The following table summarizes total stock-based compensation expense recognized for the years ended December 31, 2022, 2021 and 2020 (in thousands).

The related party amounts were for milestone incentives that either were earned or are deemed probable to be achieved in the future and become issuable at that time (as detailed below in Restricted Stock Awards).

During the year ended December 31, 2022, the Company reversed approximately $1.4 million and $0.3 million of stock-based compensation expense in research and development and general and administrative, respectively, which were related to the cancellation of certain unvested performance-based awards.

The Black-Scholes option pricing model is used to estimate the fair value of stock options granted. The weighted average assumptions used in calculating the fair values of stock options that were granted during the years ended December 31, 2022, 2021 and 2020:

The total unrecognized compensation cost was approximately $1.6 million as of December 31, 2022 and will be recognized over the next 1.3 years.

On May 29, 2020, the Board of Directors of the Company approved a new equity compensation plan (the “Plan”). The Company’s prior plan was adopted in 2007, was updated in amended and restated plans that were approved by shareholders in 2012 and 2013 and expired in 2017 (the “Prior Plan”).

The Plan is substantially similar to the Prior Plan. The Plan still has a 10-year life, and allows for awards to employees, directors and consultants of the Company. The Plan allows for any type of equity security to be awarded, as did the Prior Plan. The awards and their terms (including vesting) will be determined by the Board and applicable Committees, as was the case under the Prior Plan. The Plan establishes a pool for equity compensation equal to twenty percent of the outstanding securities of the Company, which is on an evergreen basis as under the Prior Plan.

On February 25, 2022, the Company amended its existing Equity Compensation Plan, which was adopted in 2020 as previously reported. The amendment provides that the possible forms of awards under the Plan include awards paid in cash or awards paid in a combination of cash and equity, in addition to the existing provisions for awards made in any form of equity. The amendment also clarifies that a delegation of authority from the Board to a Committee may be either a general delegation or a delegation for a specific occasion.

The following table summarizes stock option activity under the Company’s option plans (including awards to key external consultants and vendors in addition to internal parties) during the years ended December 31, 2022, 2021 and 2020 (in thousands, except per share number):

(1)

The options granted during the year ended December 31, 2020 included options already approved at various times during the three years 2018 - 2020 but not issued until Q3 2020, and also included options that will vest for performance and milestones going forward over the next two years. The options included awards to key external consultants and vendors in addition to internal parties.

(2)	The weighted average exercise price of the Q3 2020 options was initially $0.25. However subsequently, the exercise price was amended to a weighted average exercise price of $0.36.

(3)	Awards granted to Flaskworks employees and consultants.

(4)	Approximately 83.3 million options were not exercisable until January 12, 2023, and 153.3 million options are not exercisable until at least April 30, 2023.

The existing options and warrants held by Ms. Linda Powers, the Company’s Chief Executive Officer, and Mr. Leslie Goldman, the Company’s Senior Vice President, General Counsel are subject to a voluntary blocking agreement under which they cannot be exercised except upon at least 61 days’ prior notice to the Company.

Stock Options Modification

On April 30, 2020, the Company’s CEO, Linda Powers agreed to not exercise approximately 39.2 million existing options held by her for six months, until November 1, 2020 and correspondingly extended the contractual term for six months. The Company recognized approximately $78,000 of incremental stock-based compensation for this modification during the year ended December 31, 2020, based on the following weighted average assumptions:


	Post Modification			Pre Modification
Exercise price	$	0.23		$	0.23
Expected term (years)		4.3			4.0
Expected stock price volatility		97	%		97	%
Risk-free rate of interest		0	%		0	%

For another former officer, on August 5, 2020, the Company cancelled 1.75 million options which were originally issued in December 2019 and issued 3.0 million options (the “Replacement Options”) with an exercise price of $0.22 and vesting of 1/3 immediately and the remaining 2/3 vesting ratably over the following 24 months from the grant date. The incremental stock-based compensation for this modification was approximately $0.3 million based on the following weighted average assumptions, which will be amortized over the new vesting terms.


