NewAmsterdam Pharma Co N.V. Stock Compensation Disclosure

Note 10. Share-Based Compensation

The Company has four Share-based payment plans and one restricted share award in place as at December 31, 2025:

Long Term Incentive Plans

The Plans are equity-settled, and the Company may grant various forms of equity awards, including the granting of options to purchase Ordinary Shares (“Company Options”) and restricted share units (“RSUs”), pursuant to the Plans. In total, as of December 31, 2025 a maximum of 28,435,355 Ordinary Shares may be reserved for issuance pursuant to the Plans. The number of Ordinary Shares reserved for grant under the Plan will increase annually on January 1 of each calendar year by 5% of the then issued and outstanding Ordinary Shares or such lower number as may be determined by the Board of Directors.

The contractual term is 10 years from grant date for options granted under the Plans. In general, each Company Option granted in 2025 has a four-year vesting period with 25% vesting after one year and the remaining 75% vesting in equal monthly installments over the next following three years.

In general, each RSU, other than the Earnout RSUs, has a three-year vesting period with one-third vesting on each one-year anniversary of the vesting start date.

Modification of Options

In 2024, a total of 399,153 Company Options granted to one employee were modified. For 210,655 of the modified Company Options the vesting period was shortened, of which 200,655 such modified Company Options also had the exercise period extended. For the other 188,498 modified Company Options only the exercise period was extended. The total fair value of the 210,655 modified Company Options for which the vesting period was shortened is equal to $1.2 million. Any expense previously recognized for such Company Options was reversed on the modification date and the full fair value of the modified Company Options was recognized over the new applicable service

period. For the 188,498 modified Company Options for which only the exercise period was extended the total fair value of the modification is equal to $0.1 million, all of which is recognized on the modification date.

In 2023, the vesting period was shortened for 490,067 Company Options granted to an employee in relation with the signing of an employment separation agreement. At the modification date, 255,243 Company Options were expected to vest both under the original and the modified vesting conditions. For these Company Options, the modification did not result in any incremental compensation cost. For the 234,824 Company Options that were not probable to vest as of the modification date based on the original terms, the incremental fair value granted is equal to the fair value of the modified award of $12.19 (i.e., the value of the modified award, as determined on the modification date, compared to its prior zero value). In 2023, the total incremental fair value of $2.9 million has been fully recognized over the remaining modified requisite service period.

The weighted average grant date fair value of options, estimated as of the grant date using the Black-Scholes option pricing model, was $12.66, $6.70 and $4.70 per option for options granted during the years ended December 31, 2025, 2024 and 2023, respectively. The total intrinsic value (the amount by which the fair market value exceeded the exercise price) of stock options exercised during the years ended December 31, 2025, 2024 and 2023 was $59.9 million, $27.2 million and $1.7 million, respectively. Weighted average assumptions used to apply this pricing model were as follows:

Expected Term

The Company’s expected term represents the period that the Company’s stock-based awards are expected to be outstanding and is determined using the simplified method (based on the mid-point between the vesting date and the end of the contractual term). The Company utilizes this method due to lack of historical exercise data and the plain-vanilla nature of the Company’s stock-based awards.

Expected Volatility

Since the Company was privately held through November 2022, it alone does not have sufficient relevant company-specific historical data to support its expected volatility alone. Prior to 2024, due to the insufficiency of historical volatility data on the Company’s own securities, the expected volatility input was determined using comparable companies alone. Beginning on January 1, 2024 expected volatility input was determined using a weighted average

calculation considering the volatility of the Company’s own securities and the volatilities of a representative group of publicly traded biopharmaceutical companies over a period equal to the expected term of the stock option grants. Initially, the volatility of the Company’s Ordinary Shares is assigned a weighting of 10%. This weighting will be increased by 5% per calendar quarter (i.e. 45% in Q4 2025), until the expected volatility input is based entirely on the historical volatility of the Company’s Ordinary Shares. For purposes of identifying comparable companies, the Company selected companies with comparable characteristics, including enterprise value, risk profiles, position within the industry, and with historical share price information sufficient to meet the expected life of the stock-based awards. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards.

Risk-Free Interest Rate

The risk-free interest rate is based upon the U.S. Treasury yield curve in effect at the time of grant, with a term that approximates the expected life of the option.

Expected Dividend Yield

The expected dividend yield is zero as the Company currently has no history or expectation of declaring dividends on its ordinary shares.

Restricted Share Units (“RSUs”)

As at December 31, 2024, the Company had allocated 143,002 Earnout Shares to be granted to Participating Optionholders if and when a certain clinical development milestone is achieved during the earnout period. In March 2025, it was determined that the earnout milestone triggering event set forth in the Business Combination Agreement had occurred and, as a result, Earnout Shares were delivered in the form of awards of RSUs (the “Earnout RSUs”) granted pursuant to the LTIP Plan to such Participating Optionholders who were, at the time of achievement of such milestone, still providing services to the Company. In total, 143,001 Earnout RSUs were granted, all of which have vested. Though the Earnout RSUs were only legally granted upon the achievement of the milestone triggering event, in accordance with ASC 718, the Company determined the grant date of such Earnout RSUs to be November 22, 2022 for accounting purposes and began recognizing the associated share-based compensation expenses once the milestone was deemed probable to occur.

As of December 31, 2025, there was $37.3 million and $7.8 million of unrecognized compensation cost related to Company Options and RSUs that have not yet vested, respectively. These costs are expected to be recognized over a weighted average remaining vesting period of 2.8 years and 2.1 years for the Company Options and the RSUs, respectively.