Effective June 1, 2021, the Company adopted a new stock incentive plan (New Incentive Plan) and an employee stock purchase plan (ESPP).

The New Incentive Plan authorizes the Board of Directors to administer the New Incentive Plan to provide equity‑based compensation in the form of stock options, stock appreciation rights., restricted stock, restricted stock units and Dividend Equivalents.

The Corporation currently maintains its existing Share Option Plan and 2015 Stock Incentive Plan (2015 SIP). Effective June 1, 2021 no further grants will be made under the Share Option Plan or 2015 SIP, though existing grants under the Share Option Plan will remain in effect in accordance with their terms.

The aggregate number of our common shares, no par value, that may be issued under all awards under the New Incentive Plan is (i) 6,343,242, plus (ii) any of our common shares subject to any outstanding award under our prior plans that, after June 1, 2021, are not purchased or are forfeited or reacquired by us, or otherwise not delivered to the participant due to termination, cancellation or cash settlement of such award subject to the share counting provisions of the New Incentive Plan.

Under both the Share Option Plan and the New Incentive Plan, the exercise price of each option equals the closing trading price of the Company’s stock on the day prior to the grant if the grant is made during the trading day or the closing trading price on the day of grant if the grant is issued after markets have closed. Vesting is provided for at the discretion of the Board of Directors and the expiration of options is to be no greater than 10 years from the date of grant.

The Company uses the fair value based method of accounting for employee awards granted under both plans. The Company calculates the fair value of each stock option grant using the Black‑Scholes option pricing model at the grant date. The stock‑based compensation cost of the options is recognized as stock‑based compensation expense over the relevant vesting period of the stock options using an estimate of the number of options that will eventually vest.

The ESPP, which will be administered by the Board of Directors, allows eligible employees of the Company with an opportunity to purchase Common Shares through accumulated payroll deductions up to a maximum 15% of eligible compensation. The ESPP will be implemented by consecutive offering periods with a new offering period commencing on the first trading day on or after February 1 and August 1 each year, or on such other date as the Board of Directors will determine, and continuing thereafter until terminated in accordance with the Plan. Unless the Board of Directors provides otherwise, the purchase price will be equal to eighty‑five percent (85%) of the fair market value of a Common Share on the offering date or the exercise date, whichever is lower.

The maximum number of Common Shares which will be made available for sale under the ESPP will be 1,700,000 Common Shares.

The Company has not established a first offering period; there are no options outstanding under the ESPP as of September 30, 2021.

Stock option transactions for the nine months ended September 30, 2021 and September 30, 2020, are summarized as follows:

As of September 30, 2021, there was $7.92 million of total unrecognized compensation cost related to non-vested stock options, which is expected to be recognized over an estimated weighted-average period of 1.59 years.

The following table presents the weighted average assumptions that were used in the Black‑Scholes option pricing model to determine the fair value of stock options granted during the period, and the resultant weighted average fair values:

The Company uses historical data to estimate the expected dividend yield and expected volatility of its common shares in determining the fair value of stock options. The expected life of the options represents the estimated length of time the options are expected to remain outstanding.

The following table presents the vesting terms of options granted in the period:

During the nine months period ended September 30, 2021, the option agreements of one officer were modified as part of a separation and release agreement. Vested options of 1,679,169, with exercise prices ranging from $1.03 to $7.44, were allowed to continue to be exercisable for an additional 12 month period, and also 504,833 options that would have expired unvested, were allowed to continue to vest for a 12 month period. As there was no service requirement, during the nine months ended September 30, 2021, the company recorded $945 thousand and $663 thousand additional compensation related to these modifications for the vested and unvested options, respectively.

During the nine-month period ended September 30, 2021, the Company issued 800,000 performance stock option (PSO) to two officers of the Company. One officer received 400,000 PSOs, of which 200,000 PSOs will vest in tranches connected with financing events, and the remaining 200,000 PSOs will vest in connection with licensing and partnering events. The other officer received 400,000 PSOs, of which 200,000 PSOs will vest in tranches connected to dose escalation trials and the remaining 200,000 PSOs will vest in connection with expansion trials. If such performance triggers are not attained, such PSOs will vest on the fourth anniversary of the grant.

Restricted share units

The Company has a stock incentive plan (SIP) pursuant to which the Board may grant stock-based awards comprised of restricted stock units or dividend equivalents to employees, officers, consultants, independent contractors, advisors and non-employee directors of the Company. Each restricted unit is automatically redeemed for one common share of the Company upon vesting. The following table presents the activity under the SIP plan for the nine months ended September 30, 2021 and 2020 the units outstanding.

On March 10, 2020, the Company granted 645,000 restricted share units (RSUs) with a vesting term of three months. On May 5, 2020, the vesting term on the RSUs was extended from three months to four months. On July 10, 2020, all of these restricted share units were vested and were redeemed for 645,000 common shares.

On June 3, 2019, the Company granted 80,000 restricted share units (RSUs), 40,000 of which have a vesting term of three months and the balance have a vesting term of one year. On May 5, 2020, the vesting term on the balance was extended from one year to one year and one month. On July 2, 2020, the remaining of these restricted share units were vested and were redeemed for 40,000 common shares.

The grant date fair value of the RSUs was determined as the closing value of the common shares of the Company on the Nasdaq Stock Market on the date prior to the date of grant.

The Company recorded share-based payment expense related to stock options and RSUs as follows: