Equity-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2018

Equity-Based Compensation

Schedule of allocation of equity-based compensation in the consolidated statements of operations

The Company recorded equity-based compensation expense related to all equity-based awards for employees and nonemployees, which was allocated as follows in the consolidated statements of operations (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2018		2017		2018		2017
Research and development expense	$	453	$	145	$	1,240	$	370
General and administrative expense		1,033		56		1,817		319
	$	1,486	$	201	$	3,057	$	689

Summary of restricted common stock activity

		Weighted
		Average Fair
		Value per Share
	Number of Shares	at Issuance
Restricted common stock as of December 31, 2017	1,220,085	$	5.77
Granted	—	$
Vested	(353,549)	$	5.77
Forfeited	(3,219)	$	5.77
Restricted common stock as of September 30, 2018	863,317	$	5.77

Summary of stock option activity

		Weighted		Weighted
	Number of	Average Exercise		Average Remaining	Aggregate Intrinsic
	Shares	Price		Contractual Term	Value
				(in years)	(in thousands)
Outstanding as of December 31, 2017	—	$	—	—	$	—
Granted	1,509,705		9.64	—		—
Exercised	(449)		5.77	—		—
Forfeited	(8,525)		7.73	—		—
Outstanding as of September 30, 2018	1,500,731	$	9.65	9.52	$	24,157
Options exercisable as of September 30, 2018	119,066	$	8.73	9.47	$	2,017

Schedule of fair value assumptions

	Nine Months Ended September 30, 2018
	Employees		Non-Employees
Risk-free interest rate	2.76	%	3.05	%
Expected dividend yield	—	%	-	%
Expected term (years to liquidity)	6.12		9.39
Expected volatility	81.58	%	76.80	%