In February 2020, the Company adopted the 2020 Equity Incentive Plan, or the 2020 Plan. The 2020 Plan became effective on February 11, 2020. The 2020 Plan provides for a variety of stock-based compensation awards, including stock options, stock appreciation rights, or SARs, restricted stock awards, restricted stock unit awards, performance bonus awards, performance stock unit awards, dividend equivalents, or other stock or cash based awards. Under the 2020 Plan, the Company generally grants stock-based awards with service-based vesting conditions only. Options granted typically vest over a four-year period, but may be granted with different vesting terms.

Following the effectiveness of the 2020 Plan, the Company will not make any further grants under the 2014 Equity Incentive Plan, or the 2014 Plan. However, the 2014 Plan will continue to govern the terms and conditions of the outstanding awards granted under it. Shares of common stock subject to awards granted under the 2014 Plan that are forfeited or lapse unexercised and which following the effective date of the 2020 Plan are not issued under the 2014 Plan will be available for issuance under the 2020 Plan.

As of March 31, 2020, there were 5,110,075 shares of common stock reserved for issuance pursuant to the 2020 Plan.

In December 2014, the Company adopted the 2014 Plan which provided for the Company to issue restricted common stock, or to grant incentive stock options or nonqualified stock options for the purchase of common stock, to employees, members of the Board of Directors and consultants of the Company under terms and provisions established by the Board of Directors. The Company generally granted stock-based awards with service-based vesting conditions only. Options granted typically vest over a four-year period but may be granted with different vesting terms.

The following summarizes option activity under both the 2020 Plan and the 2014 Plan:

	Number of Shares underlying options			Weighted- average exercise price		Weighted- average remaining contractual term		Aggregate intrinsic value
						(in years)		(in thousands)
Balance, December 31, 2019		4,918,299		$	3.59		8.96	$	51,276
Options granted		661,122			17.86
Options exercised		(11,097	)		2.48
Options cancelled		—			—
Balance, March 31, 2020		5,568,324		$	5.29		8.85	$	92,572
Options vested and expected to vest as of March 31, 2020		5,568,324		$	5.29		8.85	$	92,572
Options vested and exercisable as of March 31, 2020		1,582,478		$	2.33		7.98	$	30,990

As of March 31, 2020, there was $22.2 million of unrecognized stock-based compensation expense related to unvested stock options that is expected to be recognized over a weighted-average period of 3.0 years.

In February 2020, the Company adopted the 2020 Employee Stock Purchase Plan, or the 2020 ESPP. Under the 2020 ESPP, employees have the ability to purchase shares of our common stock through payroll deductions at a discount during a series of offering periods of 24 months, each comprised of four six-month purchase periods. The purchase price will be the lower of 85% of the closing trading price per share of the Company’s common stock on the first day of an offering period in which an employee is enrolled or 85% of the closing trading price per share on the purchase date, which will occur on the last trading day of each purchase period.

The Company has reserved for issuance 528,959 shares of common stock pursuant to the 2020 ESPP. As of March 31, 2020, no offering periods have commenced under the 2020 ESPP.

	Three Months Ended March 31,
	2020		2019
	(in thousands)
Research and development	$	893	$	208
General and administrative		674		195
Total	$	1,567	$	403

Stock-based compensation related to options granted to non-employees was $0.2 million and $0.1 million for the three months ended March 31, 2020 and 2019, respectively.

The Company allows its employees, non-employees and directors to exercise options granted under the 2014 Plan prior to vesting. The shares related to early exercised stock options are subject to the Company’s lapsing repurchase right upon termination of employment at the original purchase price. In order to vest, the holders are required to provide continued service to the Company. The proceeds are initially recorded in other noncurrent liabilities and are reclassified to common stock and additional paid-in capital as the repurchase right lapses. As of March 31, 2020 and December 31, 2019, there were 292,380 and 349,501 shares, respectively, and $0.3 million and $0.3 million, respectively, recorded in other noncurrent liabilities, related to early exercised shares that were subject to repurchase.