Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 20,111	$ 25,229
Short-term investments	6,160	26,494
Accounts receivable	4,281	5,761
Unbilled receivable from government contracts	36,781	6,208
Prepaid expenses and other current assets	3,046	4,568
Total current assets	70,379	68,260
Property and equipment, net	6,926	8,705
Prepaid clinical services, long-term	60,116	60,116
Right-of-use assets, net	18,137	20,404
Intangible assets, net	3,192	3,557
Goodwill	4,508	4,508
Other long-term assets	827	839
Total assets	164,085	166,389
Current liabilities:
Accounts payable	10,611	6,963
Other accrued current liabilities	35,727	11,378
Current portion of operating lease liability	3,486	3,077
Current portion of liability related to sale of future royalties	2,677	4,060
Total current liabilities	117,878	90,878
Operating lease liability, net of current portion	12,627	14,449
Liability related to sale of future royalties, net of current portion	230	1,698
Other long-term liabilities	472	439
Total liabilities	131,207	107,464
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock: $0.0001 par value; 5,000,000 shares authorized; none issued and outstanding as of June 30, 2025 and December 31, 2024	0	0
Common stock: $0.0001 par value; 350,000,000 shares authorized as of June 30, 2025 and December 31, 2024; 229,417,137 shares issued and 228,912,563 shares outstanding as of June 30, 2025 and 228,203,822 shares issued and 227,774,275 shares outstanding as of December 31, 2024	23	23
Additional paid-in capital	540,328	535,770
Treasury stock at cost, 504,574 shares as of June 30, 2025 and 429,547 shares as of December 31, 2024	(367)	(350)
Accumulated deficit	(507,099)	(476,522)
Accumulated other comprehensive income (loss)	(7)	4
Total stockholders’ equity	32,878	58,925
Total liabilities and stockholders’ equity	164,085	166,389
Government Contract [Member]
Current liabilities:
Deferred government revenue	$ 65,377	$ 65,400

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, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2