Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 71,504	$ 59,321
Restricted cash	562	560
Marketable securities	132,679	177,140
Accounts receivable, net	20,750	16,758
Inventory	5,646	6,210
Prepaid expenses	12,372	13,842
Other current assets	2,651	1,202
Total current assets	246,164	275,033
Property and equipment, net	3,570	4,003
Intangible assets	7,182	7,382
Right of use assets - operating leases	7,450
Other assets	501	544
Total assets	264,867	286,962
Current liabilities:
Accounts payable	9,880	4,226
Accrued expenses and other current liabilities	35,632	42,203
Operating lease liability, current	2,168
Total current liabilities	47,680	46,429
Other non-current liabilities	71	95
Notes payable	183,556	179,806
Operating lease liability, long term	5,556
Total liabilities	236,863	226,330
Commitments and contingencies
Stockholders’ equity:
Common stock, $.0001 par value; 200,000,000 shares authorized, 45,967,080 shares and 45,563,693 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	5	5
Additional paid-in-capital	1,174,661	1,165,003
Accumulated other comprehensive loss	(281)	(755)
Accumulated deficit	(1,146,381)	(1,103,621)
Total stockholders’ equity	28,004	60,632
Total liabilities and stockholders’ equity	$ 264,867	$ 286,962