| In millions, except per share items | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-05-18 | Dec-31-17 |
| | 10-K | 10-K | 10-K | 10-K | 8-K | S-1/A |
| Cash flows from operating activities | | | | | | |
| Net loss | -100.7 | -70.5 | -45.7 | -16.5 | | |
| |
| Adjustments to reconcile net loss to net cash used in operating activities: | | | | | | |
| Stock-based compensation expense | 11.9 | 7.0 | 3.3 | 0.2 | | |
| Depreciation | 0.1 | 0.1 | 0.0 | | | |
| Amortization and accretion of long-term debt related costs | 1.4 | | | | | |
| Reduction in the carrying amount of the right-of-use assets | 0.5 | 0.4 | 0.2 | | | |
| Changes in assets and liabilities: | | | | | | |
| Accounts receivable, net | -6.7 | | | | | |
| Inventory | -7.0 | | | | | |
| Prepaid expenses and other current assets | -5.7 | -0.4 | -2.6 | 0.5 | | |
| Other assets | -0.1 | | | 0.0 | | |
| Accounts payable | 3.9 | 1.8 | 0.0 | 0.0 | | |
| Accrued expenses and other current liabilities | 13.1 | 3.7 | -4.2 | -1.2 | | |
| Net cash used in operating activities | -89.4 | -58.4 | -40.8 | -17.1 | | |
| |
| Cash flows from investing activities | | | | | | |
| Purchases of property and equipment | -1.5 | -0.7 | -0.2 | | | |
| Net cash used in investing activities | -1.5 | -0.7 | -0.2 | | | |
| |
| Cash flows from financing activities | | | | | | |
| Payment of deferred offering costs | 0.0 | -0.4 | | | | |
| Proceeds from the exercise of stock options | 1.6 | 0.3 | 0.0 | | | |
| Net cash provided by financing activities | 91.6 | 112.5 | 175.0 | | | |
| |
| Reconciliation of cash, cash equivalents and restricted cash | | | | | | |
| Cash and cash equivalents | | | | | | |
| |
| Cash paid during the period for: | | | | | | |
| Interest | 2.4 | | | | | |
| Non-cash investing and financing activities: | | | | | | |
| Right-of-use assets acquired through leases | 2.8 | 0.3 | | | | |