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Goodwill and Intangible Assets Disclosure [Abstract]

Exchange Agreements

5. Exchange Agreements

On June 29, 2018 we closed on privately negotiated exchange agreements with certain investors to exchange warrants to purchase 1,593,753 common shares of the Company in exchange for:

(i)

5,030,991 shares of the Company’s common stock valued at approximately $0.42 per share;

(ii)

Convertible notes with an initial aggregate principal balance of $1,500,000, and;

(iii)

$1,100,000 in cash consideration (the “First Exchange”).

The total fair value of the consideration given in exchange for the warrants in the First Exchange was $4,727,000; which exceeded the March 31, 2018 fair value of the warrants by $3,467,935. The warrant fair value at March 31, 2018 was determined assuming an orderly transaction between market participants, using a Monte Carlo simulation valuation model. The Company was compelled to enter into the exchange transaction as Management believes the dilutive features of the common stock warrants prevented the Company from obtaining sufficient financing on acceptable terms. Accordingly, the Company recorded a loss on exchange of warrants of $3,593,082, inclusive of transaction costs of $125,147, which is reported in changes in fair value of warrant liability including loss on exchange. The Company additionally agreed to redeem the First Exchange investors’ remaining shares of Series B Preferred Stock at their face value of $2,364,044. Since the redemption occurred prior to the stated maturity date, $56,792 of the redemption price is considered a deemed dividend.

Subsequent to the First Exchange, the Company negotiated exchange agreements to issue 4,351,136 shares of common stock in exchange for warrants to purchase 675,679 common shares of the Company (the “Second Exchange”). The Second Exchange agreements were signed in July 2018. A portion of the consideration to be issued pursuant to the Second Exchange is subject to shareholder approval which the Company is seeking at its annual shareholder meeting scheduled for August 30, 2018. The consideration offered in this Second Exchange is considered to be substantially similar to the fair value on a per warrant basis of the First Exchange. Accordingly, the Company considers this transaction to be reflective of the fair value of the warrant liability at June 30, 2018 and the remaining 756,332 unexchanged warrants at June 30, 2018 are valued at $2,229,431, or $2.97 per warrant. The Company additionally agreed to convert the Second Exchange investors’ remaining shares of Series B Preferred Stock for 963,711 shares of common stock and $22,241.

The following is a summary of the income statement effect of changes in the Company’s outstanding warrants:


	Three Months Ended June 30, 2018		Six Months Ended June 30, 2018
Changes in fair value of warrants		1,635,609		87,627
Loss on warrants exchange June 29, 2018		3,467,935		3,467,935
Transaction Costs		125,147		125,147

Change in fair value of warrant liability, including loss on exchange	$	5,228,691	$	3,680,709

In conjunction with the First Exchange the Company issued convertible notes (the “Exchange Notes”) with an aggregate principal value of $1,500,000, which are initially convertible into up to 2,205,883 shares of our common stock at the holder’s option on the maturity date. The notes are also convertible in the event of default, at which time the balance of the note increases by 112% and is convertible at a share price equal to the lower of $0.68 per share or 75% of the weighted average price of common stock during the twenty consecutive trading day period immediately preceding the event of default. In the event the weighted average price of common stock as defined above is below $0.15 per share, then a supplemental cash payment is due to the note holder.

The Exchange Notes mature on December 29, 2018, when the entire principal and any unpaid interest will be due. These notes earn interest at a stated rate of 1% each month and interest is payable on the last business day of each month.

The conversion and redemption options embedded in the Exchange Notes qualify for derivative accounting under ASC 815-15 “Derivatives and Hedging”. The fair value of the derivative liability resulted in a discount to the convertible note of $180,611, making the carrying value of the note $1,319,389. The carrying value of the convertible note will be accreted over the term of the convertible note, beginning in Q3 2018. Additionally, $58,172 in debt issuance costs were capitalized and will be recognized over the term of the note.

The value of the shares of the Company’s common stock which were part of the exchange consideration were valued at a 5% discount to the June 29, 2018 closing price. This amount is considered a marketability discount calculated based on an analysis of the leak out provision provided for in the exchange agreements. The key assumptions used in calculating the marketability discount were:


Holding period, in years	0.03
Risk free rate	1.77	%
Dividend yield	0	%
Volatility	109.9	%

Net Loss Per Share

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Net Loss Per Share

6. Net Loss Per Share

Because we have reported a net loss attributable to common stockholders for all periods presented, basic and diluted net loss per share attributable to common stockholders are the same for all periods presented. For periods presented, all preferred stock, unvested restricted stock, common stock warrants, and stock options have been excluded from the computation of diluted weighted-average shares outstanding because such securities would have an antidilutive impact.

The following table sets forth the computation of basic and diluted net loss per share:


	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Numerator:
Net loss	$	(9,138,842	)	$	(3,110,382	)	$	(12,312,380	)	$	(7,689,164	)
Less: Preferred stock accretion and dividends		(700,093	)		(44,713	)		(2,591,414	)		(163,069	)

Net loss attributed to common stockholders	$	(9,838,935	)	$	(3,155,095	)	$	(14,903,794	)	$	(7,852,233	)

Denominator:
Weighted-average common shares outstanding, basic and diluted		28,530,423			12,245,701			24,361,010			9,596,423

Net loss per share attributed to common stockholders, basic and diluted	$	(0.34	)	$	(0.26	)	$	(0.61	)	$	(0.82	)

