| In millions, except per share items | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 |
| | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| Net product sales | 21.1 | 18.2 | 12.3 | 2.3 | | | | |
| Operating costs and expenses: | | | | | | | | |
| Cost of sales | 1.2 | 1.2 | 0.9 | 0.3 | | | | |
| Research and development | 11.9 | 8.2 | 8.7 | 8.0 | 10.7 | 9.7 | 9.3 | 9.4 |
| Selling, general and administrative | 23.7 | 21.5 | 21.6 | 18.0 | 24.7 | 13.7 | 10.2 | 7.6 |
| Other operating expenses | -2.1 | -0.4 | | 11.0 | | | | |
| Total operating costs and expenses | 34.7 | 30.5 | 31.2 | 37.4 | 35.4 | 23.4 | 19.5 | 17.1 |
| Loss from operations | -13.6 | -12.2 | -18.9 | -35.1 | -35.4 | -23.4 | -19.5 | -17.1 |
| Operating margin | -64.5% | -67.0% | -153.2% | -1529.4% | | | | |
| |
| Non-operating expenses: | | | | | | | | |
| Interest expense, net | -3.8 | -3.6 | -3.8 | -2.1 | -1.4 | -0.7 | -0.2 | -0.2 |
| Other non-operating expenses | -0.1 | 0.1 | | | 0.0 | -0.1 | | |
| Total non-operating expenses | -3.9 | -3.5 | -3.8 | -2.1 | -1.4 | -0.8 | -0.2 | -0.2 |
| Net loss | -17.5 | -15.7 | -22.7 | -37.2 | -36.8 | -24.2 | -19.7 | -17.3 |
| |
| Net loss per common share: Basic (in dollars per share) | ($0.12) | ($0.13) | ($0.21) | ($0.37) | ($0.39) | ($0.26) | ($0.21) | ($0.23) |
| Net loss per common share: Diluted (in dollars per share) | ($0.12) | ($0.13) | ($0.21) | ($0.37) | ($0.39) | ($0.26) | ($0.21) | ($0.23) |
| |
| Shares used in calculation of net loss per common share, basic (in shares) | 114.7 | 121.6 | 108.5 | 99.8 | 90.1 | 93.8 | 92.3 | 76.4 |
| Shares used in calculation of net loss per common share, diluted (in shares) | 114.7 | 121.6 | 108.5 | 99.8 | 90.1 | 93.8 | 92.3 | 76.4 |