Share-based compensation (Tables)

3 Months Ended

Mar. 31, 2021

Share-based compensation

Schedule of Stock-based compensation expense

Share-based compensation expense recorded as research and development and general and administrative expenses in the condensed statements of operations is as follows:

	Three Months Ended March 31,
In thousands)	2021		2020
General and administrative	$	171	$	99
Research and development		154		47
	$	325	$	146

Weighted average assumptions used in option-pricing

The weighted average assumptions used in the Black-Scholes option-pricing model for stock options granted were:

	Three Months Ended March 31,
	2021			2020
Expected volatility		83.5	%		80.0	%
Risk-free interest rate		1.1	%		0.8	%
Expected term (in years)		6.1			5.6
Expected dividend yield		—			—
Fair value of common stock	$	31.83		$	1.62

Summary of option activity

A summary of option activity during the three months ended March 31, 2021 is as follows:

				Weighted
		Weighted		average
		average		remaining
	Number of	exercise price		contractual
	shares	per share		term (years)
Outstanding at January 1, 2021	1,472,840	$	3.14	8.51
Granted	183,000	$	31.83
Forfeited	(5,501)	$	8.10
Exercised	(14,270)	$	0.39
Outstanding at March 31, 2021	1,636,069	$	6.36	8.42
Exercisable at March 31, 2021	480,790	$	1.42	7.70
Vested or expected to vest at March 31, 2021	1,636,069	$	6.36	8.42