Share-Based Payment Awards (Tables)

6 Months Ended

Jun. 30, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Option Activity Under Plan

The following table provides a reconciliation of stock option activity under the Company’s equity incentive plans and for inducement awards for the six months ended June 30, 2020:

						Weighted
				Weighted		Average
				Average		Remaining		Aggregate
	Number			Exercise		Contractual		Intrinsic
	of Options			Price		Life		Value
						(in years)		(in thousands)
Outstanding at January 1, 2020		10,909,800		$	2.52
Granted		3,613,897			1.30
Exercised		—			—
Forfeited		(437,482	)		1.84
Expired		(413,865	)		3.70
Outstanding at June 30, 2020		13,672,350		$	2.18		7.93	$	—
Exercisable at June 30, 2020		5,689,656		$	2.74		6.47	$	—

Schedule of Key Assumptions Used

In determining the grant date fair value of option awards during the six months ended June 30, 2020, the Company applied the Black-Scholes option pricing model based on the following key assumptions:

Option life (in years)	5.5-6.02
Stock volatility	63.85%-66.9%
Risk-free interest rate	0.51%-2.51%
Expected dividends	0.0%

Summary of Information about Stock Options

The following table summarizes information about employee, non-executive director and external consultant stock options for the six months ended June 30, 2020 (in thousands, except per share amount):

	Six Months Ended
	June 30, 2020
Weighted-average grant date fair value per share	$	0.76
Total cash received from exercise of stock options		—
Total intrinsic value of stock options exercised		—

Summary of Restricted Stock Unit Activity

The following table provides a reconciliation of RSU activity under the 2016 Plan for the six months ended June 30, 2020:

				Weighted
	Number of			Average
	Restricted			Grant Date
	Stock Units			Fair Value
Nonvested at January 1, 2020		786,899		$	1.83
Granted		1,437,750			1.29
Vested		(697,505	)		1.53
Forfeited		(63,623	)		1.85
Nonvested at June 30, 2020		1,463,521		$	1.44

Compensation Expense from Stock-Based Payment Awards

The Company’s consolidated statements of comprehensive loss included total compensation expense from stock-based payment awards for each of the three and six months ended June 30, 2020 and 2019, respectively, as follows (in thousands):

	Three Months Ended June 30,					Six Months Ended June 30,
	2020			2019		2020		2019
Compensation expense included in:
Research and development	$	(49	)	$	268	$	214	$	664
Sales and marketing		141			179		393		323
General and administrative		643			1,049		1,288		1,747
	$	735		$	1,496	$	1,895	$	2,734