Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 133,958	$ 20,525
Short-term investments	69,000	205,912
Prepaid expenses and other current assets	1,456	1,253
Total current assets	204,414	227,690
Right-of-use asset	661	948
Other assets	1,978	1,995
Total assets	207,053	230,633
Current liabilities:
Accounts payable	829	788
Accrued expenses	5,179	7,690
Current portion of operating lease liabilities	590	582
Total current liabilities	6,598	9,060
Long term portion of operating lease liabilities	53	357
Total liabilities	6,651	9,417
Commitments
Stockholders' equity:
Common stock, $0.001 par value per share, 150,000,000 shares authorized; 28,025,844 and 27,501,340 shares issued and outstanding at June 30, 2023 and December 31, 2022, respectively	28	28
Additional paid-in capital	636,447	632,512
Accumulated other comprehensive loss		(79)
Accumulated deficit	(531,397)	(507,643)
Total stockholders' equity	200,402	221,216
Total liabilities and stockholders' equity	207,053	230,633
Preferred stock
Stockholders' equity:
Preferred stock, $0.001 par value per share, 4,908,620 shares authorized and no shares issued and outstanding
Series X redeemable convertible preferred stock
Stockholders' equity:
Preferred stock, $0.001 par value per share, 4,908,620 shares authorized and no shares issued and outstanding	$ 95,324	$ 96,398

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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1