Potential common shares issuable upon conversion, vesting or exercise of preferred stock, unvested restricted stock, common stock warrants, and stock options that are excluded from the computation of diluted weighted-average shares outstanding are as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Preferred stock		208,989		—		208,989		—
Common stock warrants		756,332		4,658		756,332		4,658
Common stock options		1,615,380		1,469,659		1,615,380		1,469,659
Restricted stock		19,168		36,962		19,168		36,962

Intangible Assets

6 Months Ended

Jun. 30, 2018

Intangible Assets

7. Intangible Assets

Our intangible assets consisted of the following:


	June 30, 2018
	Estimated Useful Lives		Gross Carrying Value		Accumulated Amortization			Net Book Value
Internally developed patents		6-10 years	$	711,616	$	(270,869	)	$	440,747
Acquired licenses		16-20 years		285,000		(245,526	)		39,474

Total intangible assets subject to amortization				996,616		(516,395	)		480,221
IPR&D assets		Indefinite		37,868,968		—			37,868,968

Total			$	38,865,584	$	(516,395	)	$	38,349,189


	December 31, 2017
	Estimated Useful Lives		Gross Carrying Value		Accumulated Amortization			Net Book Value
Internally developed patents		6-10 years	$	678,340	$	(249,601	)	$	428,739
Acquired licenses		16-20 years		285,000		(237,340	)		47,660

Total intangible assets subject to amortization				963,340		(486,941	)		476,399
IPR&D assets		Indefinite		38,245,871		—			38,245,871

Total			$	39,209,211	$	(486,941	)	$	38,722,270

Changes in the carrying amounts of IPR&D assets for the six months ended June 30, 2018 were:


Balance, beginning of period	$	38,245,871
Foreign currency translation adjustments		(376,903	)

Balance, end of period	$	37,868,968

Amortization expense of intangible assets subject to amortization totaled $14,972 and $13,597 for the three months ended June 30, 2018 and 2017, and $29,446 and $26,152 for the six months ended June 30, 2018 and 2017, respectively. Amortization expense was classified as research and development expenses in the accompanying unaudited condensed consolidated statements of operations and comprehensive loss.

As of June 30, 2018, future estimated amortization expense is as follows:


Years ending December 31,
The remainder of 2018	$	30,816
2019		59,377
2020		45,930
2021		25,371
2022		25,371
2023 and thereafter		293,356

Total	$	480,221

Accrued Expenses and Other Current Liabilities

6 Months Ended

Jun. 30, 2018

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

8. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following:


	June 30, 2018		December 31, 2017
Accrued professional services	$	1,152,368	$	835,326
Accrued payroll and employee benefits		1,263,130		909,455
Accrued interest		1,536		536
Accrued construction costs		2,517		328,384
Accrued research and development costs		2,886,317		1,551,556

Total	$	5,305,868	$	3,625,257

Other Long-Term Liabilities

6 Months Ended

Jun. 30, 2018

Other Long-Term Liabilities

9. Other Long-Term Liabilities

Other long-term liabilities consist of the following:


	June 30, 2018		December 31, 2017
Unvested restricted stock	$	256	$	315
BPI France notes		583,776		599,927
Deferred revenue, long-term portion		149,785		159,671
Deferred rent, long-term portion		1,134,577		386,489
Common stock warrant liability		2,229,431		3,400,869
Embedded derivatives		186,685		27,236

Total	$	4,284,510	$	4,574,507

Beneficial Conversion Feature

6 Months Ended

Jun. 30, 2018

Beneficial Conversion Feature

10. Beneficial Conversion Feature

A summary of the periodic changes in beneficial conversion feature embedded in the redeemable preferred stock as of June 30, 2018 is as follows:


Balance, beginning of period	$	1,338,840
Amount released during the period		(1,231,572	)

Balance, end of period	$	107,268

Embedded Derivatives

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Embedded Derivatives

11. Embedded Derivatives

A summary of the periodic changes in the fair value of the derivative financial instruments embedded in the redeemable preferred stock and Exchange Notes (see Note 5) as of June 30, 2018 is as follows:


	Derivatives embedded in:
	Redeemable Preferred			Exchange Notes
Balance, beginning of period	$	27,236		$	—
Issuance of derivatives with Exchange Notes		—			180,611
Derivative released on redemption of preferred stock		(23,292	)		—
Changes in fair value		2,130			—

Balance, end of period	$	6,074		$	180,611

The fair value used to determine the initial carrying value of the derivative financial instruments embedded in the Exchange Notes were measured using Level 3 inputs and were estimated using the Monte Carlo simulation valuation model. The key assumptions used to estimate the fair value of the embedded redemption and conversion derivatives embedded in the Exchange Notes were as follows:


Estimated annual equity volatility	93.5	%
Default factor	33.0	%
Risk-free interest rate	2.1	%

Warrants

6 Months Ended

Jun. 30, 2018

Federal Home Loan Banks [Abstract]

Warrants

12. Warrants

A summary of warrant activity during the three and six months ended June 30, 2018 and 2017 is as follows:


	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Warrants outstanding, beginning of period		2,350,085			666,546			2,350,085			616,770
Issuances		—			—			—			49,776
Exchanges		(1,593,753	)		—			(1,593,753	)		—
Exercises and conversions		—			(661,888	)		—			(661,888	)

Warrants outstanding, end of period		756,332			4,658			756,332			4,658

For warrants classified as a liability, the following is a summary of the periodic changes in their fair value at June 30, 2018:


Balance, beginning of period	$	3,400,869
Changes in fair value (Monte Carlo simulation valuation)		(1,547,982	)

Balance, March 31, 2018		1,852,887
Warrants settled in First Exchange		(1,259,065	)
Changes in fair value of remaining warrants (Negotiated value)		1,635,609

Balance, end of period	$	2,229,431

Stock-Based Compensation

6 Months Ended

Jun. 30, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

13. Stock-Based Compensation

Stock Options

The Company’s stock option awards generally vest over four years and typically have a contractual life of ten years. At June 30, 2018, there was $1,204,432 of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted-average period of 2.5 years. During the three and six months ended June 30, 2018, the Company issued 55,120 and 286,218 shares of common stock, respectively, as a result of option exercises.

