| Cash and cash equivalents | |
| Short-term investments | |
| Receivable from collaboration partners (Note 2) | |
| Prepaid expenses and other current assets | |
| Total current assets | |
| Property and equipment, net | |
| Restricted cash | |
| Other non-current assets | |
| Total assets | |
| Accounts payable | |
| Accrued expenses | |
| Deferred revenue | |
| Other current liabilities | |
| Total current liabilities | |
| Deferred revenue, net of current | |
| Other non-current liabilities | |
| Total liabilities | |
| Contingencies (Note 11) | |
| Preferred stock, $0.01 par value per share; 1,000,000 shares authorized; no shares issued and outstanding | |
| Common stock, $0.01 par value per share; 50,000,000 shares authorized; issued and outstanding shares 34,906,744 at June 30, 2011 and 34,573,829 at December 31, 2010 | |
| Additional paid-in capital | |
| Accumulated other comprehensive gain | |
| Accumulated deficit | |
| Total stockholders' equity | |
| Total liabilities and stockholders' equity |