| In millions, except per share items | Sep-30-17 | Jun-30-17 | Mar-31-17 | Dec-31-16 | Sep-30-16 | Jun-30-16 | Mar-31-16 | Dec-31-15 |
| | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q |
| Net revenue: | | | | | | | | |
| Product sales, net | 3.2 | 3.1 | 2.8 | 2.2 | 2.2 | 2.5 | 2.6 | 2.7 |
| License and development revenue | 0.4 | 0.3 | 0.3 | 1.6 | 1.5 | 1.5 | 1.4 | |
| Royalty revenue | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Total net revenue | 3.7 | 3.4 | 3.1 | 3.9 | 3.8 | 4.1 | 4.0 | 2.7 |
| Total net revenue growth | -3.1% | -15.6% | -23.6% | 42.1% | 40.7% | 35.6% | 22.0% | -26.2% |
| Operating costs and expenses: | | | | | | | | |
| Cost of product sales | 4.2 | 3.8 | 3.8 | 3.4 | 3.4 | 3.9 | 3.7 | 3.6 |
| Research and development | 6.5 | 6.6 | 6.7 | 6.2 | 6.5 | 6.3 | 6.6 | 7.0 |
| Selling, general and administrative | 7.5 | 7.7 | 8.4 | 8.5 | 8.8 | 9.4 | 8.9 | 9.2 |
| Total operating costs and expenses | 18.2 | 18.0 | 18.9 | 18.2 | 18.6 | 19.6 | 19.2 | 19.7 |
| Loss from operations | -14.6 | -14.6 | -15.8 | -14.4 | -14.9 | -15.6 | -15.2 | -17.0 |
| Operating margin | -399.6% | -426.3% | -511.6% | -371.8% | -394.2% | -383.6% | -376.0% | -625.2% |
| Interest income | 0.0 | 0.0 | 0.0 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Interest expense | -0.6 | -0.5 | -0.5 | -0.5 | -0.5 | -0.5 | -0.5 | -0.5 |
| Other income (expense), net | -1.7 | -2.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Net loss | -16.8 | -17.2 | -16.3 | -14.9 | -15.3 | -16.0 | -15.6 | -17.4 |
| Deemed dividend attributable to convertible preferred stock | -8.8 | -8.7 | | | | | | |
| Net loss allocable to common stockholders | -29.6 | -29.9 | | | -19.9 | -16.0 | | |
| |
| Basic net loss per share allocable to common stockholders (in dollars per share) | ($1.98) | ($2.33) | ($1.82) | ($1.66) | ($1.71) | ($1.79) | ($1.76) | ($1.96) |
| Diluted net loss per share allocable to common stockholders | ($1.98) | ($2.33) | ($1.82) | ($1.66) | ($1.71) | ($1.79) | ($1.76) | ($1.96) |
| |
| Shares used in computing basic net loss per share allocable to common stockholders | 17.9 | 9.5 | 8.9 | 8.9 | 8.9 | 8.9 | 8.9 | 8.9 |
| Shares used in computing diluted net loss per share allocable to common stockholders | 18.5 | 9.5 | 8.9 | 8.9 | 8.9 | 8.9 | 8.9 | 8.9 |