Information related to stock options outstanding at June 30, 2018 is as follows:


	Number of Stock Options		Weighted- average Exercise Price		Weighted- average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding		1,615,380	$	4.03		4.91	$	267,759

Exercisable		702,735	$	5.91		5.48	$	83,042

Expected to vest		912,645	$	2.59		4.47	$	184,717

Restricted Stock

At June 30, 2018, we had unvested restricted stock of 19,168 shares with total unrecognized compensation expense of $3,230, which we expect to recognize over a weighted average period of approximately 2.3 years. During the three and six months ended June 30, 2018, the Company released 2,130 and 4,260 shares of common stock from restriction, respectively, as a result of the vesting of restricted stock.

Stock-based compensation expense

Stock-based compensation expense is classified in the unaudited condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2018 and 2017 as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Research and development	$	108,276	$	81,213	$	197,312	$	156,288
General and administrative		143,850		257,774		411,581		527,800

Total	$	252,126	$	338,987	$	608,893	$	684,088

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes The Company recorded an income tax benefit of $1,497,093 and $2,488,731 for the three and six months ended June 30, 2018, respectively. Income taxes for the six months ended June 30, 2018 included discrete tax benefits of $18,351 related to excess tax benefits associated with share-based compensation, and $271,356 related to a change in estimate. Excluding discrete items, the Company’s annual effective tax rate through June 30, 2018 was 16.81% which includes a $1.5 million benefit due to the Company’s projected 2018 unlimited lived Federal net operating loss (“NOL”) that we have determined to be realizable and a $0.7 million tax benefit due to the ability to carry back Maryland state NOLs generated in 2018. The effective tax rate deviates from the statutory rate primarily due to permanent tax adjustments related to changes in fair value of warrant liability, including loss on exchange described in Note 5. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Act (“SAB 118”) which allows the Company to record provisional amounts during a measurement period not to extend beyond one year from the enactment date. Since the Tax Cuts and Jobs Act (“TCJA”) was passed in December 2017, additional regulatory guidance and accounting interpretation are expected to be released over the next year, and significant data and analysis will be required to finalize amounts recorded pursuant to TCJA. The Company considers the accounting for the deferred tax re-measurements and other items to be incomplete due to the forthcoming guidance and its ongoing analysis of final year-end data and tax positions. The Company expects to complete its analysis within the measurement period in accordance with SAB 118. The Company did not change any provisional estimates recognized in 2017 which would impact the statement of operations. Any adjustments to these amounts will be recorded to current tax expense in 2018 when the analysis is complete.

Contingencies	6 Months Ended
Contingencies	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingencies	15. Contingencies The Company is a party in various other contractual disputes, litigation, and potential claims arising in the ordinary course of business. We do not believe that the resolution of these matters will have a material adverse effect on our financial position or results of operations.

Subsequent Events	6 Months Ended
Subsequent Events	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	16. Subsequent events Refer to Note 5 for a description of the Exchange Agreements entered into on July 11, 2018. The Company was granted a three-month extension on its secured line of credit agreement that originally matured in April 2018. On July 27, 2018, the Company renewed this agreement for a six-month term with an increase to the borrowing capacity from $250,000 to $1,750,000 subject to a minimum liquidity requirement equal to the outstanding balance of the line.

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2018
Accounting Policies [Abstract]
Segment information	Segment information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, our Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. We view our operations and manage our business in one operating segment, the research and development of immunotherapies and vaccines.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In February 2016, FASB issued ASU No. 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 requires a lessee to separate the lease components from the non-lease components in a contract and recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. It also aligns lease accounting for lessors with the revenue recognition guidance in ASU 2014-09. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The standard requires a modified retrospective approach however the FASB recently added a transition option to the leases standard that allows entities to apply the new guidance in the year of transition rather than at the beginning of the earliest period presented. The Company has not elected to early adopt this standard and is currently evaluating the impact the adoption of the standard will have on our financial statements. In June 2018, FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718)—Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”). ASU 2018-07 expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 is effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. We are evaluating what impact, if any, the adoption of ASU 2018-07 may have on our financial statements.

Business Combination (Tables)

6 Months Ended

Jun. 30, 2018

Business Combinations [Abstract]

Schedule of Lists of Various Securities

The following table lists the various securities of PharmAthene which were outstanding as of May 4, 2017 and whose rights and obligations were assumed by the combined entity following the Mergers:


Outstanding PharmAthene common stock		6,883,498
Outstanding PharmAthene stock options		123,003
Outstanding PharmAthene stock warrants		4,658
Per share fair value of PharmAthene common stock	$	6.50
Weighted average per share fair value of PharmAthene stock options, vested and unvested	$	0.26
Per share fair value of PharmAthene stock warrants	$	0.01
Aggregate fair value of consideration	$	44,757,910
Less fair value of unvested common stock options		(15,173	)

Total fair value of consideration	$	44,742,737

Schedule of Purchase Price Allocation

The final adjusted allocation of the purchase consideration is as follows:


