Commercial paper		500		—		—			500

Total cash equivalents and available-for-sale securities	$	10,009	$	—	$	(5	)	$	10,004

Classified as:
Cash equivalents								$	2,136
Available-for-sale securities - current									7,868

Total cash equivalents and available-for-sale securities								$	10,004

All available-for-sale securities - current held as of December 31, 2016 and December 31, 2015 had contractual maturities of less than one year. All available securities – noncurrent held as of December 31, 2016 had contractual maturities of greater than one year but less than two years. There have been no material realized gains or losses on available-for-sale securities for the periods presented.

Prepaid Expenses and Other Current Assets

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


	December 31,
	2016		2015
Prepaid clinical and research related expenses	$	2,488	$	1,253
Other		906		305

Prepaid expenses and other current assets	$	3,394	$	1,558

Property and Equipment, Net

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


	December 31,
	2016			2015
Laboratory equipment	$	1,650		$	1,452
Furniture and computer equipment		163			140
Leasehold improvements		62			48

Total property and equipment		1,875			1,640
Less: accumulated depreciation and amortization		(1,313	)		(1,031	)

Property and equipment, net	$	562		$	609

Depreciation expense for the years ended December 31, 2016, 2015 and 2014 was $317,000, $247,000 and $258,000, respectively. As of December 31, 2016 and 2015, $8,000 and $51,000, respectively, property and equipment, net, were located in Australia. The remainder of the assets are located in the United States.

Accrued Expenses and Other Payables

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


	December 31,
	2016		2015
Accrued clinical and research related expenses	$	3,617	$	976
Accrued employee related expenses		1,420		754
Other		235		149

Total accrued expenses and other payables	$	5,272	$	1,879