CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 27,879	$ 2,563
Prepaid expenses and other current assets	960	717
Total current assets	28,839	3,280
Property and equipment, net	305	394
Long-term restricted cash	204	204
Goodwill	3,577	10,845
Total assets	32,925	14,723
Current liabilities:
Accounts payable	1,159	1,183
Accrued expenses	1,265	1,696
Deferred revenue	9,304	0
Total current liabilities	11,728	2,879
Deferred revenue, net of current portion	6,471	0
Total liabilities	18,199	2,879
Commitments (Note 12)
Stockholders' equity:
Preferred stock, $0.0001 par value—500,000 authorized and 0 issued and outstanding at September 30, 2019 and December 31, 2018
Common stock, $0.0001 par value—200,000,000 shares authorized; 19,994,560, and 4,932,723 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively.	2
Additional paid-in capital	225,844	206,409
Accumulated deficit	(211,120)	(194,565)
Total stockholders' equity	14,726	11,844
Total liabilities and stockholders' equity	$ 32,925	$ 14,723

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).