Cash and cash equivalents	$	13,684,535
Accounts receivable		1,124,462
Prepaid expenses and other current assets		597,172
Tax refunds receivable		1,556,558
Property and equipment		75,779
IPR&D		22,389,000
Goodwill		16,064,498

Total assets acquired		55,492,004

Accounts payable and accrued expenses		(2,193,785	)
Deferred tax liability		(8,555,482	)

Total liabilities assumed		(10,749,267	)

Net assets acquired	$	44,742,737

Summary of Unaudited Pro Forma Information

The following unaudited pro forma information for the six months ended June 30, 2017 gives effect to the acquisition of PharmAthene as if the Mergers had occurred on January 1, 2017:


Pro forma revenue	$	4,443,495
Pro forma net loss attributable to common stockholders	$	(6,110,625	)
Pro forma weighted-average common shares outstanding, basic and diluted		15,119,716
Pro forma net loss per share attributable to common stockholders, basic and diluted	$	(0.40	)

Exchange Agreements (Tables)

6 Months Ended

Jun. 30, 2018

Summary of Income Statement Effect of Changes in Outstanding Warrants

The following is a summary of the income statement effect of changes in the Company’s outstanding warrants:


	Three Months Ended June 30, 2018		Six Months Ended June 30, 2018
Changes in fair value of warrants		1,635,609		87,627
Loss on warrants exchange June 29, 2018		3,467,935		3,467,935
Transaction Costs		125,147		125,147

Change in fair value of warrant liability, including loss on exchange	$	5,228,691	$	3,680,709

Summary of Key Assumptions Used in Calculating Marketability Discount

This amount is considered a marketability discount calculated based on an analysis of the leak out provision provided for in the exchange agreements. The key assumptions used in calculating the marketability discount were:


Holding period, in years	0.03
Risk free rate	1.77	%
Dividend yield	0	%
Volatility	109.9	%

Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Net Loss Per Share

The following table sets forth the computation of basic and diluted net loss per share:


	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Numerator:
Net loss	$	(9,138,842	)	$	(3,110,382	)	$	(12,312,380	)	$	(7,689,164	)
Less: Preferred stock accretion and dividends		(700,093	)		(44,713	)		(2,591,414	)		(163,069	)

Net loss attributed to common stockholders	$	(9,838,935	)	$	(3,155,095	)	$	(14,903,794	)	$	(7,852,233	)

Denominator:
Weighted-average common shares outstanding, basic and diluted		28,530,423			12,245,701			24,361,010			9,596,423

Net loss per share attributed to common stockholders, basic and diluted	$	(0.34	)	$	(0.26	)	$	(0.61	)	$	(0.82	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share


	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Preferred stock		208,989		—		208,989		—
Common stock warrants		756,332		4,658		756,332		4,658
Common stock options		1,615,380		1,469,659		1,615,380		1,469,659
Restricted stock		19,168		36,962		19,168		36,962

Intangible Assets (Tables)

6 Months Ended

Jun. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets

Our intangible assets consisted of the following:


	June 30, 2018
	Estimated Useful Lives		Gross Carrying Value		Accumulated Amortization			Net Book Value
Internally developed patents		6-10 years	$	711,616	$	(270,869	)	$	440,747
Acquired licenses		16-20 years		285,000		(245,526	)		39,474

Total intangible assets subject to amortization				996,616		(516,395	)		480,221
IPR&D assets		Indefinite		37,868,968		—			37,868,968

Total			$	38,865,584	$	(516,395	)	$	38,349,189


	December 31, 2017
	Estimated Useful Lives		Gross Carrying Value		Accumulated Amortization			Net Book Value
Internally developed patents		6-10 years	$	678,340	$	(249,601	)	$	428,739
Acquired licenses		16-20 years		285,000		(237,340	)		47,660

Total intangible assets subject to amortization				963,340		(486,941	)		476,399
IPR&D assets		Indefinite		38,245,871		—			38,245,871

Total			$	39,209,211	$	(486,941	)	$	38,722,270

Schedule of Changes in Carrying Amounts of IPR&D Assets

Changes in the carrying amounts of IPR&D assets for the six months ended June 30, 2018 were:


Balance, beginning of period	$	38,245,871
Foreign currency translation adjustments		(376,903	)

Balance, end of period	$	37,868,968

Schedule of Future Estimated Amortization Expense

As of June 30, 2018, future estimated amortization expense is as follows:


Years ending December 31,
The remainder of 2018	$	30,816
2019		59,377
2020		45,930
2021		25,371
2022		25,371
2023 and thereafter		293,356

Total	$	480,221

Accrued Expenses and Other Current Liabilities (Tables)

6 Months Ended

Jun. 30, 2018

Payables and Accruals [Abstract]

Summary of Accrued Expenses And Other Current Liabilities

Accrued expenses and other current liabilities consist of the following:


	June 30, 2018		December 31, 2017
Accrued professional services	$	1,152,368	$	835,326
Accrued payroll and employee benefits		1,263,130		909,455
Accrued interest		1,536		536
Accrued construction costs		2,517		328,384
Accrued research and development costs		2,886,317		1,551,556

Total	$	5,305,868	$	3,625,257

Other Long-Term Liabilities (Tables)

6 Months Ended

Jun. 30, 2018

Summary of Other Long-Term Liabilities

Other long-term liabilities consist of the following:


	June 30, 2018		December 31, 2017
Unvested restricted stock	$	256	$	315
BPI France notes		583,776		599,927
Deferred revenue, long-term portion		149,785		159,671
Deferred rent, long-term portion		1,134,577		386,489
Common stock warrant liability		2,229,431		3,400,869
Embedded derivatives		186,685		27,236

