| In millions, except per share items | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 | Dec-31-12 | Dec-31-11 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Operating expenses: | | | | | | | | |
| Research and development | 10.7 | 6.2 | 3.5 | 9.9 | 24.7 | 10.3 | 13.5 | 8.7 |
| General and administrative | 4.4 | 5.7 | 6.8 | 3.6 | 5.3 | 4.5 | 5.7 | 4.6 |
| Total operating expenses | 15.1 | 11.9 | 10.3 | 13.5 | 30.0 | 14.8 | 19.2 | 13.3 |
| |
| Other income (expense): | | | | | | | | |
| Interest expense | -0.7 | -0.2 | -0.4 | -0.7 | -0.7 | -1.3 | -2.0 | -0.9 |
| Interest income | 0.3 | 0.2 | 0.0 | 0.0 | 0.1 | | 0.1 | |
| Gain on revaluation of warrant liability | 8.7 | 3.3 | -0.3 | | 0.0 | 0.7 | | |
| Other income (expense), net | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | -0.2 | 0.1 | 0.0 |
| Total other income (expense) | 8.4 | 3.3 | -0.9 | -0.7 | -0.7 | -0.9 | -2.0 | -0.9 |
| Net loss | -6.8 | -8.6 | -11.2 | -14.2 | -30.7 | -11.1 | -21.2 | -14.2 |
| |
| Basic and diluted loss per share (in dollars per share) | ($0.23) | ($0.29) | ($0.49) | ($0.84) | ($1.85) | ($1.39) | ($6.94) | ($6.05) |
| |
| Weighted average number of outstanding shares – basic and diluted (in shares) | 30.1 | 30.1 | 23.0 | 16.9 | 16.6 | 8.0 | 3.1 | 2.3 |
| |
| Other comprehensive loss: | | | | | | | | |
| Total other comprehensive loss | -6.8 | -8.6 | -11.2 | -14.2 | -30.7 | -11.0 | -21.1 | -14.2 |