Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] |
| | 2016 | | 2015 | | | | | | | | Tax provision (benefit) | | | | | | | | Current | | | | | | | | Federal | | $ | | | $ | | | State | | | | | | | | Total current | | | | | | | | | | | | | | | | Deferred | | | | | | | | Federal | | | (4,053,114) | | | (3,105,641) | | State | | | 99,883 | | | 42,562 | | Total deferred | | | (3,953,231) | | | (3,063,079) | | | | | | | | | | Change in valuation allowance | | | 3,953,231 | | | 3,063,079 | | Total | | $ | | | $ | | |
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Schedule of Deferred Tax Assets and Liabilities [Table Text Block] |
Deferred tax assets consisted of the following at December 31:
| | 2016 | | 2015 | | | | | | | | Deferred tax assets | | | | | | | | Federal net operating loss | | $ | 36,472,996 | | $ | 32,565,906 | | Federal research and development tax credit carryforwards | | | 3,808,862 | | | 2,858,628 | | State net operating losses and tax credit carryforwards | | | 2,628,006 | | | 2,619,290 | | Capitalized research and development expenses | | | 8,834,640 | | | 9,883,932 | | Stock-based compensation expense | | | 2,162,703 | | | 1,993,664 | | Other | | | 235,681 | | | 289,643 | | Total deferred tax assets | | | 54,142,888 | | | 50,211,063 | | | | | | | | | | Deferred tax liabilities | | | | | | | | Depreciable assets | | | (150,196) | | | (171,602) | | Total deferred tax liabilities | | | (150,196) | | | (171,602) | | | | | | | | | | Net deferred tax assets | | | 53,992,692 | | | 50,039,461 | | Less valuation allowance | | | (53,992,692) | | | (50,039,461) | | Total deferred tax assets | | $ | | | $ | | |
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