v3.24.0.1
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES      
Net loss $ (151,759) $ (112,033) $ (100,777)
Adjustments to reconcile net loss to net cash used in operating activities:      
Stock-based compensation expense 21,497 23,243 10,054
Depreciation 29 43 41
Non-cash lease expense 234 217 203
Net amortization of premiums and discounts on short-term investments (9,554) (12) 1,066
Amortization of debt issuance costs and discount 448 204  
Fair value change in warrant liability 79 264  
Write-off of deferred offering costs 337    
Unrealized foreign exchange gain and loss (8) 16 5
Changes in operating assets and liabilities:      
Prepaid expenses and other assets (6,740) 2,112 (2,101)
Accounts payable (645) 968 3,273
Accrued expenses and other current liabilities 946 (7,333) 8,737
Operating lease liability (231) (206) (182)
Net cash used in operating activities (145,367) (92,517) (79,681)
CASH FLOWS FROM INVESTING ACTIVITIES      
Purchase of short-term and long-term marketable securities (433,123) (101,446) (43,561)
Proceeds from maturities of short-term marketable securities 209,500 37,621 85,841
Net cash (used in) provided by investing activities (223,623) (63,825) 42,280
CASH FLOWS FROM FINANCING ACTIVITIES      
Proceeds from the exercise of stock options 3,267 5,016 750
Proceeds from the issuance of common stock pursuant to employee stock purchase plan purchases 396 280 373
Proceeds from the issuance of common in a follow-on public offering   216,200  
Proceeds from the issuance of common stock pursuant to the ATM offering 124,212    
Proceeds from the issuance of common stock pursuant to registered direct offering 211,217    
Proceeds from the issuance of common stock pursuant to private offering   25,000  
Proceeds from loan payable 15,000 10,000  
Payment of debt and equity issuance costs (776) (864) (521)
Net cash provided by financing activities 353,316 255,632 602
Net (decrease) increase in cash, cash equivalents and restricted cash (15,674) 99,290 (36,799)
Cash, cash equivalents and restricted cash at the beginning of the period 249,881 150,591 187,390
Cash, cash equivalents and restricted cash at the end of the period 234,207 249,881 150,591
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:      
Cash paid for interest 2,483 441  
NON-CASH INVESTING AND FINANCING INFORMATION:      
Change in net unrealizable gain (loss) on marketable securities $ 233 64 $ (24)
Warrant liability costs reclassified to additional paid-in equity on vested warrants issued 330    
Debt and equity issuance costs included in accounts payable and accrued expenses and other current liabilities   285  
Deferred offering costs reclassified to additional paid-in equity $ 364 $ 150