Equity-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Equity-Based Compensation

Summary of allocation of equity-based compensation

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

	Year Ended
	December 31,
	2019		2018
Research and development expense	$	2,425	$	1,661
General and administrative expense		5,547		3,550
	$	7,972	$	5,211

Summary of restricted common stock activity

		Weighted
		Average Fair
		Value per Share
	Number of Shares	at Issuance
Restricted common stock as of December 31, 2018	664,174	$	5.77
Granted	—	$	—
Vested	(357,604)	$	5.77
Forfeited	(4,210)	$	5.77
Restricted common stock as of December 31, 2019	302,360	$	5.77

Summary of stock option activity

				Weighted
		Weighted		Average
	Number of	Average		Remaining	Aggregate
	Shares	Exercise Price		Contractual Term	Intrinsic Value
				(in years)	(in thousands)
Outstanding as of December 31, 2018	1,627,947	$	10.86	9.26	$	19,831
Granted	1,034,825	$	15.07
Exercised	(129,431)	$	7.06
Cancelled	(131,959)	$	15.46
Outstanding as of December 31, 2019	2,401,382	$	12.63	8.36	$	6,523
Options exercisable as of December 31, 2019	787,537	$	11.17	7.40	$	2,902

Schedule of fair value assumptions

Risk-free interest rate	2.31	%
Expected dividend yield	0.0	%
Expected term (years to liquidity)	6.20
Expected volatility	79.50	%