Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021
Current assets
Cash and cash equivalents	$ 31,650	$ 35,936
Short-term investments	27,302	27,351
Accounts receivable	206	5
Inventory, net:
Raw materials	1,348	1,056
Work-in-process	80	147
Finished goods	267	297
Prepaid expenses and other current assets	164	318
Total current assets	61,017	65,110
Property and equipment, net	343	263
Operating leases, right-of-use assets, net	228	249
Other assets	11	11
Total assets	61,599	65,633
Current liabilities
Accounts payable	114	396
Payroll related accruals	517	344
Accrued expenses and other liabilities	688	888
Income tax payable	2	2
Term note payable - related party	500	2,500
Lease liabilities	100	81
Total current liabilities	1,921	4,211
Lease liabilities, net of current portion	189	215
Total liabilities	2,110	4,426
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock, $0.001 par value, 50,000,000 shares authorized; 49,450,558 shares issued and outstanding at September 30, 2021 and June 30, 2021	190,641	190,641
Additional paid-in capital	78,330	77,971
Accumulated deficit	(209,411)	(207,382)
Accumulated other comprehensive loss	(71)	(23)
Total stockholders’ equity	59,489	61,207
Total liabilities and stockholders’ equity	61,599	65,633
Convertible Preferred Stock
Stockholders’ equity
Convertible preferred stock, $0.001 par value, 2,500,000 shares authorized; 280,898 shares of Series D issued and outstanding at September 30, 2021 and June 30, 2021