Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Estimate of the Fair Value of Stock Option

The following assumptions were used to estimate the fair value of stock option for the six months ended June 30, 2020 and 2019:

	Six Months Ended June 30,
	2020		2019
	(unaudited)
Risk-free interest rate		0.90%		2.0% - 2.1%
Expected dividend yield		—		—
Expected term in years		7.0		6.38 - 10.00
Expected volatility		70.0%		80.0%

Summary of Stock Option Activity

The following table summarizes stock option activity during the six months ended June 30, 2020:

	Stock Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2019		2,041,205		$	9.52		7.7	$	7,857
Options granted		867,031			14.81
Option exercised		(111,936	)		7.73
Options forfeited		(200,213	)		12.01
Outstanding as of June 30, 2020 (unaudited)		2,596,087		$	11.17		7.8	$	17,816
Options vested and exercisable as of June 30, 2020 (unaudited)		1,138,429		$	8.34		6.1	$	11,037

Schedule of RSA Activity

The Company’s RSA activity for the six months ended June 30, 2020 was as follows:

	Number of Shares			Weighted Average Grant Price
Unvested as of December 31, 2019		—		$	—
Granted		14,945			14.81
Vested		(14,945	)		14.81
Unvested as of June 30, 2020 (unaudited)		—		$	—

Summary of the Total Stock-Based Compensation Expense for the Stock Options and RSAs Recorded in the Condensed Consolidated Statements of Operations and Comprehensive Loss

The following table summarizes the total stock-based compensation expense for the stock options and RSAs recorded in the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2020 and 2019 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
	(unaudited)				(unaudited)
Cost of products sold	$	58	$	54	$	166	$	106
Research and development		167		150		378		292
Selling, general and administrative		932		599		2,354		964
Total stock-based compensation	$	1,157	$	803	$	2,898	$	1,362