Certain Balance Sheet Items |
Certain Balance Sheet Items Accounts receivable, net consisted of the following: | | | | | | | | | | | | December 31, 2013 | | December 31, 2012 | Accounts receivable from product sales to collaborators | | $ | 4,495,314 |
| | $ | — |
| Accounts receivable from revenues under collaborative agreements | | 3,707,248 |
| | 15,058,163 |
| Accounts receivable from other product sales | | 1,505,004 |
| | 823,064 |
| | | 9,707,566 |
| | 15,881,227 |
| Allowance for distribution fees and discounts | | (610,482 | ) | | (178,140 | ) | | | $ | 9,097,084 |
| | $ | 15,703,087 |
|
Inventories consisted of the following: | | | | | | | | | | | | December 31, 2013 | | December 31, 2012 | Raw materials | | $ | 1,136,815 |
| | $ | 1,127,061 |
| Work-in-process | | 4,280,076 |
| | 792,257 |
| Finished goods | | 753,091 |
| | 751,378 |
| | | $ | 6,169,982 |
| | $ | 2,670,696 |
|
Prepaid expenses and other assets consisted of the following: | | | | | | | | | | | | December 31, 2013 | | December 31, 2012 | Prepaid manufacturing expenses | | $ | 5,884,040 |
| | $ | 8,152,602 |
| Prepaid research and development expenses | | 3,522,250 |
| | 2,274,551 |
| Other prepaid expenses | | 1,338,758 |
| | 2,250,791 |
| Other assets | | 356,328 |
| | 74,944 |
| | | 11,101,376 |
| | 12,752,888 |
| Less long-term portion | | 2,675,692 |
| | — |
| | | $ | 8,425,684 |
| | $ | 12,752,888 |
|
Property and equipment, net consisted of the following: | | | | | | | | | | | | December 31, 2013 | | December 31, 2012 | Research equipment | | $ | 7,713,850 |
| | $ | 6,360,004 |
| Computer and office equipment | | 1,948,859 |
| | 1,432,975 |
| Leasehold improvements | | 1,408,025 |
| | 1,138,110 |
| Building(1) | | — |
| | 1,450,000 |
| | | 11,070,734 |
| | 10,381,089 |
| Accumulated depreciation and amortization | | (7,649,228 | ) | | (6,680,627 | ) | | | $ | 3,421,506 |
| | $ | 3,700,462 |
|
________________________ | | (1) | Represented capitalized building under a build-to-suit lease arrangement where we were considered the owner (for accounting purposes only) during the construction period. Upon the completion of the building construction in the fourth quarter of 2013, we met the sale-leaseback criteria for de-recognition of the building asset and liability; therefore, the building asset was removed from the consolidated balance sheet as of December 31, 2013. |
Depreciation and amortization expense was approximately $1.2 million, $1.1 million and $1.1 million for the years ended December 31, 2013, 2012 and 2011, respectively. Accrued expenses consisted of the following: | | | | | | | | | | | | December 31, 2013 | | December 31, 2012 | Accrued compensation and payroll taxes | | $ | 7,075,347 |
| | $ | 4,053,590 |
| Accrued outsourced research and development expenses | | 3,377,256 |
| | 1,239,050 |
| Accrued outsourced manufacturing expenses | | 3,233,012 |
| | 984,192 |
| Other accrued expenses | | 1,234,831 |
| | 1,506,615 |
| | | $ | 14,920,446 |
| | $ | 7,783,447 |
|
Deferred revenue consisted of the following: | | | | | | | | | | | | December 31, 2013 | | December 31, 2012 | Collaborative agreements | | $ | 51,184,897 |
| | $ | 43,222,473 |
| Product sales | | 1,958,381 |
| | 623,510 |
| Total deferred revenue | | 53,143,278 |
| | 43,845,983 |
| Less current portion | | 7,397,829 |
| | 8,891,017 |
| Deferred revenue, net of current portion | | $ | 45,745,449 |
| | $ | 34,954,966 |
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