Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Operating activities
Net loss	$ (77,331)	$ (73,790)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,982	1,927
Stock-based compensation	12,945	16,946
Non-cash operating lease expense	700	660
Impairment of in-process research and development intangible asset	20,964	0
Accretion of discount on marketable debt securities	(6,109)	(4,788)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(203)	2,532
Accounts payable	1,200	(3,507)
Accrued expenses and other current liabilities	(1,670)	(14,097)
Operating lease liabilities	(1,231)	2,410
Deferred revenues	(7,660)	998
Deferred tax liabilities	(2,164)
Other	(95)
Net cash used in operating activities	(57,672)	(70,709)
Investing activities
Cash acquired in acquisition of Apexigen, Inc.		6,660
Redemption of marketable debt securities	168,510	92,048
Purchase of marketable debt securities	(160,118)	(196,831)
Purchase of property and equipment	(237)	(6,726)
Net cash provided by (used in) investing activities	8,155	(104,849)
Financing activities
Proceeds from issuance of common stock and pre-funded warrants in private placement, net of offering costs	46,872
Proceeds from issuance of common stock pursuant to ATM program, net of offering costs	12,174	6,122
Tax withholding payments related to net settlement of restricted common stock	(240)	(445)
Proceeds from the exercise of stock options	296	120
Proceeds from issuance of common stock under ESPP	224	132
Net cash provided by financing activities	59,326	5,929
Net increase (decrease) in cash, cash equivalents and restricted cash	9,809	(169,629)
Cash, cash equivalents and restricted cash at beginning of year	11,136	180,765
Cash, cash equivalents and restricted cash at end of year	20,945	11,136
Supplemental cash flow information:
Cash paid for interest	10	1
Cash paid for income taxes, net of refunds received	164	48
Noncash investing and financing activities
ROU asset in exchange for financing lease liability	265
Shares, warrants, and replacement stock options and restricted stock units issued for acquisition of Apexigen, Inc.		10,732
Property and equipment in accounts payable and accrued expenses		237
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	19,473	9,664
Restricted cash	1,472	1,472
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 20,945	11,136
Pfizer License Agreement
Noncash investing and financing activities
Issuance of common stock to Pfizer Inc.		$ 5,000