Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 52,218	$ 60,813
Restricted cash	792	0
Short-term investments	13,973	14,501
Accounts receivable	288	321
Prepaid expenses and other current assets	1,719	2,035
Total current assets	68,990	77,670
Property and equipment, net	936	1,044
Other assets	321	321
Total assets	70,247	79,035
Current liabilities:
Accounts payable	2,999	2,590
Accrued liabilities	4,516	4,257
Accrued compensation and benefits	1,921	2,571
Current portion of term loan	2,083	2,667
Total current liabilities	11,519	12,085
Term loan, less debt issuance costs	7,809	7,206
Total liabilities	19,328	19,291
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued or outstanding at March 31, 2018 and December 31, 2017, respectively	0	0
Common stock, $0.0001 par value; 200,000,000 shares authorized at March 31, 2018 and December 31, 2017; 21,395,077 and 21,389,736 shares issued and outstanding, respectively, at March 31, 2018; 20,534,993 and 20,525,688 shares issued and outstanding, respectively, at December 31, 2017	2	2
Additional paid-in capital	217,073	209,140
Accumulated other comprehensive loss	(18)	(8)
Accumulated deficit	(166,138)	(149,390)
Total stockholders' equity	50,919	59,744
Total liabilities and stockholders' equity	$ 70,247	$ 79,035

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

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.