Note 11 - Income Taxes (Tables)

12 Months Ended

Jun. 30, 2023

Notes Tables

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended June 30,
(In thousands)	2023			2022
Expected benefit	$	2,025		$	1,749
State tax expense		—			—
Tax credits		200			166
Change in valuation allowance		(1,838	)		(1,511	)
Stock-based compensation		(296	)		(306	)
Prior year true-up		—			(9	)
Expiration of net operating loss carryovers		(88	)		(89	)
Other permanent items		(3	)		—
Total income tax benefit	$	—		$	—

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	Year Ended June 30,
(In thousands)	2023			2022
Deferred tax assets:
Net operating loss carryforwards	$	17,920		$	17,202
Tax credit carryforwards		1,530			1,330
Lease liability - current and non-current		128			113
Unrealized loss on securities		305			—
IRC Section 174 R&D Expense Capitalization		1,061
Accrued expenses and other timing		143			180
Stock-based compensation		111			579
Property and equipment, principally due to differences in depreciation		—			—
Total gross deferred tax assets	$	21,198		$	19,404
Less — valuation allowance		(21,064	)		(19,348	)
Net deferred tax assets	$	134		$	56
Deferred tax liabilities:
Right-of-use assets	$	(55	)	$	(34	)
Property and equipment, principally due to differences in depreciation		(79	)		(22	)
Total gross deferred tax liabilities		(134	)		(56	)
Net deferred tax assets	$	—		$	—

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	Year Ended June 30,
(In thousands)	2023		2022
Fiscal year beginning balance	$	400	$	329
Additions for tax positions of current period		86		71
Additions for tax positions of prior years		—		—
Decreases for tax positions of prior years		—		—
Fiscal year ending balance	$	486	$	400