Total	$	4,284,510	$	4,574,507

Beneficial Conversion Feature (Tables)

6 Months Ended

Jun. 30, 2018

Summary of Periodic Changes in Beneficial Conversion Feature Embedded in the Redeemable Preferred Stock

A summary of the periodic changes in beneficial conversion feature embedded in the redeemable preferred stock as of June 30, 2018 is as follows:


Balance, beginning of period	$	1,338,840
Amount released during the period		(1,231,572	)

Balance, end of period	$	107,268

Embedded Derivatives (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Summary of Periodic Changes in Fair Value of Derivative Financial Instruments Embedded


	Derivatives embedded in:
	Redeemable Preferred			Exchange Notes
Balance, beginning of period	$	27,236		$	—
Issuance of derivatives with Exchange Notes		—			180,611
Derivative released on redemption of preferred stock		(23,292	)		—
Changes in fair value		2,130			—

Balance, end of period	$	6,074		$	180,611

Assumptions Used to Estimate Fair Value of Embedded Redemption and Conversion Derivative Financial Instruments Embedded


Estimated annual equity volatility	93.5	%
Default factor	33.0	%
Risk-free interest rate	2.1	%

Warrants (Tables)

6 Months Ended

Jun. 30, 2018

Federal Home Loan Banks [Abstract]

Summary of Warrant Activity

A summary of warrant activity during the three and six months ended June 30, 2018 and 2017 is as follows:


	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Warrants outstanding, beginning of period		2,350,085			666,546			2,350,085			616,770
Issuances		—			—			—			49,776
Exchanges		(1,593,753	)		—			(1,593,753	)		—
Exercises and conversions		—			(661,888	)		—			(661,888	)

Warrants outstanding, end of period		756,332			4,658			756,332			4,658

Summary of Periodic Changes in Fair Value of Warrant Liability

For warrants classified as a liability, the following is a summary of the periodic changes in their fair value at June 30, 2018:


Balance, beginning of period	$	3,400,869
Changes in fair value (Monte Carlo simulation valuation)		(1,547,982	)

Balance, March 31, 2018		1,852,887
Warrants settled in First Exchange		(1,259,065	)
Changes in fair value of remaining warrants (Negotiated value)		1,635,609

Balance, end of period	$	2,229,431

Tabular disclosure of warrants or rights issued. Warrants and rights outstanding are derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. The main difference between warrants and call options is that warrants are issued and guaranteed by the company, whereas options are exchange instruments and are not issued by the company. Also, the lifetime of a warrant is often measured in years, while the lifetime of a typical option is measured in months. Disclose the title of issue of securities called for by warrants and rights outstanding, the aggregate amount of securities called for by warrants and rights outstanding, the date from which the warrants or rights are exercisable, and the price at which the warrant or right is exercisable.

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

Schedule of Information Related to Stock Options Outstanding

Information related to stock options outstanding at June 30, 2018 is as follows:


	Number of Stock Options		Weighted- average Exercise Price		Weighted- average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding		1,615,380	$	4.03		4.91	$	267,759

Exercisable		702,735	$	5.91		5.48	$	83,042

Expected to vest		912,645	$	2.59		4.47	$	184,717

Schedule of Stock-based Compensation Expense


	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Research and development	$	108,276	$	81,213	$	197,312	$	156,288
General and administrative		143,850		257,774		411,581		527,800

Total	$	252,126	$	338,987	$	608,893	$	684,088

Nature of Business and Basis of Presentation - Additional Information (Detail) - Merger Agreement [Member]	6 Months Ended
	Jun. 30, 2018
Business And Basis Of Presentation [Line Items]
Agreement of reorganization and merger date	Jan. 18, 2017
Merger Sub Corp I Inc and Mustang Merger Sub II LLC [Member]
Business And Basis Of Presentation [Line Items]
Business acquisition, percentage of voting interest acquired	100.00%

Going Concern - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ (9,138,842)	$ (3,110,382)	$ (12,312,380)	$ (7,689,164)
Cash used to fund operations			(3,210,558)	$ (11,149,228)
Accumulated deficit	$ (89,997,219)		$ (89,997,219)		$ (77,684,839)

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

Summary of Significant Accounting Policies - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2018 Segment
Accounting Policies [Abstract]
Number of operating segments	1

