CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 67,670	$ 62,294
Short-term investments	134,114	230,165
Prepaid expenses and other current assets	8,130	9,945
Total current assets	209,914	302,404
Property and equipment, net	3,289	3,671
Right-of-use asset	1,871	2,045
Restricted cash	403	403
Total assets	215,477	308,523
Current liabilities:
Accounts payable	3,793	10,415
Accrued expenses and other current liabilities	11,536	13,530
Lease liability	519	472
Total current liabilities	15,848	24,417
Long-term liabilities:
Lease liability	2,692	3,086
Total liabilities	18,540	27,503
Commitments and contingencies
Stockholders' equity:
Preferred Stock, $0.001 par value: 10,000,000 shares authorized; no shares issued and outstanding at June 30, 2020 and December 31, 2019
Common stock, $0.001 par value: 120,000,000 shares authorized; 44,115,612 and 43,996,753 shares issued and outstanding at June 30, 2020 and December 31, 2019, respectively	44	44
Additional paid-in capital	621,085	606,307
Accumulated other comprehensive income	238
Accumulated deficit	(424,430)	(325,331)
Total stockholders' equity	196,937	281,020
Total liabilities and stockholders' equity	$ 215,477	$ 308,523

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).