Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Summary of Stock Option Activity

The following table sets forth the stock option activity for the nine months ended September 30, 2021:

	​Number of shares			​Weighted average exercise price		Weighted average contractual term		​Aggregate intrinsic value
Outstanding at December 31, 2020		3,725,648		$	16.36
Granted		1,279,152			62.09
Exercised		(198,121	)		16.71
Forfeited		(210,854	)		41.68
Expired		(983	)		79.19
Outstanding at September 30, 2021		4,594,842		$	27.90		7.2	$	184,602,602
Vested and expected to vest at September 30, 2021		4,588,673		$	27.94		7.2	$	184,194,454
Exercisable at September 30, 2021		2,784,567		$	14.26		5.6	$	149,261,931

Schedule of RSU Activity

The following table sets forth the RSU activity for the nine months ended September 30, 2021:

	Number of shares			Weighted average grant date fair value
Outstanding at December 31, 2020		136,067		$	36.83
Granted		203,629			49.28
Vested		(8,815	)		45.12
Forfeited		(28,880	)		45.59
Outstanding at September 30, 2021		302,001		$	44.15

Schedule of Stock-Based Compensation Expense Recognized

Stock-based compensation expense recognized for the three and nine months ended September 30, 2021 and 2020 was allocated as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Research and development	$	1,979,765	$	860,744	$	5,816,664	$	2,532,649
General and administrative	$	3,745,452		2,008,074		9,095,892		6,617,724
Total	$	5,725,217	$	2,868,818	$	14,912,556	$	9,150,373

Schedule of Warrant Activity

The following table summarizes warrant activity for the nine months ended September 30, 2021:

			Weighted
			average
	Number of warrants		exercise price
Outstanding at December 31, 2020		15,541	$	80.43
Issued		—		—
Exercised		—		—
Outstanding at September 30, 2021		15,541	$	80.43