NewAmsterdam Pharma Co N.V.

Item 5. Other Information.

Rule 10b5-1 Trading Arrangements

Except as set forth below, during the three months ended September 30, 2025, none of our officers or directors adopted, amended or terminated a “Rule 10b5-1 trading arrangement,” as defined in Item 408(c) of Regulation S-K, each of which is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act.

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On September 23, 2025, Louise Kooij, our Chief Accounting Officer, adopted a Rule 10b5-1 trading arrangement for the potential sale of up to 290,000 Ordinary Shares, subject to certain price thresholds and other conditions. Thearrangement'sexpiration date is June 30, 2026.

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On September 26, 2025, Michael Davidson, our Chief Executive Officer, terminated a Rule 10b5-1 trading arrangement that he initially adopted on March 10, 2025, and modified on June 30, 2025, and replaced it with a new Rule 10b5-1 trading arrangement adopted on September 29, 2025 providing for the potential sale of up to 750,000 Ordinary Shares, subject to certain price thresholds and other conditions. Thearrangement'sexpiration date is March 5, 2026.

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On September 29, 2025, Douglas Kling, our Chief Operating Officer, adopted a Rule 10b5-1 trading arrangement for the potential sale of up to 594,573 Ordinary Shares, subject to certain price thresholds and other conditions. Thearrangement'sexpiration date is December 31, 2026.

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On September 30, 2025, Ian Somaiya, our Chief Financial Officer, adopted a Rule 10b5-1 trading arrangement for the potential sale of up to 200,000 Ordinary Shares, subject to certain price thresholds and other conditions. Thearrangement'sexpiration date is February 20, 2026.

Except as set forth below, no officer or director adopted, amended orterminated a “non-Rule 10b5-1 trading arrangement,” as defined in Item 408(c) of Regulation S-K, during the three months ended September 30, 2025.

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In September 2025, each holder of outstanding restricted stock units (including each of our officers) entered into a Sell-to-Cover Agreement that constitute a "non-Rule 10b5-1 trading arrangement," which provides for the pre-arranged sale of a portion of any Ordinary Shares deliverable to such holder in connection with the vesting and/or settlement of such holder's restricted stock units in order to satisfy any taxes required to be withheld in connection with such vesting and/or settlement event. The amount of Ordinary Shares to be sold to satisfy such tax withholding obligations under the Sell-to-Cover Agreements is dependent on the then-prevailing market price of the Ordinary Shares at the time of the vesting of the restricted stock units. Each Sell-to-Cover Agreement remains in effect until the date on which the holder’s tax withholding obligations arising from the last vesting or settlement event of the applicable restricted stock units have been satisfied, unless earlier terminated in certain limited circumstances.

Director Resignation

On November 2, 2025, Nicholas Downing notified our Board of Directors of his decision to resign from the Company’s Board of Directors and its committees, effective as of November 5, 2025. Mr. Downing’s resignation was not the result of any disagreement with us on any matter relating to our operations, policies, or practices. We and our Board of Directors wish to express our appreciation for Mr. Downing’s service and contributions during his tenure on the Board.