Business Combination - Additional Information (Detail)		3 Months Ended			6 Months Ended		12 Months Ended
Business Combination - Additional Information (Detail)	May 04, 2017 USD ($) shares	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Business Acquisition [Line Items]
Share exchange ratio					1-for-1 basis
Debt converted in to equity	316,734
Conversion of stock \| shares	6,883,498
Transaction costs	$ 2,183,671
Increase in goodwill from recorded adjustments					$ 490,676
Discount rate	23.00%
Goodwill			$ 0
Goodwill impairment charge			$ 490,676		490,676
Revenue		$ 2,417,140		$ 3,037,973	5,108,121	$ 3,337,544
Net Income		(9,138,842)		$ (3,110,382)	(12,312,380)	$ (7,689,164)
Change in fair value of derivatives					90,191
Interest expense convertible note					722,029
Restricted Stock Units (RSUs) [Member]
Business Acquisition [Line Items]
Conversion of stock \| shares	39,758
Series B Preferred Stock [Member]
Business Acquisition [Line Items]
Conversion of preferred stock	$ 599,285
Common Stock Class A [Member]
Business Acquisition [Line Items]
Common stock issued \| shares	6,883,498
United States [Member]
Business Acquisition [Line Items]
Operating loss carryforwards		$ 965,583			$ 965,583
Operating loss carryforwards, expiration date					Jan. 01, 2023
Reversal of Acquisition Related Costs [Member]
Business Acquisition [Line Items]
Nonrecurring pro forma adjustments					$ 2,341,279
Common Stock Warrants [Member]
Business Acquisition [Line Items]
Conversion of stock \| shares	660,715
PharmAthene [Member]
Business Acquisition [Line Items]
Reverse stock split of common stock	0.749106
Equity interests acquired	58.20%
Total fair value of consideration	$ 44,742,737
Outstanding unvested options \| shares	7,569
Stock options estimated fair value	$ 15,173
Increase tax refund receivable due to adjustments to the allocation of the purchase consideration							$ 44,700
Reduce deferred tax liability due to adjustments to the allocation of the purchase consideration							4,535
Increase in goodwill due to adjustments to the allocation of the purchase consideration							$ 49,235
Change in tax rate					35.00%		34.00%
Goodwill	$ 16,064,498
Revenue					$ 1,240,369
Net Income					20,880
Nonrecurring pro forma adjustments					(6,110,625)
PharmAthene [Member] \| Stock Compensation Expense [Member]
Business Acquisition [Line Items]
Nonrecurring pro forma adjustments					$ 66,367

Business Combination - Schedule of Lists of Various Securities (Detail) - USD ($)	May 04, 2017	Jun. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Outstanding PharmAthene common stock		37,363,965	18,103,691
Outstanding PharmAthene stock options			1,615,380
Weighted average per share fair value of PharmAthene stock options, vested and unvested			$ 4.03
PharmAthene [Member]
Business Acquisition [Line Items]
Outstanding PharmAthene common stock	6,883,498
Outstanding PharmAthene stock options	123,003
Outstanding PharmAthene stock warrants	4,658
Per share fair value of PharmAthene common stock	$ 6.50
Weighted average per share fair value of PharmAthene stock options, vested and unvested	0.26
Per share fair value of PharmAthene stock warrants	$ 0.01
Aggregate fair value of consideration	$ 44,757,910
Less fair value of unvested common stock options	(15,173)
Total fair value of consideration	$ 44,742,737

Business Combination - Schedule of Purchase Price Allocation (Detail) - USD ($)	Mar. 31, 2018	May 04, 2017
Business Acquisition [Line Items]
Goodwill	$ 0
PharmAthene [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		$ 13,684,535
Accounts receivable		1,124,462
Prepaid expenses and other current assets		597,172
Tax refunds receivable		1,556,558
Property and equipment		75,779
IPR&D		22,389,000
Goodwill		16,064,498
Total assets acquired		55,492,004
Accounts payable and accrued expenses		(2,193,785)
Deferred tax liability		(8,555,482)
Total liabilities assumed		(10,749,267)
Net assets acquired		$ 44,742,737

Business Combination - Summary of Unaudited Pro Forma Information (Detail) - PharmAthene [Member]	6 Months Ended
	Jun. 30, 2018 USD ($) $ / shares shares
Business Acquisition [Line Items]
Pro forma revenue	$ 4,443,495
Pro forma net loss attributable to common stockholders	$ (6,110,625)
Pro forma weighted-average common shares outstanding, basic and diluted \| shares	15,119,716
Pro forma net loss per share attributable to common stockholders, basic and diluted \| $ / shares	$ (0.40)

Exchange Agreements - Additional Information (Detail)		1 Months Ended			6 Months Ended
Exchange Agreements - Additional Information (Detail)	Jun. 29, 2018 USD ($) $ / shares shares	Aug. 30, 2018 shares	Jun. 30, 2018 USD ($) $ / shares shares	Mar. 31, 2018 USD ($)	Jun. 30, 2018 USD ($) $ / shares shares	Jun. 29, 2018 USD ($) $ / shares shares	Dec. 31, 2017 $ / shares	Jun. 30, 2017 shares
Class of Warrant or Right [Line Items]
Conversion of warrant to common stock \| shares	1,593,753		1,593,753		1,593,753	1,593,753
Stock price per share \| $ / shares			$ 0.0001		$ 0.0001		$ 0.0001
Deemed dividend			$ 56,792		$ 56,792
Exchange consideration discounted percentage						5
Convertible Debt [Member]
Class of Warrant or Right [Line Items]
Convertible note discount			180,611		180,611
Carrying value of note			1,319,389		1,319,389
Debt issuance costs			$ 58,172		$ 58,172
First Exchange Warrants [Member]
Class of Warrant or Right [Line Items]
Conversion of warrant to common stock \| shares			2,205,883		2,205,883
Issuance of common stock for the exchange of warrants \| shares	5,030,991
Stock price per share \| $ / shares	$ 0.42					$ 0.42
Convertible notes principal balance	$ 1,500,000		$ 1,500,000		$ 1,500,000	$ 1,500,000
Cash proceeds from common stock	$ 1,100,000
Proceeds from exchange of warrants					4,727,000
Converted value in excess of principal				$ 3,467,935
Loss on exchange of warrant					3,593,082
Transaction costs					$ 125,147
Convertible debt, interest rate in event of default					112.00%
Convertion price per share \| $ / shares			$ 0.68		$ 0.68
Weighted average prices of common stock					75.00%
Weighted average price per share of common stock \| $ / shares					$ 0.15
Interest payable			1.00%		1.00%
Number of trading days			0		0
First Exchange Warrants [Member] \| Series B Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Face value of preferred stock			$ 2,364,044		$ 2,364,044
Second Warrants Exchange [Member]
Class of Warrant or Right [Line Items]
Number unexchanged warrants \| shares			756,332		756,332
Unexchanged warrants			$ 2,229,431		$ 2,229,431
Warrants exercise price \| $ / shares			$ 2.97		$ 2.97
Second Warrants Exchange [Member] \| Series B Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares issued \| shares					963,711
Proceeds from issuance of warrants					$ 22,241
Second Warrants Exchange [Member] \| Subsequent Event [Member]
Class of Warrant or Right [Line Items]
Conversion of warrant to common stock \| shares		675,679
Number of shares issued \| shares		4,351,136

