| Dec'19 | Dec'18 | Dec'17 | Dec'16 | Dec'15 | Dec'14 | Dec'13 | Dec'12 | Dec'11 |
|---|---|---|---|---|---|---|---|---|
Statement of Cash Flows [Abstract] | ||||||||
Cash flows from operating activities: | ||||||||
Net loss | ||||||||
-789,608 | -555,625 | -335,643 | -263,507 | -166,783 | -48,709 | -25,321 | -23,670 | -15,598 |
Adjustments to reconcile net loss to net cash used in operating activities: | ||||||||
Change in fair value of contingent consideration | ||||||||
2,747 | 2,999 | -2,189 | 2,675 | 2,344 | 246 | - | - | - |
Depreciation and amortization | ||||||||
17,434 | 17,158 | 13,538 | 9,648 | 7,419 | 4,228 | 941 | 301 | 225 |
Stock-based compensation expense | ||||||||
160,629 | 110,836 | 53,282 | 39,756 | 41,120 | 10,763 | 6,491 | 822 | 863 |
Unrealized loss on equity securities | ||||||||
-9,297 | 2,154 | 0 | - | - | - | - | - | - |
Other non-cash items | ||||||||
11,000 | 5,880 | -3,153 | -2,825 | 1,513 | 142 | 9 | - | - |
Issuance of restricted common stock in exchange for consulting services to non-employees | ||||||||
- | - | - | - | - | 168 | - | - | - |
Noncash benefit on release of tax valuation allowance | ||||||||
- | - | - | - | - | 11,797 | - | - | - |
Re-measurement of warrants | ||||||||
- | - | - | - | - | - | 440 | -28 | 361 |
Loss on disposal of equipment | ||||||||
- | - | - | - | - | - | - | -10 | - |
Changes in operating assets and liabilities: | ||||||||
Prepaid expenses and other assets | ||||||||
13,913 | 24,288 | 20,092 | 14,318 | 6,847 | -307 | 4,214 | -93 | 337 |
Operating lease right-of-use assets | ||||||||
22,496 | - | - | - | - | - | - | - | - |
Accounts payable | ||||||||
23,600 | 3,614 | 526 | 6,658 | 2,541 | -2,249 | 2,067 | 380 | 870 |
Accrued expenses and other liabilities | ||||||||
46,291 | 37,832 | 5,848 | 22,051 | 9,423 | 9,969 | 761 | 1,336 | 363 |
Operating lease liabilities | ||||||||
-9,944 | - | - | - | - | - | - | - | - |
Deferred revenue | ||||||||
-16,674 | -41,872 | 1,024 | 4,565 | 11,171 | -24,871 | 54,868 | -340 | 1,019 |
Collaboration research advancement | ||||||||
5,739 | -43,954 | 0 | - | - | - | - | - | - |
Deferred rent | ||||||||
- | - | - | - | -330 | 2,110 | 7,408 | 52 | 17 |
Net cash used in operating activities | ||||||||
-564,400 | -413,426 | -280,553 | -189,647 | -98,429 | -59,693 | 43,450 | -21,044 | -12,217 |
Cash flows from investing activities: | ||||||||
Restricted cash | ||||||||
- | - | - | - | 8,816 | -209 | 1,153 | 40 | 35 |
Purchase of property, plant and equipment, including assets under financing lease obligation | ||||||||
71,028 | 55,737 | 62,242 | 28,029 | 7,055 | 8,708 | 8,670 | 867 | 403 |
Purchases of marketable securities | ||||||||
756,570 | 1,517,982 | 686,204 | 348,225 | 755,175 | 174,981 | - | - | 5,276 |
Proceeds from maturities of marketable securities | ||||||||
1,340,629 | 894,284 | 431,816 | 443,364 | 199,179 | 30,960 | - | 3,506 | 1,750 |
Purchase of intangible assets | ||||||||
5,224 | 0 | 0 | - | - | - | - | - | - |
Repayment of nonrecourse note collateralized by restricted stock | ||||||||
- | - | - | - | - | - | 344 | - | - |
Net cash provided by (used in) investing activities | ||||||||
507,807 | -679,435 | -316,630 | 67,110 | -571,867 | -157,193 | -9,823 | 2,599 | -3,964 |
