| In millions, except per share items | Jun-30-21 | Mar-31-21 | Dec-31-20 | Sep-30-20 | Jun-30-20 | Jun-05-20 | Mar-31-20 | Mar-05-20 |
| | 10-Q | 8-K | 10-K | 10-Q | 10-Q | 8-K | 10-Q | 8-K |
| Net sales | 8.8 | 8.1 | 7.1 | 9.4 | 2.0 | 2.0 | 1.7 | 1.7 |
| Net sales growth | 340.0% | 373.6% | 333.6% | | | | | |
| Grant and other income | 0.1 | 0.1 | 0.1 | 0.0 | 0.0 | 0.0 | 0.1 | 0.1 |
| Cost of goods sold | 3.4 | | 3.4 | 2.8 | 1.3 | | 1.8 | |
| Gross profit | 5.5 | 6.4 | 3.8 | 6.6 | 0.7 | 0.7 | 0.0 | 0.0 |
| Gross margin | 62.8% | 79.1% | 53.4% | 70.4% | 36.4% | 36.7% | -0.1% | -0.1% |
| |
| Operating expenses: | | | | | | | | |
| Research and development | 5.4 | 4.0 | 5.1 | 3.9 | 5.3 | 5.3 | 6.6 | 6.6 |
| Selling, general and administrative | 25.9 | 19.1 | 18.0 | 16.5 | 17.6 | 17.6 | 21.6 | 21.6 |
| Total operating expenses | 31.3 | 23.1 | 23.1 | 20.4 | 22.9 | 22.9 | 28.3 | 28.3 |
| Loss from operations | -25.8 | -16.7 | -19.3 | -13.7 | -22.2 | -22.2 | -28.3 | -28.3 |
| Operating margin | -293.0% | -207.9% | -274.2% | -146.2% | -1110.3% | -1118.1% | -1662.0% | -1685.8% |
| |
| Other income (expense): | | | | | | | | |
| Interest and other income | 0.1 | | 2.0 | 0.2 | 0.3 | | 0.4 | |
| Interest expense | -1.8 | -1.8 | -4.6 | -2.3 | -2.2 | | -1.5 | |
| Change in fair value of warrants | 0.0 | | 0.1 | -0.2 | 0.0 | | 0.1 | |
| Total other income (expense) | -1.7 | 1.7 | -2.5 | -2.3 | -2.0 | -2.0 | -0.9 | -0.9 |
| Net loss before benefit from income taxes | -27.5 | | -21.9 | -16.0 | -24.2 | | -29.2 | |
| Benefit from income taxes | | | 0.2 | | -0.1 | -0.1 | | |
| Net loss | -27.5 | -18.4 | -21.9 | -16.0 | -24.1 | -24.1 | -29.2 | -29.2 |
| |
| Other comprehensive income (loss), net of tax: | | | | | | | | |
| Unrealized gains (losses) on investments | 0.0 | | 0.0 | -0.1 | 0.1 | | | |
| Foreign currency translation adjustments | 0.0 | | 0.0 | 0.0 | 0.0 | | 0.0 | |
| Comprehensive loss | -27.5 | | | | -24.0 | | | |
| |
| Net loss per common share - basic and diluted | ($0.41) | ($0.30) | ($0.36) | ($0.35) | ($0.63) | ($0.63) | ($0.89) | ($0.89) |
| |
| Weighted average common shares outstanding - basic and diluted | 66.4 | 61.2 | 42.6 | 46.1 | 38.0 | 38.0 | 32.8 | 32.8 |