On December 31, 2020, the Company filed an amendment to its Certificate of Incorporation which effected a 1-for-6 reverse stock split of the shares of the Company’s outstanding common stock and proportionate reduction in the number of authorized shares of its common stock from 370,000,000 to 61,666,666 and from 80,000,000 to 13,333,333 as of December 31, 2020 and 2019, respectively. As such, all figures in this report relating to shares of the Company’s common stock (such as share amounts, per share amounts, and conversion rates and prices), including in the financial statements and accompanying notes to the financial statements, have been retroactively restated to reflect the 1-for-6 reverse stock split of the common stock.

On January 12, 2006, the Company’s board of directors approved the adoption of the Acorda Therapeutics, Inc. 2006 Employee Incentive Plan (the 2006 Plan). The 2006 Plan served as the successor to the Company’s 1999 Plan, as amended, and no further option grants or stock issuances were to be made under the 1999 Plan after the effective date, as determined under Section 14 of the 2006 Plan. All employees of the Company were eligible to participate in the 2006 Plan, including executive officers, as well as directors, independent contractors, and agents of the Company. The 2006 Plan also covered the issuance of restricted stock.

The 2006 Plan was administered by the Compensation Committee of the Board of Directors, which selected the individuals to be granted options and restricted stock, determined the time or times at which options and restricted stock were to be granted, determined the number of shares to be granted subject to any option or restricted stock and the duration of each option and restricted stock, and made any other determinations necessary, advisable, and/or appropriate to administer the 2006 Plan. Under the 2006 Plan, each option granted expires no later than the tenth anniversary of the date of its grant. The number of shares of common stock authorized for issuance under the 2006 Plan as of December 31, 2021 was 2,485,342 shares. As of December 31, 2021, the Company had granted an aggregate of 1,955,881 shares as restricted stock or subject to issuance upon exercise of stock options under the 2006 Plan, of which 313,569 shares remained subject to outstanding options.

On June 9, 2015, the Company’s stockholders approved the adoption of the Acorda Therapeutics, Inc. 2015 Omnibus Incentive Compensation Plan (the 2015 Plan). The 2015 Plan serves as the successor to the Company’s 2006 Plan, as amended, and no further option or stock grants were made under the 2006 Plan after the effective date of the 2015 Plan. All employees of the Company are eligible to participate in the 2015 Plan, including executive officers, as well as directors, consultants, advisors and other service providers of the Company or any of its subsidiaries. The 2015 Plan also covers the issuance of restricted stock.

The 2015 Plan is administered by the Compensation Committee of the Board of Directors, which selects the individuals to be granted options, restricted stock, and restricted stock units, determines the time or times at which options, restricted stock, and restricted stock units are to be granted, determines the number of shares to be granted subject to any option, restricted stock or restricted stock unit and the duration of each option, restricted stock, and restricted stock unit, and makes any other determinations necessary, advisable, and/or appropriate to administer the 2015 Plan. Under the 2015 Plan, each option granted expires no later than the tenth anniversary of the date of its grant. Since inception, the number of shares of common stock authorized for issuance under the 2015 Plan as of December 31, 2021 is 1,350,000 shares, plus shares underlying cancelled awards under the 2006 plan after the adoption of the 2015 plan. As of December 31, 2021, the Company had granted an aggregate of 1,408,784 shares either as restricted stock or shares subject to issuance upon the exercise of stock options under the 2015 Plan, of which 701,976 shares remained subject to outstanding options.

On April 14, 2016 the Compensation Committee of the Company’s Board of Directors (the “Compensation Committee”) approved the Acorda Therapeutics, Inc. 2016 Inducement Plan (the “2016 Plan”) to provide equity compensation to certain individuals of the Company (or its subsidiaries) in order to induce such individuals to enter into employment with the Company or its subsidiaries. Equity awards were issued under this plan to individuals employed by Biotie Therapies Ltd., formerly Biotie Therapies Corp., and its subsidiary Biotie Therapies, Inc. (collectively, “Biotie”) in connection with our 2016 acquisition of Biotie, however the last of these awards terminated in 2020. In 2021, 170,000 stock option awards were issued under this plan to newly-hired executive officers as an inducement for them to become employed by the Company, and as of December 31, 2021, such awards remained outstanding and were the only awards that were outstanding under the 2016 Plan.

