Condensed consolidated balance sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 129,596	$ 143,093
Other current assets	1,401	503
Total current assets	130,997	143,596
Property and equipment, net	3,090	2,060
Operating lease right-of-use assets	9,646	770
Intangible asset, net	458	567
Other non-current assets	1,133	30
Total assets	145,324	147,023
Current liabilities
Accounts payable and accrued liabilities	6,014	4,125
Operating lease liabilities	212	556
Finance lease liabilities	94	62
Total current liabilities	6,320	4,743
Non-current operating lease liabilities	10,197	447
Non-current finance lease liabilities	108	146
Total liabilities	16,625	5,336
Stockholders’ equity
Preferred stock - $0.000001 par value - authorized, 5,000,000 as of June 30, 2020 and December 31, 2019; nil issued and outstanding as of June 30, 2020 and December 31, 2019.
Additional paid-in capital	446,616	441,216
Accumulated deficit	(317,917)	(299,529)
Total stockholders’ equity	128,699	141,687
Total liabilities and stockholders’ equity	$ 145,324	$ 147,023

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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

- Definition

Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (g)(2)
-URI http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30)(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682