Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 194,494	$ 31,569
Marketable securities	34,982	184,320
Prepaid expenses and other, current	6,998	7,660
Total current assets	236,474	223,549
Property and equipment, net	5,153	2,383
Prepaid expenses and other, long-term	6,846	9,597
Restricted cash	4,317	4,313
Total assets	252,790	239,842
Current liabilities:
Accounts payable	20,035	17,803
Accrued expenses	17,426	14,639
Total current liabilities	37,461	32,442
Deferred rent	5,505	1,393
Total liabilities	42,966	33,835
Commitments and contingencies (Note 9)
Stockholders' equity:
Common stock - $.0001 par value; 100,000,000 shares authorized; 36,826,010 issued and outstanding at December 31, 2016, and 32,466,842 issued and outstanding at December 31, 2015	4	3
Additional paid-in capital	1,006,344	726,651
Accumulated other comprehensive loss	(13)	(147)
Accumulated deficit	(796,511)	(520,500)
Total stockholders' equity	209,824	206,007
Total liabilities and stockholders' equity	$ 252,790	$ 239,842

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).