Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
CURRENT ASSETS:
Cash and cash equivalents	$ 2,374	$ 10,266
Marketable securities	16,836	12,012
Accounts receivable, net	27	11
Inventories, net	232	176
Prepaid and other current assets	943	2,706
Total current assets	20,412	25,171
Right-of-use assets	549	652
Property and equipment, net	549	605
Other noncurrent assets	592	692
Total assets	22,102	27,120
CURRENT LIABILITIES:
Accounts payable	5,473	3,598
Accrued expenses and other current liabilities	3,117	7,709
Convertible note, current	1,997	0
Total current liabilities	10,587	11,307
Operating lease liabilities, noncurrent	361	479
Convertible note, noncurrent	146	146
Other noncurrent liabilities	826	64
Total liabilities	11,920	11,996
COMMITMENTS AND CONTINGENCIES (Note 17)
STOCKHOLDERS’ EQUITY:
Preferred stock—$0.0001 par value: 1,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock—$0.0001 par value: 600,000,000 shares authorized; 20,550,266 and 13,734,160 shares issued and outstanding at June 30, 2025 and December 31, 2024	2	1
Additional paid-in capital	400,561	388,213
Accumulated other comprehensive income	0	5
Accumulated deficit	(390,381)	(373,095)
Total stockholders’ equity	10,182	15,124
Total liabilities and stockholders’ equity	$ 22,102	$ 27,120