CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 21,124	$ 25,764
Unbilled revenue receivable	5	13
Receivable from related party	21	17
Prepaid expenses and other assets	1,897	1,844
Total current assets	23,047	27,638
Property and equipment, net	1,275	1,317
Other noncurrent assets	32	32
Total assets	24,354	28,987
Current liabilities:
Current portion of long-term debt	776	0
Accounts payable	974	1,049
Accrued expenses and other current liabilities	1,265	1,273
Current portion of deferred revenue	0	1,034
Total current liabilities	3,015	3,356
Long-term debt, net	4,103	4,855
Common stock warrant liability	651	523
Other noncurrent liabilities	277	278
Total liabilities	8,046	9,012
Stockholders’ equity:
Common stock, $0.0001 par value per share; 200,000,000 shares authorized, 39,454,821 issued and outstanding, March 31, 2018; 39,300,823 shares issued and outstanding, December 31, 2017	4	4
Additional paid-in capital	54,394	53,586
Accumulated deficit	(38,090)	(33,615)
Total stockholders' equity	16,308	19,975
Total liabilities and stockholders’ equity	$ 24,354	$ 28,987

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).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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).