Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 23,621	$ 7,042
Marketable securities	93,641	100,986
Prepaid expenses	3,998	1,491
Other current assets	21	15
Total current assets	121,281	109,534
Restricted cash	245	84
Property and equipment, net	437	321
Total assets	121,963	109,939
Current liabilities:
Accounts payable	9,973	2,989
Accrued liabilities	2,220	2,727
Total current liabilities	12,193	5,716
Other liabilities	6	19
Total liabilities	12,199	5,735
Commitments and contingencies (Note 10)
Stockholders’ equity:
Common stock, $0.0001 par value, 150,000,000 shares authorized as of September 30, 2019 and December 31, 2018; 36,443,631 and 28,055,344 shares issued and outstanding as of September 30, 2019 and December 31, 2018, respectively; 36,443,631 and 28,054,344 shares vested as of September 30, 2019 and December 31, 2018, respectively	4	3
Additional paid-in capital	234,893	175,635
Accumulated deficit	(125,242)	(71,393)
Accumulated other comprehensive gain (loss)	109	(41)
Total stockholders’ equity	109,764	104,204
Total liabilities and stockholders’ equity	$ 121,963	$ 109,939

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).