CONSOLIDATED BALANCE SHEETS - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Current assets:    
Cash and cash equivalents $ 76,938 $ 88,915
Prepaid manufacturing services 7,315 101
Prepaid expenses and other current assets 5,918 4,742
Total current assets 90,171 93,758
Property and equipment, net 23,479 31,410
Restricted cash 4,170 4,170
Operating right-of-use assets 21,957 22,003
Prepaid manufacturing services, net of current portion 31,893  
Total assets 171,670 151,341
Current liabilities:    
Accounts payable 1,838 2,018
Accrued expenses 9,703 8,870
Deferred revenue 12,963 5,281
Operating lease liabilities 2,661 1,482
Total current liabilities 27,165 17,651
Long-term liabilities:    
Deferred revenue, net of current portion 30,686 57,416
Note payable, net of discount 25,430 24,960
Operating lease liabilities, net of current portion 34,884 36,540
Other long-term liabilities   207
Total liabilities 118,165 136,774
Commitments and contingencies (Note 8)
Stockholders' equity:    
Common stock, $0.0001 par value; 150,000,000 shares authorized as of December 31, 2021 and December 31, 2020; 22,383,830 and 18,787,579 shares issued and outstanding as of December 31, 2021 and December 31, 2020, respectively 2 2
Additional paid-in capital 378,750 302,655
Accumulated deficit (325,247) (288,090)
Total stockholders' equity 53,505 14,567
Total liabilities and stockholders' equity $ 171,670 $ 151,341