Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash flows from operating activities:
Net loss	$ (32,872)	$ (33,194)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	6,428	5,794
Amortization of premiums and discounts on short-term investments, net	(809)	(2,062)
Non-cash interest expense	58	58
Non-cash lease expense	230	231
Depreciation	99	81
Changes in operating assets and liabilities:
Accounts receivable	(432)	(1,814)
Inventory	328	(1,362)
Prepaid expenses and other current assets	2,427	845
Other non-current assets	253	275
Operating lease liabilities	(254)	(250)
Accounts payable and accrued liabilities	(4,266)	(6,670)
Net cash used in operating activities	(28,810)	(38,068)
Cash flows from investing activities:
Purchases of property and equipment	(1,280)	(2,058)
Purchase of short-term investments	(26,555)	(23,052)
Maturity of short-term investments	34,819	92,000
Net cash provided by investing activities	6,984	66,890
Cash flows from financing activities:
Issuance of common stock upon exercise of stock options	0	76
Proceeds from issuance of common stock under employee stock purchase plan	94	294
Deferred offering costs paid for financing	(17)	(49)
Net cash provided by financing activities	77	321
Net (decrease) increase in cash, cash equivalents and restricted cash	(21,749)	29,143
Cash, cash equivalents and restricted cash, beginning of year	62,952	39,083
Cash, cash equivalents and restricted cash, end of period	41,203	68,226
Supplemental disclosure of cash flow information:
Interest paid during the period	115	115
Supplemental disclosure of non-cash activities:
Accrued property and equipment	$ 591	$ 519