7. Stockholders’ Equity

In 2005, we adopted the 2005 Stock Option and Incentive Plan (2005 Plan) that authorizes us to grant options, restricted stock and other equity-based awards. As of March 31, 2019, 330,450 options to purchase shares of common stock were outstanding pursuant to grants in connection with the 2005 Plan. No additional shares are available for issuance under the 2005 Plan.

In August 2014, we adopted our 2014 Equity Incentive Plan, amended in May 2017 (2014 Plan), that authorizes us to grant options, restricted stock, and other equity-based awards, subject to adjustment in accordance with the 2014 Plan. The amount, terms of grants, and exercisability provisions are determined and set by our board of directors. As of March 31, 2019, 5,696,121 options to purchase shares of common stock and 32,400 shares of restricted stock were outstanding pursuant to grants in connection with the 2014 Plan, and 1,880,929 shares of common stock were available for future issuance. The amount, terms of grants, and exercisability provisions are determined and set by our board of directors.

Stock Options

There were 6,492,571 stock options outstanding as of March 31, 2019 at a weighted-average exercise price of $5.13 per share. During the three months ended March 31, 2019, 1,813,000 options were granted to employees and directors at a weighted-average exercise price of $3.91 per share.

Total compensation cost recognized for all stock option awards in the statements of operations is as follows (in thousands):


	Three Months Ended
	March 31,
	2019		2018
Research and development	$	649	$	313
General and administrative		1,177		778
Total	$	1,826	$	1,091

Restricted Stock

All issued and outstanding restricted shares of common stock are time-based, and become vested between one and three years after the grant date. Compensation expense is recorded ratably over the requisite service period. Compensation expense related to restricted stock is measured based on the fair value using the closing market price of our common stock on the date of the grant.

We did not issue any restricted shares of common stock during the three months ended March 31, 2019 or 2018. As of March 31, 2019 there were 32,400 restricted shares of common stock outstanding, and 52,600 shares vested during the three months ended March 31, 2019.

Total compensation cost recognized for all restricted stock awards in the statements of operations is as follows (in thousands):


	Three Months Ended
	March 31,
	2019		2018
Research and development	$	5	$	7
General and administrative		5		28
Total	$	10	$	35