Cash flows from financing activities: | ||||||||
Proceeds from public offering of common stock, net of issuance costs | ||||||||
- | - | - | - | 477,064 | 353,226 | 104,921 | 59,831 | 32,404 |
Acquisition of business, net of cash acquired | ||||||||
- | - | - | - | - | 4,673 | - | - | - |
Cash paid for contingent purchase price consideration | ||||||||
0 | 0 | 1,074 | 2,025 | 453 | - | - | - | - |
Reimbursement of assets under financing lease obligation | ||||||||
0 | 3,098 | 38,021 | 1,663 | - | - | - | - | - |
Payments on financing lease obligation | ||||||||
- | 1,017 | 574 | - | - | - | - | - | - |
Proceeds from issuance of common stock | ||||||||
0 | 649,368 | 1,006,570 | 234,962 | 10,109 | 5,226 | 376 | - | - |
Proceeds from exercise of stock options and issuance of common stock | ||||||||
- | - | - | - | - | - | - | 21 | - |
Proceeds from sale of restricted stock, net of issuance costs | ||||||||
- | - | - | - | - | - | - | - | 30 |
Proceeds from exercise of stock options and ESPP contributions | ||||||||
21,187 | 31,759 | 33,231 | 6,934 | - | - | - | - | 1 |
Net cash provided by financing activities | ||||||||
21,187 | 737,692 | 1,076,174 | 241,534 | 486,720 | 358,452 | 105,641 | 59,852 | 32,435 |
Increase (decrease) in cash, cash equivalents and restricted cash | ||||||||
-35,390 | -355,169 | 478,991 | 118,997 | -183,576 | 141,566 | 139,268 | 41,407 | 16,254 |
Supplemental cash flow disclosures from investing and financing activities: | ||||||||
Assets acquired under financing lease obligation | ||||||||
0 | 0 | 3,271 | 48,034 | 61,901 | - | - | - | - |
Purchases of property, plant and equipment included in accounts payable and accrued expenses | ||||||||
5,286 | 7,449 | 2,566 | 6,363 | 2,089 | 387 | 1,924 | - | - |
Right-of-use assets obtained in exchange for operating lease liabilities | ||||||||
23,939 | - | - | - | - | - | - | - | - |
Supplemental cash flow disclosures: | ||||||||
Cash paid during the period for interest | ||||||||
0 | 15,494 | 11,411 | - | - | - | - | - | - |
Cash paid during the period for income taxes | ||||||||
637 | 358 | 91 | - | - | - | - | - | - |
Accretion and dividends on convertible preferred stock | ||||||||
- | - | - | - | - | - | - | 3,057 | 4,993 |
Gain on extinguishment of convertible preferred stock | ||||||||
- | - | - | - | - | - | - | -23,114 | - |
Reclassification of warrants to additional paid-in capital | ||||||||
- | - | - | - | - | - | 655 | 394 | - |
Reclassification of Series A-1 Preferred Stock to common stock | ||||||||
- | - | - | - | - | - | - | 2,337 | - |
Conversion of preferred stock to common stock upon closing of IPO | ||||||||
- | - | - | - | - | - | 122,178 | - | - |
Stock option exercise proceeds receivable | ||||||||
- | - | - | - | - | - | 107 | - | - |
Offering expenses included in accounts payable and accrued expenses | ||||||||
- | - | - | - | - | 183 | - | - | - |
Tenant improvements under financing lease included in tenant improvements receivable | ||||||||
- | - | - | 8,542 | - | - | - | - | - |
Regeneron Collaboration Agreement | ||||||||
Proceeds from issuance of common stock | ||||||||
0 | 54,484 | 0 | - | - | - | - | - | - |