Share-Based Payment Awards (Tables)

3 Months Ended

Mar. 31, 2023

Share-Based Payment Arrangement [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 three months ended March 31, 2023:

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life		Aggregate Intrinsic Value
						(in years)		(in thousands)
Outstanding at January 1, 2023		4,082,555		$	13.79
Granted		2,003,895			3.27
Exercised		—			—
Forfeited		(17,354	)		9.04
Expired		—			—
Outstanding at March 31, 2023		6,069,096		$	10.33		8.33	$	6
Exercisable at March 31, 2023		2,075,691		$	16.73		6.63	$	—

Schedule of Key Assumptions Used

In determining the grant date fair value of option awards during the three months ended March 31, 2023, the Company applied the Black-Scholes option pricing model based on the following key assumptions:

Option life (in years)	6.08
Stock volatility	78% - 79%
Risk-free interest rate	3.54% - 3.95%
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 three months ended March 31, 2023 (in thousands except per share amount):

	Three Months
	Ended
	March 31, 2023
Weighted average grant date fair value per share	$	2.28
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 three months ended March 31, 2023:

	Number of Restricted Stock Units			Weighted Average Grant Date Fair Value
Nonvested at January 1, 2023		509,170		$	10.81
Granted		—			—
Vested		(196,102	)		11.12
Forfeited		(2,051	)		10.74
Nonvested at March 31, 2023		311,017		$	10.62

Compensation Expense from Stock-Based Payment Awards

The Company’s condensed consolidated statements of comprehensive loss included total compensation expense from stock-based payment awards for the three months ended March 31, 2023 and 2022, respectively, as follows (in thousands):

	Three Months Ended March 31,
	2023		2022
Compensation expense included in:
Research and development	$	1,240	$	1,473
Sales and marketing		430		409
General and administrative		1,380		1,595
	$	3,050	$	3,477