In April 2006, the Company’s Board of Directors (the “Board”) adopted and the stockholders approved the 2006 Stock Option Plan (“2006 Plan”), which provided for the grant of incentive and non-statutory stock options. In February 2013 the Board adopted and the stockholders approved the 2013 Equity Incentive Plan (“2013 Plan”), which became effective on March 21, 2013. At that time, the Company ceased to grant equity awards under the 2006 Plan. Under the 2013 Plan, 643 shares of common stock were originally reserved for issuance. Additionally, all reserved and unissued shares under the 2006 Plan were eligible for issuance under the 2013 Plan. The 2013 Plan authorized the award of incentive and non-statutory stock options, restricted stock awards, stock appreciation rights, restricted stock units (“RSUs”), performance awards and stock bonuses to the Company’s employees, directors, consultants, independent contractors and advisors. On January 1 of each calendar year through 2023, the number of shares of common stock reserved under the 2013 Plan automatically increased by an amount equal to 5% of the total outstanding shares as of the immediately preceding December 31, or such lesser number of shares as determined by the Board. Pursuant to terms of the 2013 Plan, the shares available for issuance increased by 861 shares of common stock on January 1, 2023. The 2013 Plan has expired in accordance with its terms and the Company has ceased granting awards under this plan.

On March 24, 2023, the Board approved the Amended and Restated 2013 Equity Incentive Plan ("Amended and Restated Plan") under which incentive and non-statutory stock options, restricted stock awards, stock appreciation rights, RSUs, performance awards and stock bonuses may be awarded to the Company’s employees, directors, consultants, independent contractors and advisors. Under the Amended and Restated Plan, 425 shares of common stock have been reserved for issuance. Additionally, shares that cease to be subject to equity awards that have been granted under the 2006 Plan and the 2013 Plan are eligible for issuance under the Amended and Restated Plan. On January 1 of each calendar year through 2033, the number of shares of common stock reserved under the Amended and Restated Plan will automatically increase by an amount equal to 5% of the total outstanding shares as of the immediately preceding December 31, or such lesser number of shares as determined by the Board. The Amended and Restated Plan is subject to approval by the Company's stockholders within 12 months of the Board approval date, and no shares can be issued under the plan until such stockholder approval has been received. The Company is seeking stockholder approval of the Amended and Restated Plan at its 2023 annual stockholder meeting to be held on May 18, 2023.

A summary of stock option activity under the 2006 Plan and the 2013 Plan is as follows:


	Options Outstanding
	Number of Shares			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
Balances at December 31, 2022		337		$	19.59		4.45	$	—
Options forfeited and cancelled		(8	)		84.29		—		—
Balances at March 31, 2023		329			18.03		4.31		—
Options exercisable		314			18.70		4.22		—
Options vested		314			18.70		4.22		—
Options vested and expected to vest		329			18.03		4.31		—

A summary of RSU activity under the 2013 Plan is as follows:


	RSUs Outstanding
	Number of Shares			Weighted Average Grant Date Fair Value Per Unit
Granted and unvested at December 31, 2022		1,814		$	2.99
RSUs granted		1,464			1.24
RSUs vested		(14	)		3.34
RSUs cancelled and withheld to cover taxes		(29	)		3.13
Granted and unvested at March 31, 2023		3,235		$	2.19

In February 2013, the Board and stockholders approved the 2013 Employee Stock Purchase Plan (“2013 ESPP”), under which 143 shares of common stock were originally reserved for issuance. The 2013 ESPP became effective on March 22, 2013. The 2013 ESPP generally provides for six-month purchase periods ending in May and November and the purchase price for shares of common stock purchased under the 2013 ESPP is 85% of the lesser of the fair market value of the common stock on (1) the first trading day of the applicable offering period and (2) the last trading day of each purchase period in the applicable offering period. On January 1 of each calendar year following the first offering date, the number of shares reserved under the 2013 ESPP automatically increased by an amount equal to 1% of the total outstanding shares as of immediately preceding December 31, but not to exceed 100 shares. Pursuant to terms of the 2013 ESPP, the shares available for issuance increased by 100 shares on January 1, 2023. The 2013 ESPP has expired in accordance with its terms.

On March 24, 2023, the Board approved the Amended and Restated 2013 Employee Stock Purchase Plan ("Amended and Restated ESPP") which provides for six-month purchase periods ending in May and November of each year with the purchase price for each share of common stock purchased being 85% of the lesser of the fair market value of the common stock on (1) the first trading day of the applicable offering period and (2) the last trading day of each purchase period in the applicable offering period. Under the Amended and Restated ESPP, 432 shares of common stock have been reserved for issuance. The Amended and Restated Plan is subject to approval by the stockholders within 12 months of the Board approval date, and no shares can be issued under the plan until such stockholder approval has been received. The Company is seeking stockholder approval of the Amended and Restated ESPP at our 2023 annual stockholder meeting to be held on May 18, 2023.