Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|---|
| Deferred tax assets (liabilities): | |||
| Tax credit | $ 4,335,394 | $ 2,802,573 | |
| Net operating loss carryovers | 23,630,008 | 16,174,712 | |
| Property and equipment | 99,756 | (58,747) | |
| Research and development costs | 15,372,328 | 18,628,913 | |
| Start-up and organizational costs | 774 | 1,222 | |
| Stock-based compensation | 2,473,591 | 1,829,843 | |
| Other accruals | 260,113 | 341,090 | |
| Total gross deferred tax assets | 46,171,964 | 39,719,606 | |
| Less: valuation allowance | (46,171,964) | (39,719,606) | $ (22,085,888) |
| Deferred tax assets, net | $ 0 | $ 0 |
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- References No definition available.
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from in-process research and development costs expensed in connection with a business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from reserves and accruals, classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Deferred tax asset (liabilities), property plant and equipment. No definition available.
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