Exchange Agreements - Summary of Income Statement Effect of Changes in Outstanding Warrants (Detail) - Common Stock Warrants [Member] - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Class of Warrant or Right [Line Items]
Changes in fair value of warrants	$ 1,635,609	$ 87,627
Loss on warrants exchange June 29, 2018	3,467,935	3,467,935
Transaction Costs	125,147	125,147
Change in fair value of warrant liability, including loss on exchange	$ 5,228,691	$ 3,680,709

Exchange Agreements - Summary of Key Assumptions Used in Calculating Marketability Discount (Detail)	6 Months Ended
	Jun. 30, 2018
Class of Warrant or Right [Line Items]
Holding period, in years	11 days
Risk Free Rate Member]
Class of Warrant or Right [Line Items]
Measurement input	1.77%
Dividend Yield [Member]
Class of Warrant or Right [Line Items]
Measurement input	0.00%
Volatility [Member]
Class of Warrant or Right [Line Items]
Measurement input	109.90%

Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Net loss	$ (9,138,842)	$ (3,110,382)	$ (12,312,380)	$ (7,689,164)
Less: Preferred stock accretion and dividends	(700,093)	(44,713)	(2,591,414)	(163,069)
Net loss attributed to common stockholders	$ (9,838,935)	$ (3,155,095)	$ (14,903,794)	$ (7,852,233)
Denominator:
Weighted-average common share outstanding, basic and diluted	28,530,423	12,245,701	24,361,010	9,596,423
Net loss per share attributable to common stockholders, basic and diluted	$ (0.34)	$ (0.26)	$ (0.61)	$ (0.82)

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	1,615,380	1,469,659	1,615,380	1,469,659
Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	208,989		208,989
Common Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	756,332	4,658	756,332	4,658
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	19,168	36,962	19,168	36,962

Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Schedule Of Intangible Assets [Line Items]
Total intangible assets, Gross Carrying Value	$ 38,865,584	$ 39,209,211
Intangible assets subject to amortization, Gross Carrying Value	996,616	963,340
Intangible assets subject to amortization, Accumulated Amortization	(516,395)	(486,941)
Intangible assets subject to amortization, Net Book Value	480,221	476,399
Total intangible assets, Net Book Value	38,349,189	38,722,270
IPR&D [Member]
Schedule Of Intangible Assets [Line Items]
Intangible assets, Net Book Value	37,868,968	38,245,871
Internally Developed Patents [Member]
Schedule Of Intangible Assets [Line Items]
Intangible assets subject to amortization, Gross Carrying Value	711,616	678,340
Intangible assets subject to amortization, Accumulated Amortization	(270,869)	(249,601)
Intangible assets subject to amortization, Net Book Value	$ 440,747	$ 428,739
Internally Developed Patents [Member] \| Minimum [Member]
Schedule Of Intangible Assets [Line Items]
Estimated Useful Lives	6 years	6 years
Internally Developed Patents [Member] \| Maximum [Member]
Schedule Of Intangible Assets [Line Items]
Estimated Useful Lives	10 years	10 years
Acquired Licenses [Member]
Schedule Of Intangible Assets [Line Items]
Intangible assets subject to amortization, Gross Carrying Value	$ 285,000	$ 285,000
Intangible assets subject to amortization, Accumulated Amortization	(245,526)	(237,340)
Intangible assets subject to amortization, Net Book Value	$ 39,474	$ 47,660
Acquired Licenses [Member] \| Minimum [Member]
Schedule Of Intangible Assets [Line Items]
Estimated Useful Lives	16 years	16 years
Acquired Licenses [Member] \| Maximum [Member]
Schedule Of Intangible Assets [Line Items]
Estimated Useful Lives	20 years	20 years

Intangible Assets - Schedule of Changes in Carrying Amounts of IPR&D Assets (Detail) - IPR&D [Member]	6 Months Ended
	Jun. 30, 2018 USD ($)
Indefinite-lived Intangible Assets [Line Items]
IPR&D Balance, beginning of period	$ 38,245,871
IPR&D, Foreign currency translation adjustments	(376,903)
IPR&D Balance, end of period	$ 37,868,968

Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 14,972	$ 13,597	$ 29,446	$ 26,152

Intangible Assets - Schedule of Future Estimated Amortization Expense (Detail) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
The remainder of 2018	$ 30,816
2019	59,377
2020	45,930
2021	25,371
2022	25,371
2023 and thereafter	293,356
Intangible assets subject to amortization, Net Book Value	$ 480,221	$ 476,399

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Accrued Liabilities and Other Liabilities [Abstract]
Accrued professional services	$ 1,152,368	$ 835,326
Accrued payroll and employee benefits	1,263,130	909,455
Accrued interest	1,536	536
Accrued construction costs	2,517	328,384
Accrued research and development costs	2,886,317	1,551,556
Total	$ 5,305,868	$ 3,625,257

