Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 22,465	$ 46,345
Short-term investments	147,561	92,012
Accounts receivable, net	1,010	28
Inventory	381	0
Prepaid expenses and other current assets	5,130	2,481
Total current assets	176,547	140,866
Property and equipment, net of accumulated depreciation and amortization of $4,538 and $3,984, respectively	1,987	2,071
Goodwill	44,543	44,543
Operating lease right-of-use-assets	5,524	6,407
Other assets	828	412
Total assets	229,429	194,299
Current liabilities:
Accounts payable	14,389	10,395
Accrued liabilities	17,157	12,777
Total current liabilities	31,546	23,172
Long-term debt, net	99,508	48,579
Long-term operating lease liabilities	5,265	5,424
Total liabilities	136,319	77,175
Commitments and contingencies (Note 10)
Stockholders' Equity:
Preferred stock, $0.01 par value; 5,000,000 shares authorized; no shares issued and outstanding	$ 0	$ 0
Common stock, shares authorized	300,000,000	300,000,000
Common stock, $0.001 par value; 300,000,000 shares authorized; 245,792,668 and 189,213,948 shares issued, respectively	$ 245	$ 189
Additional paid-in capital	1,862,558	1,709,144
Accumulated deficit	(1,766,839)	(1,589,720)
Accumulated other comprehensive income (loss)	31	(428)
Treasury stock, at cost, 867,973 and 488,205 shares, respectively	(2,885)	(2,061)
Total stockholders' equity	93,110	117,124
Total liabilities and stockholders’ equity	$ 229,429	$ 194,299