| Dec'19 | Dec'18 | Dec'17 | Dec'16 | Dec'15 | ||
|---|---|---|---|---|---|---|
Net loss | ||||||
-192,256 | -99,854 | -50,284 | -25,940 | -19,816 | ||
Adjustments to reconcile net loss to net cash flows used in operating activities: | ||||||
Stock-based compensation expense | ||||||
20,410 | 9,688 | 4,866 | 1,487 | 2,557 | ||
Depreciation expense | ||||||
800 | 300 | 200 | 90 | 73 | ||
Non-cash interest expense | ||||||
- | - | - | - | 2,091 | ||
Loss on disposal of property and equipment | ||||||
0 | 0 | -10 | -6 | - | ||
Net accretion of discounts on marketable securities | ||||||
3,999 | 0 | 0 | - | - | ||
Changes in operating assets and liabilities: | ||||||
Prepaid expenses and other current assets | ||||||
10,321 | 5,770 | 637 | 185 | 516 | ||
Operating lease assets | ||||||
-958 | - | - | - | - | ||
Accounts payable | ||||||
10,862 | 3,991 | 2,904 | -187 | 1,176 | ||
Accrued expenses and other current liabilities | ||||||
24,189 | 4,477 | 6,276 | 1,694 | - | ||
Operating lease liabilities | ||||||
-319 | - | - | - | - | ||
Accrued expenses | ||||||
- | - | - | - | 1,160 | ||
Other assets | ||||||
- | - | - | 55 | -6 | ||
Other long-term liabilities | ||||||
350 | 368 | 13 | - | - | ||
Net cash flows used in operating activities | ||||||
-149,296 | -86,783 | -36,702 | -23,090 | -13,269 | ||
Cash flows from investing activities: | ||||||
Purchases of marketable securities | ||||||
817,142 | 0 | 0 | - | - | ||
Maturities of marketable securities | ||||||
261,216 | 0 | 0 | - | - | ||
Sales of marketable securities | ||||||
100,780 | 0 | 0 | - | - | ||
Purchases of property and equipment | ||||||
4,935 | 1,125 | 406 | 223 | 142 | ||
Increase in restricted investments | ||||||
441 | 1,069 | 0 | - | - | ||
Net cash flows used in investing activities | ||||||
-460,522 | -2,194 | -406 | -223 | -142 | ||
Cash flows from financing activities: | ||||||
Proceeds from public offerings, net of underwriting discounts and commissions | ||||||
432,400 | 185,933 | 129,112 | - | - | ||
Proceeds from issuance of convertible preferred shares | ||||||
0 | 0 | 52,300 | 55,324 | 31,552 | ||
Proceeds from issuance of convertible notes payable to related parties | ||||||
- | - | - | - | 7,550 | ||
Repayment of notes payable to related party | ||||||
1,294 | 187 | 187 | 198 | 186 | ||
Payments of public offering costs | ||||||
620 | 674 | 4,395 | 104 | - | ||
Payments of convertible preferred share issuance costs | ||||||
0 | 0 | 429 | 25 | 498 | ||
Proceeds from exercise of stock options | ||||||
5,888 | 915 | 0 | - | - | ||
Net cash flows provided by financing activities | ||||||
436,374 | 185,987 | 176,401 | 54,997 | 38,418 | ||
Net increase (decrease) in cash and cash equivalents | ||||||
-173,444 | 97,010 | 139,293 | 31,684 | 25,007 | ||
Supplemental disclosure of cash flow information: | ||||||
Cash paid for interest | ||||||
67 | 84 | 95 | 106 | 117 | ||
Addition of operating lease asset included in accrued expenses and other current liabilities | ||||||
562 | 0 | 0 | - | - | ||
Supplemental disclosure of non-cash investing and financing activities: | ||||||
Amounts capitalized under build-to-suit lease transaction | ||||||
0 | 11,900 | 0 | - | - | ||
Conversion of notes payable and accrued interest into convertible preferred shares | ||||||
- | - | - | - | 97,793 | ||
Conversion of member units into Series A convertible preferred shares | ||||||
- | - | - | - | 8,491 | ||
Gain on extinguishment of notes payable to related party | ||||||
- | - | - | - | 1,487 | ||
Property and equipment purchases included in accounts payable and accrued expenses and other current liabilities | ||||||
661 | 0 | 78 | - | - | ||
Retirement of assets | ||||||
217 | 0 | 0 | - | - | ||
Conversion of convertible preferred shares into common stock | ||||||
0 | 0 | 244,538 | - | - | ||
Offering costs included in accounts payable and accrued expenses and other current liabilities | ||||||
553 | 0 | 0 | - | - | ||