Other Long-Term Liabilities - Summary of Other Long-Term Liabilities (Detail) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unvested restricted stock	$ 256	$ 315
Deferred revenue, long-term portion	149,785	159,671
Deferred rent, long-term portion	1,134,577	386,489
Common stock warrant liability	2,229,431	3,400,869
Embedded derivatives	186,685	27,236
Total	4,284,510	4,574,507
BPI France Notes [Member]
Debt Instrument [Line Items]
BPI France notes	$ 583,776	$ 599,927

Beneficial Conversion Feature - Summary of Periodic Changes in Beneficial Conversion Feature Embedded in the Redeemable Preferred Stock (Detail) - Series B Redeemable Convertible Preferred Stock [Member]	6 Months Ended
	Jun. 30, 2018 USD ($)
Conversion of Stock [Line Items]
Balance, beginning of period	$ 1,338,840
Amount released during the period	(1,231,572)
Balance, end of period	$ 107,268

Embedded Derivatives - Summary of Periodic Changes in Fair Value of Derivative Financial Instruments Embedded (Detail)	6 Months Ended
	Jun. 30, 2018 USD ($)
Redeemable Preferred Stock [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ 27,236
Derivative released on redemption of preferred stock	(23,292)
Changes in fair value	2,130
Balance, end of period	6,074
Exchange Notes [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Issuance of derivatives with Exchange Notes	180,611
Balance, end of period	$ 180,611

Embedded Derivatives - Assumptions Used to Estimate Fair Value of Embedded Redemption and Conversion Derivative Financial Instruments Embedded (Detail) - Level 3 [Member]	Jun. 30, 2018
Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Estimated fair value assumptions	93.5
Default Factor [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Estimated fair value assumptions	33.0
Risk Free Rate Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Estimated fair value assumptions	2.1

Warrants - Summary of Warrant Activity (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 29, 2018
Warrants and Rights Note Disclosure [Abstract]
Warrants outstanding, beginning of period	2,350,085	666,546	2,350,085	616,770
Issuances				49,776
Exchanges	(1,593,753)		(1,593,753)		(1,593,753)
Exercises and conversions		(661,888)		(661,888)
Warrants outstanding, end of period	756,332	4,658	756,332	4,658

Warrants - Summary of Periodic Changes in Fair Value of Warrant Liability (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Changes in fair value	$ 5,228,691		$ 3,680,709
Level 3 [Member] \| Common Stock Warrants [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Balance, beginning of period	1,852,887	$ 3,400,869	3,400,869
Warrants settled in First Exchange	(1,259,065)
Changes in fair value	1,635,609	(1,547,982)
Balance, end of period	$ 2,229,431	$ 1,852,887	$ 2,229,431

Stock-Based Compensation - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2018 USD ($) shares	Jun. 30, 2018 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued as result of option exercises		702,735
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting Period		4 years
Stock option expiration Period		10 years
Unrecognized compensation cost, stock options \| $	$ 1,204,432	$ 1,204,432
Unrecognized stock-based compensation expense, period for recognition		2 years 6 months
Common stock issued as result of option exercises	55,120	286,218
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense, period for recognition		2 years 3 months 19 days
Unrecognized compensation expense \| $	$ 3,230	$ 3,230
Unvested restricted stock, shares	19,168	19,168
Common stock issued as result of vesting of restricted stock	2,130	4,260

Stock-Based Compensation - Schedule of Information Related to Stock Options Outstanding (Detail)	6 Months Ended
	Jun. 30, 2018 USD ($) $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Stock Options, Outstanding \| shares	1,615,380
Number of Stock Options, Exercised \| shares	702,735
Number of Stock Options, Expected to vest \| shares	912,645
Weighted-average Exercise Price, Outstanding \| $ / shares	$ 4.03
Weighted-average Exercise Price, Exercised \| $ / shares	5.91
Weighted-average Exercise Price, Expected to vest \| $ / shares	$ 2.59
Weighted-average Remaining Contractual Term, Outstanding	4 years 10 months 28 days
Weighted-average Remaining Contractual Term, Exercisable	5 years 5 months 23 days
Weighted-average Remaining Contractual Term, Expected to vest	4 years 5 months 20 days
Weighted-average Intrinsic Value, Outstanding \| $	$ 267,759
Weighted-average Intrinsic Value, Exercisable \| $	83,042
Weighted-average Intrinsic Value, Expected to vest \| $	$ 184,717

Stock-Based Compensation - Schedule of Stock-based Compensation Expense (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock based compensation expense	$ 252,126	$ 338,987	$ 608,893	$ 684,088
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock based compensation expense	108,276	81,213	197,312	156,288
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock based compensation expense	$ 143,850	$ 257,774	$ 411,581	$ 527,800

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Taxes [Line Items]
Income tax benefit	$ (1,497,093)	$ (993,709)	$ (2,488,731)	$ (993,709)
Excess tax benefits associated with share-based compensation			18,351
Change in estimate			$ 271,356
Effective tax rate			16.81%
United States Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforward	1,500,000		$ 1,500,000
State [Member] \| Maryland [Member]
Income Taxes [Line Items]
Net operating loss carryforward	$ 700,000		$ 700,000

Subsequent Events - Additional Information (Detail) - USD ($)	Jul. 27, 2018	Jul. 26, 2018
Subsequent Event [Member]
Subsequent Event [Line Items]
Increase to the borrowing capacity	$ 1,750,000	$ 250,000

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.