The Company’s 2014 Stock Option and Incentive Plan, as amended (the “2014 Plan”) provides for the grant of stock options, stock appreciation rights, restricted stock awards, restricted stock units, unrestricted stock awards, performance-share awards, cash-based awards and dividend equivalent rights to employees, members of the board of directors and consultants of the Company. The Company has outstanding stock-based awards under its Amended and Restated 2006 Stock Option Plan but is no longer granting awards under this plan. The Company also issues common stock under its 2014 Employee Stock Purchase Plan (the “ESPP”). As of March 31, 2020, 6,795,572 shares are available for grant under the 2014 Plan, including 1,497,859 shares automatically added to the 2014 Plan on January 1, 2020, and 58,611 shares are available for issuance to participating employees under the ESPP.

The Company recorded stock-based compensation expense related to stock options, restricted common stock and the ESPP in the following expense categories within its condensed consolidated statements of operations for the three months ended March 31, 2020 and 2019 as follows:

	Three Months Ended March 31,
	2020			2019
	(in thousands)
Research and development	$	(144	)	$	960
General and administrative		854			1,116
	$	710		$	2,076

The Company recorded negative research and development expenses during the three months ended March 31, 2020, which was the result of the reversal of related stock compensation expense related to the termination of the Company’s final research and development employee in the first quarter of 2020.