| In millions, except per share items | Sep-30-13 | Jun-30-13 | Mar-31-13 | Sep-30-12 | Jun-30-12 | Mar-31-12 | Dec-31-11 | Sep-30-11 |
| | 10-Q | 10-Q | 10-Q | 10-Q | 10-Q | 10-Q | 8-K | 10-Q |
| Cash flows from operating activities: | | | | | | | | |
| Net loss | -7.8 | -4.9 | -17.4 | -6.2 | -6.2 | -6.3 | | -7.4 |
| Adjustments to reconcile net loss to net cash used in operating activities: | | | | | | | | |
| Depreciation expense | | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | | 0.0 |
| Increase in fair value of warrants | | | 12.2 | | | | | |
| Stock-based compensation | | 0.6 | 1.3 | 0.7 | 0.4 | 0.3 | | 0.3 |
| Noncash interest expense | | 0.0 | 0.0 | 0.1 | 0.1 | 0.1 | | 0.1 |
| Changes in operating assets and liabilities: | | | | | | | | |
| Prepaid expenses and other current assets | | 0.1 | 0.0 | -0.3 | 0.1 | 0.1 | | 0.1 |
| Accounts payable | | 1.3 | -0.2 | 0.2 | 0.4 | -0.4 | | 1.1 |
| Accrued expenses | | -0.1 | 0.1 | 1.4 | 0.4 | 0.0 | | 0.2 |
| Net cash used in operating activities | | -2.9 | -3.9 | -4.1 | -4.8 | -6.2 | | -5.5 |
| |
| Cash flows from investing activities: | | | | | | | | |
| Payments under equipment funding agreement | | -0.4 | | | | | | -0.4 |
| Purchases of property and equipment | | -1.2 | -0.5 | 0.0 | -0.2 | -0.1 | | -0.1 |
| Net cash used in investing activities | | -1.7 | -0.5 | 0.0 | -0.2 | -0.1 | | -0.4 |
| |
| Cash flows from financing activities: | | | | | | | | |
| Proceeds from issuance of debt | | | | | | | | |
| Payment of debt issuance costs | | | | | | | | 0.0 |
| Repayment of debt | | -0.1 | -0.1 | -2.1 | -2.1 | -2.2 | | -0.6 |
| Proceeds from sale of common stock, net | | 2.7 | 0.0 | 0.0 | 0.0 | | | 0.4 |
| Proceeds from sale of convertible notes, net | | | | | | | | |
| Net cash (used in) provided by financing activities | | 2.6 | -0.1 | -2.1 | -2.1 | -2.2 | | -0.3 |
| |
| Net increase (decrease) in cash and cash equivalents | | -2.0 | -4.5 | -6.2 | -7.1 | -8.5 | | -6.2 |
| Cash and cash equivalents, beginning of period | | | 22.6 | | | 23.1 | | |
| Cash and cash equivalents, end of period | 10.3 | -2.0 | 18.0 | -6.2 | -7.1 | 14.6 | | -6.2 |
| |
| Supplemental cash flow disclosures: | | | | | | | | |
| Noncash investing and financing activities: | | | | | | | | |
| Conversion of note principal and accrued interest to common stock | | | | | | | | |
| Conversion of redeemable convertible preferred stock into common stock | | | | | | | | |
| Reclassification of warrant liability | | | 27.5 | | | | | |
| Fair value of warrants issued in connection with loan facility | | | | | | | | |
| Financing arrangement with third party vendors | | | | 0.4 | | | | 0.5 |
| Accretion of redeemable convertible preferred stock | | | | | | | | |
| Dividends | | | 0.3 | | | | | |
| Cash paid for interest | | 0.2 | 0.2 | 0.3 | 0.3 | 0.4 | | 0.4 |