| Schedule of Deferred Tax Assets and Liabilities [Table Text Block] |
As of December 31, 2016, and 2015, the Company’s deferred tax assets (liabilities) consisted of the effects of temporary differences attributable to the following: | | | December 31, | | | | | 2016 | | 2015 | | | Deferred tax assets (liabilities): | | | | | | | | | Tax credit | | $ | 2,802,573 | | $ | 2,958,771 | | | Net operating loss carryovers | | | 16,174,712 | | | 7,511,765 | | | Property and equipment | | | (58,747) | | | (98,235) | | | Research and development costs | | | 18,628,913 | | | 10,380,961 | | | Start-up and organizational costs | | | 1,222 | | | 1,333 | | | Stock-based compensation | | | 1,829,843 | | | 1,175,821 | | | Other accruals | | | 341,090 | | | 155,472 | | | Total gross deferred tax assets | | | 39,719,606 | | | 22,085,888 | | | Less: valuation allowance | | | (39,719,606) | | | (22,085,888) | | | Deferred tax assets, net | | $ | - | | $ | - | |
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| Summary of Valuation Allowance [Table Text Block] |
The change in the Company’s valuation allowance is as follows:
| | | 2016 | | 2015 | | | January 1, | | $ | 22,085,888 | | $ | 9,630,687 | | | Increase in valuation allowance | | | 17,633,718 | | | 12,455,201 | | | December 31, | | $ | 39,719,606 | | $ | 22,085,888 | |
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| Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] |
| | | For the Year Ended December 31, | | | | | 2016 | | | 2015 | | | Tax benefit at federal statutory rate | | | (34.0) | % | | | (34.0) | % | | State income taxes | | | (5.7) | | | | (5.5) | | | Permanent differences: | | | | | | | | | | Stock-based compensation | | | 0.8 | | | | 1.3 | | | Meals and entertainment | | | 0.1 | | | | 0.1 | | | True-up of federal deferred taxes | | | 1.7 | | | | | | | True-up of state deferred taxes | | | 1.2 | | | | (0.2) | | | Other | | | - | | | | 0.7 | | | Research and development tax credit, federal | | | (1.5) | | | | (4.4) | | | Research and development tax credit, state | | | (1.1) | | | | (3.1) | | | Increase in valuation allowance, federal | | | 32.9 | | | | 36.3 | | | Increase in valuation allowance, state | | | 5.6 | | | | 8.8 | | | Effective income tax rate | | | 0.0 | % | | | 0.0 | % |
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