| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Cash flows from operating activities: | | | | | | | | |
| Net loss | -9.5 | -9.7 | -3.1 | -7.6 | -5.9 | -5.2 | -5.9 | -2.8 |
| Adjustments to reconcile net loss to net cash used in operating activities: | | | | | | | | |
| Stock-based compensation expense | 1.6 | 1.5 | 1.5 | 2.4 | 1.9 | 3.4 | 3.9 | 0.8 |
| Changes in operating assets and liabilities: | | | | | | | | |
| Prepaid expenses and other current assets | 1.7 | -1.1 | -7.1 | 0.1 | -2.6 | -1.1 | -0.1 | 0.1 |
| Accounts payable | -3.0 | 0.2 | 2.1 | 0.9 | 0.0 | 0.2 | 0.4 | 0.2 |
| Accrued expenses | -0.4 | -2.5 | 3.1 | 0.3 | -0.1 | -0.4 | 0.0 | 0.1 |
| Net cash used in operating activities | -9.6 | -11.6 | -3.6 | -4.0 | -6.7 | -3.0 | -1.8 | -1.7 |
| |
| Cash flows from financing activities: | | | | | | | | |
| Proceeds from issuance of common stock, net of issuance costs | 8.6 | | | | | | | |
| Proceeds from exercise of stock options | 0.0 | 0.0 | | | | 0.0 | | |
| Net cash provided by financing activities | 8.6 | 0.0 | | | | 0.0 | | 0.0 |
| Net (decrease) increase in cash and cash equivalents | -1.0 | -11.6 | -3.6 | -4.0 | -6.7 | -3.0 | -1.8 | -1.8 |