Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating activities
Net loss	$ (90,986,000)	$ (93,524,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	11,737,000	11,477,000
Depreciation expense	1,537,000	1,678,000
Non-cash interest expense	188,000	218,000
Non-cash lease expense	2,175,000	1,368,000
Loss on extinguishment of debt	0	3,226,000
Loss on disposal of property and equipment	232,000	5,000
Net foreign currency losses	1,012,000	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(799,000)	(63,000)
Accounts payable	(40,000)	1,075,000
Accrued expenses and other current liabilities	(814,000)	(404,000)
Operating lease liabilities	(2,287,000)	(1,414,000)
Deferred revenue	0	7,500,000
Other liabilities	0	(21,000)
Net cash used in operating activities	(78,045,000)	(68,879,000)
Investing activities
Purchases of property and equipment	(394,000)	(1,962,000)
Proceeds from sale of fixed assets	0	6,000
Net cash used in investing activities	(394,000)	(1,956,000)
Financing activities
Proceeds from issuance of common stock, net of issuance cost	79,682,000	81,961,000
Proceeds from the issuance of common stock under employee stock purchase plan and exercise of stock options	234,000	927,000
Proceeds from the issuance of long-term debt, net of issuance costs	0	14,778,000
Net cash provided by financing activities	79,916,000	97,666,000
Effect of exchange rate changes on cash and cash equivalents	(1,022,000)	0
Net increase in cash, cash equivalents and restricted cash	455,000	26,831,000
Cash, cash equivalents and restricted cash – beginning of period	69,754,000	70,420,000
Cash, cash equivalents and restricted cash – end of period	70,209,000	97,251,000
Supplemental disclosure of cash flow information
Cash paid for interest	2,963,000	2,383,000
Cash paid for taxes	592,000	9,000
Noncash investing and financing activities
Property and equipment additions included in accrued expenses	128,000	198,000
Issuance of common stock warrants	$ 0	$ 1,750,000