Annual report pursuant to Section 13 and 15(d)

Consolidated Statements of Cash Flows

v3.20.4
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Operating activities      
Net loss $ (306,620) $ (290,976) $ (230,699)
Adjustments to reconcile net loss to net cash used in operating activities:      
Stock-based compensation expense 51,351 51,696 33,817
Depreciation and amortization expense 8,332 7,070 3,732
Non-cash operating lease expense 1,457 964 0
Amortization (accretion) of investment premiums (discounts) 828 (1,330) (1,885)
Loss on disposals of property and equipment 130 1,027 0
Asset retirement obligation accretion expense 78 71 49
Non-cash interest expense 0 0 211
Changes in operating assets and liabilities:      
Accounts receivable (1,250) 0 0
Prepaid expenses and other current assets (8,666) (998) (5,764)
Operating lease assets 886 239 0
Other assets (219) 322 (314)
Accounts payable (815) 4,213 (1,958)
Accrued compensation 5,752 4,070 4,972
Accrued research and development expenses 7,472 (10,869) 15,204
Other current liabilities (187) (394) 2,491
Deferred revenue 61,250 0 0
Operating lease liabilities (1,316) (731) 0
Other long-term liabilities 778 0 372
Net cash used in operating activities (180,759) (235,626) (179,772)
Investing activities      
Purchases of short-term investments (425,868) (270,230) (466,489)
Proceeds from maturities and sales of short-term investments 309,653 336,261 306,125
Purchases of property and equipment (4,513) (5,733) (35,925)
Proceeds from sale of property and equipment 0 161 0
Net cash (used in) provided by investing activities (120,728) 60,459 (196,289)
Financing activities      
Proceeds from sale of common stock and pre-funded warrants in underwritten offerings, net 353,780 140,888 293,290
Proceeds from issuance of common stock through ATM facilities, net 69,189 47,729 47,586
Proceeds from employee stock awards 6,680 7,350 24,691
Taxes paid related to net share settlement of restricted stock units (1,521) (6,695) (7,503)
Principal payments on finance and capital lease obligations (389) (486) (528)
Other financing activities, net (165) 0 0
Net cash provided by financing activities 427,574 188,786 357,536
Increase (decrease) in cash, cash equivalents and restricted cash 126,087 13,619 (18,525)
Cash, cash equivalents and restricted cash at beginning of period 75,711 62,092 80,617
Cash, cash equivalents and restricted cash at end of period 201,798 75,711 62,092
Non-cash investing and financing activities      
Property and equipment purchases included in accounts payable and other accrued liabilities 326 276 1,579
Accrued costs related to underwritten public offering 192 172 0
Proceeds from issuance of common stock through ATM facilities not yet received 0 1,185 0
Capitalized lease obligations 0 0 441
Property and equipment acquired under capital leases 0 0 191
Asset retirement costs 0 0 88
Interest capitalized during construction period for build-to-suit lease arrangement 0 0 77
Supplemental cash flow disclosure      
Cash paid for interest 62 50 240
Cash paid for income taxes $ 10 $ 0 $ 0