	Post Modification			Pre Modification
Exercise price	$	0.22		$	0.22
Expected term (years)		5.3			4.7
Expected stock price volatility		96	%		97	%
Risk-free rate of interest		0	%		0	%

Flaskworks

On August 28, 2020, the Company entered into a Unit Purchase Agreement (the “Agreement”) to acquire Flaskworks. Included in the consideration pursuant to the Agreement was Stock Consideration in the amount of approximately $2.0 million. This Stock Consideration is issued in the form of Rights to receive such value in shares issued pursuant to and subject to the vesting criteria set forth in a Rights Issuance Agreement entered into in connection with the closing of Flaskworks Acquisition. Because the Rights were subject to future employment and performance conditions, the Stock Consideration was not included in consideration payable for the Flaskworks Acquisition but rather was recorded as contingent consideration payable to employees for accounting purposes. The Company anticipates that the treatment of this Stock Consideration for tax purposes may be different than for accounting purposes and will reflect the fact that this Stock Consideration was payment for acquisition of the ownership interests of certain shareholders of Flaskworks.

On December 1, 2020, the Company issued 1.5 million shares of common stock based upon the Flaskworks team having completed a significant milestone, in accordance with the Rights Issuance Agreement entered on August 28, 2020. During the year ended December 31, 2022, the Company reversed approximately $1.2 million stock-based compensation due to cancellation of certain unvested performance-based awards. Approximately $0.3 million was reversed from general and administrative and $0.9 million was reversed from research and development during the year ended December 31, 2022. During the years ended December 31, 2021 and 2020, the Company recognized approximately $0.7 million and $1.0 million stock-based compensation related to the Flaskworks Acquisition, respectively. Approximately $0.1 million was recognized in general and administrative and $0.5 million was recognized in research and development during the year ended December 31, 2021. Approximately $0.5 million was recognized in general and administrative and $0.5 million was recognized in research and development during the year ended December 31, 2020.

Restricted Stock Awards

During April 2022, the Company’s Board approved, and the Company entered into a Statement of Work #6 (the “SOW 6”) with Advent BioServices, a related party of the Company, for five workstreams that are prerequisites for an application for regulatory approval of DCVax-L, for three required licenses for the Sawston facility, and for drafting of key portions of the application. The SOW provides for baseline costs and for milestone incentives for successful completion of each of the workstreams, for the completion and submission of each application for product approval, and for obtaining regulatory approval of each of the three Sawston licenses. The milestone incentives will be a combination of cash and stock and are not paid until they are achieved. On September 26, 2022, the Company amended the SOW6 (the “Amended SOW6”) to (1) extend the service period through September 30, 2023, and (2) clarify the assessment and application of the milestones, and (3) add a sixth workstream. (The potential cost for all unearned stock awards for milestones not yet achieved was re-measured on the modification date and will be further re-measured until the date the milestone award is achieved and the stock awards are earned.) If all of the 10 one-time milestones are achieved (i.e., for all six workstreams that are prerequisites for an application for product approval, for obtaining all three licenses required for the Sawston facility, and for the completion of key portions of the application for product approval), the aggregate stock-based compensation under the Amended SOW 6 will be 13.5 million shares (including the shares already earned and issued for the milestones already achieved). As of December 31, 2022, the 13.5 million shares had an aggregate fair value of $10.1 million.

During the year ended December 31, 2022, the Company recognized and expensed (but only partly paid) approximately $4.0 million related to the cash component of seven one-time milestones that were completed and earned during the period. The seven completed milestones included five of the workstreams, and the regulatory approvals of two licenses required for the Sawston facility. (An eighth milestone was partly completed and the stock component of that milestone was earned, as described below, but the cash portion of that eighth milestone was not yet earned).

For the cash components of three further one-time milestones under Amended SOW6 that are anticipated to be achieved and earned in the future, the Company recognized and expensed (but did not pay) during the year ended December 31, 2022, the pro-rata portion of $3.7 million.

For the stock component of the eight one-time milestones that were earned during the year ended December 31, 2022 (as also described above, in Stock Based Compensation), the Company recognized and expensed $5.9 million for the 7.5 million shares.

For two further one-time milestones that are anticipated to be achieved and earned in the future, the Company recognized and expensed (but did not issue) the pro-rata portion of the remaining potential milestone stock awards during the year ended December 31, 2022, of $3.5 million (as also described above, in Stock Based Compensation).

Other Service Agreement

On August 22, 2022, the Company issued 1.6 million shares of common stock to certain unrelated vendors who provided professional services for the Company. The fair value of the common shares on the issuance date was approximately $1.0 million and was recognized as part of general and administrative expenses.