CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities
Net loss	$ (30,299)	$ (41,183)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization		86
Non-cash lease expense	80	461
Non-cash gain on lease termination	(5,583)
Accretion of short-term investment discounts	(745)	(729)
Stock-based compensation expense	5,034	10,029
Changes in operating assets and liabilities:
Interest receivable	26	(87)
Prepaid expenses and other current assets and prepaid expenses to related party	2,715	(333)
Other assets	122	122
Income tax payable		2
Accounts payable, accrued expenses, other liabilities and amount due to related party	(15,730)	(486)
Net cash used in operating activities	(44,380)	(32,118)
Cash flows from investing activities
Purchase of short-term investments		(11,756)
Maturities of short-term investments	40,000	53,480
Net cash provided by (used in) investing activities	40,000	41,724
Cash flows from financing activities
Net (decrease) increase in cash, cash equivalents, and restricted cash	(4,380)	9,606
Cash, cash equivalents, and restricted cash at beginning of period	90,973	106,944
Cash, cash equivalents, and restricted cash at end of period	86,593	116,550
Non-cash investing and financing activities
Unrealized gain (loss) on available-for-sale securities	(76)	167
Supplemental disclosure of cash flows
Cash and cash equivalents	86,039	115,698
Restricted cash	554	852
Total cash, cash equivalents, and restricted cash	$ 86,593	$ 116,550