2017 Equity Incentive Plan: In September 1995, Lexicon adopted the 1995 Stock Option Plan, which was subsequently amended and renamed the 2017 Equity Incentive Plan (the “Equity Incentive Plan”).

The Equity Incentive Plan permits the grant of incentive stock options to employees and nonstatutory stock options to employees, directors and consultants of the Company. The plan also permits the grant of stock bonus awards, restricted stock awards, restricted stock unit awards, stock appreciation rights and performance stock awards. Incentive and nonstatutory stock options have an exercise price of 100% or more of the fair market value of the Company’s common stock on the date of grant. Most stock options granted under the Equity Incentive Plan become vested and exercisable over a period of four years; however some have been granted with different vesting schedules. Stock options granted under the Equity Incentive Plan have a term of ten years from the date of grant.

The total number of shares of common stock that may be issued pursuant to stock awards under the Equity Incentive Plan shall not exceed in the aggregate 30,000,000 shares at December 31, 2022. As of December 31, 2022, options to purchase 11,847,723 shares and 2,559,306 restricted stock units were outstanding, 2,285,702 shares had been issued upon the exercise of stock options, 5,294,942 shares had been issued pursuant to restricted stock units and 113,940 shares had been issued pursuant to stock bonus awards or restricted stock awards granted under the Equity Incentive Plan.

2017 Non-Employee Directors’ Equity Incentive Plan: In February 2000, Lexicon adopted the 2000 Non-Employee Directors’ Stock Option Plan, which was subsequently amended and renamed the 2017 Non-Employee Directors’ Equity Incentive Plan (the “Directors’ Plan”). Under the Directors’ Plan, non-employee directors may be granted awards under the plan with an aggregate grant date fair value of no more than $500,000 during any calendar year, taken together with any cash fees paid to such non-employee director in compensation for service on Lexicon’s board of directors during such calendar year. Stock options granted under the Directors’ Plan have an exercise price equal to the fair market value of the Company’s common stock on the date of grant and a term of ten years from the date of grant.

The total number of shares of common stock that may be issued pursuant to stock awards under the Directors’ Plan shall not exceed in the aggregate 1,200,000 shares at December 31, 2022. As of December 31, 2022, stock options to purchase 501,224 shares were outstanding, none had been issued upon the exercise of stock options, 74,416 restricted stock units were outstanding and 248,232 shares had been issued pursuant to restricted stock and restricted stock unit awards granted under the Directors’ Plan.

The following is a summary of stock option activity under Lexicon’s equity incentive plans:


	2022			2021			2020
(in thousands, except exercise price data)	Options	Weighted Average Exercise Price		Options	Weighted Average Exercise Price		Options	Weighted Average Exercise Price
Outstanding at beginning of year	8,367	$	6.80	8,397	$	7.12	7,695	$	8.95
Granted	5,099	2.97		1,808	6.39		3,495	3.24
Exercised	—	—		(376)	4.37		—	—
Expired	(163)	12.50		(191)	12.50		(236)	12.91
Forfeited	(954)	7.41		(1,271)	8.17		(2,557)	6.78
Outstanding at end of year	12,349	5.10		8,367	6.80		8,397	7.12
Exercisable at end of year	5,747	$	7.00	5,032	$	7.99	4,684	$	9.48

The weighted average estimated grant date fair value of stock options granted during the years ended December 31, 2022, 2021 and 2020 were $2.30, $4.85 and $2.35, respectively. The total intrinsic value of stock options exercised during the year ended December 31, 2022 was $0. The weighted average remaining contractual term of stock options outstanding and exercisable was 7.2 and 5.3 years, respectively, as of December 31, 2022. At December 31, 2022, the aggregate intrinsic value of the outstanding stock options was $0.1 million. At December 31, 2022, the intrinsic value of exercisable stock options was $0.

During the years ended December 31, 2022, 2021 and 2020, Lexicon granted its employees restricted stock units in lieu of or in addition to annual stock option awards. These restricted stock units vest in three annual installments. The total fair value of shares vested in 2022, 2021 and 2020 was $2.9 million, $8.7 million and $3.2 million, respectively.

During the years ended December 31, 2022, 2021 and 2020, Lexicon granted its non-employee directors 74,416, 32,192 and 85,104 restricted stock units, respectively. The restricted stock granted in 2022, 2021 and 2020 had weighted average grant date fair values of $1.77, $5.04 and $1.86 per share, respectively. Vesting of restricted stock units occurs on the first anniversary of the grant date.


	Shares	Weighted Average Grant Date Fair Value
	(in thousands)
Outstanding at December 31, 2021	1,854	$	5.16
Granted	2,185	3.15
Vested	(1,012)	4.86
Forfeited	(279)	4.03
Outstanding at December 31, 2022	2,748	$	3.78

During the year ended December 31, 2022, the Company issued $6.3 million of Treasury shares in lieu of issuing additional authorized common shares in order to satisfy the annual vesting of restricted stock units for its employees and officers.

As of December 31, 2022, an aggregate of 15,096,609 shares of common stock were reserved for issuance upon exercise of outstanding stock options and vesting of outstanding restricted stock units and 8,160,575 additional shares were available for future grants under Lexicon’s equity incentive plans. The Company has a policy of using either authorized and unissued shares or treasury shares, including shares acquired by purchase in the open market or in private transactions, to satisfy equity award exercises.