On June 19, 2019, the Company’s stockholders approved the Company’s 2019 Employee Stock Purchase Plan (the “2019 ESPP”) at the annual meeting of stockholders pursuant to which up to 250,000 shares of the Company’s common stock, par value $0.001 per share may be issued thereunder (the “Plan Shares). As of December 31, 2021, there were 250,000 shares of common stock remaining authorized for issuance under the 2019 ESPP.

The fair value of each option granted is estimated on the date of grant using the Black‑Scholes option‑pricing model with the following weighted average assumptions:

	Year ended December 31,
	2021			2020
Employees and directors:
Estimated volatility%		84.26	%		80.28	%
Expected life in years		6.25			6.31
Risk free interest rate%		1.36	%		0.69	%
Dividend yield		—			—

The Company estimated volatility for purposes of computing compensation expense on its employee and director options using the historic volatility of the Company’s stock price. The expected life used to estimate the fair value of employee and director options is based on the historical life of the Company’s options based on exercise data.

The weighted average fair value per share of options granted to employees and directors for the years ended December 31, 2021 and 2020 amounted to approximately $2.57 and $3.95, respectively. No options were granted to non-employees for the years ended December 31, 2021 and 2020.

During the year ended December 31, 2021, the Company granted 596,795 stock options to employees and directors under all plans. The stock options were issued with a weighted average exercise price of $3.72 per share. As a result of these grants, the total compensation charge to be recognized over the estimated service period is $2.0 million, of which $0.9 million was recognized during the year ended December 31, 2021.

Compensation costs for options and restricted stock granted to employees and directors amounted to $3.0 million and $8.1 million, for the years ended December 31, 2021 and 2020, respectively. Of the total compensation cost, there was $0 and $0.3 million compensation cost capitalized in inventory balances for the years ended December 31, 2021 and December 31, 2020, repectively. Compensation expense for options and restricted stock granted to employees and directors are classified in inventory, research and development, selling, general and administrative, and cost of sales expense based on employee job function. The following table summarizes share-based compensation expense included within the Company’s consolidated statements of operations:

	Year ended December 31,
(In thousands)	2021		2020
Research and development	$	694	$	1,745
Selling, general and administrative		2,282		6,020
Cost of sales		19		335
Total	$	2,995	$	8,100

A summary of share‑based compensation activity for the year ended December 31, 2021 is presented below:

	Number of Shares (In thousands)			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Intrinsic Value (In thousands)
Balance at December 31, 2020		1,331		$	127.13
Granted		336			3.72
Forfeited and expired		(481	)		121.78
Exercised		—			—
Balance at December 31, 2021		1,186		$	94.38		5.5	$
Vested and expected to vest at December 31, 2021		1,172		$	95.42		5.5	$
Vested and exercisable at December 31, 2021		872		$	125.89		4.0		—

	Options Outstanding						Options Exercisable
Range of exercise price	Outstanding as of December 31, 2021 (In thousands)		Weighted- average remaining contractual life (In years)		Weighted- average exercise price		Exercisable as of December 31, 2021 (In thousands)		Weighted- average exercise price
$3.16 - $3.74		276		9.8	$	3.70		1	$	3.18
$3.75 - $14.46		284		7.1		11.98		257	$	12.77
$15.30 - $164.85		265		3.6		124.60		253	$	126.67
$165.30 - $214.44		277		2.5		197.68		277	$	197.70
$215.28 - $246.42		84		2.1		234.91		84	$	234.91
		1,186		5.5	$	94.38		872	$	125.89

Unrecognized compensation cost for unvested stock options and restricted stock awards as of December 31, 2021 totaled $1.6 million and is expected to be recognized over a weighted average period of approximately 3.3 years.