Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents		$ 229,520	$ 163,030
Short term investments		0	18,311
Collaboration receivable - related party		7,559	0
Inventories		5,340	0
Prepaid expenses and other current assets		8,819	13,423
Total current assets		251,238	194,764
Property and equipment, net		24,026	22,985
Operating lease assets		110,283	110,984
Restricted cash		8,185	8,185
Restricted investments		1,401	1,401
Other non-current assets		11,254	10,465
Total assets		406,387	348,784
Current liabilities:
Accounts payable		12,922	17,440
Accrued expenses and other current liabilities	[1]	55,878	59,840
Operating lease liabilities		5,470	3,601
Short term portion of note payable, net of discount		0	456
Deferred income - related party		2,817	0
Deferred revenue - related party		811	4,259
Total current liabilities		77,898	85,596
Long term portion of note payable, net of discount		100,742	50,591
Operating lease liabilities, net of current portion		106,706	107,942
Deferred revenue, net of current portion - related party		94,927	92,430
Derivative Liability, Noncurrent		1,968	0
Other long-term liabilities		1,532	1,442
Total liabilities		383,773	338,001
Commitments and contingencies (Note 14)
Stockholders' equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized at June 30, 2023 and December 31, 2022; no shares issued and outstanding at June 30, 2023 and December 31, 2022		0	0
Common stock, $0.001 par value; 240,000,000 and 200,000,000 shares authorized at June 30, 2023 and December 31, 2022, respectively; 128,037,679 and 125,222,273 shares issued and outstanding at June 30, 2023 and December 31, 2022, respectively		128	125
Additional paid-in capital		911,620	875,181
Accumulated other comprehensive loss		(1)	(12)
Accumulated deficit		(889,133)	(864,511)
Total stockholders' equity		22,614	10,783
Total liabilities and stockholders' equity		$ 406,387	$ 348,784

[1] Includes related party amounts of $31,372 and $34,770 at June 30, 2023 and December 31, 2022, respectively (see Note 16)