Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Jun. 30, 2021
Current assets
Cash and cash equivalents	$ 30,170	$ 35,936
Short-term investments	27,106	27,351
Accounts receivable	92	5
Inventory, net:
Raw materials	1,135	1,056
Work-in-process	2	147
Finished goods	277	297
Prepaid expenses and other current assets	516	318
Total current assets	59,298	65,110
Property and equipment, net	870	263
Operating leases, right-of-use assets, net	206	249
Other assets	11	11
Total assets	60,385	65,633
Current liabilities
Accounts payable	90	396
Payroll related accruals	741	344
Accrued expenses and other liabilities	853	888
Income tax payable	2	2
Term note payable - related party	500	2,500
Lease liabilities, current	227	81
Total current liabilities	2,413	4,211
Lease liabilities, net of current portion	421	215
Total liabilities	2,834	4,426
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock, $0.001 par value, 250,000,000 and 50,000,000 shares authorized at December 31, 2021 and June 30, 2021, respectively; 49,514,467 and 49,450,558 shares issued and outstanding at December 31, 2021 and June 30, 2021, respectively	190,641	190,641
Additional paid-in capital	78,769	77,971
Accumulated deficit	(211,591)	(207,382)
Accumulated other comprehensive loss	(268)	(23)
Total stockholders’ equity	57,551	61,207
Total liabilities and stockholders’ equity	60,385	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 December 31, 2021 and June 30, 2021