Material Agreement (Form 8-K)

Item 1.01. Entry into a Material Definitive Agreement.

Background

On April 5, 2024, NKGen Biotech, Inc. (the "Company"), NKGen Operating Biotech, Inc. (the "Borrower") and BDW Investments, LLC (the "Lender") entered into an equity and business loan agreement (the "Original Loan Agreement"), which provided for a multi draw term loan financing in a principal amount of up to $5 million. The Original Loan Agreement is described in the Company's Current Report on Form 8-K filed with the Securities and Exchange Commission on April 11, 2024.

First Amendment to Equity and Business Loan Agreement

On July 13, 2026, the Company, the Borrower and the Lender entered into a First Amendment to Equity and Business Loan Agreement (the "Amendment"), which amends certain terms of the Original Loan Agreement. The key terms of the Amendment are as follows:

Security Interest Modifications. The Amendment removes references to the all-assets security agreement entered into in connection with the Original Loan Agreement (which was terminated) and instead provides that the Lender shall have a first priority perfected security interest in certain real estate collateral (the "Real Estate Collateral") of the Borrower, as more fully described in the Amendment. The Real Estate Collateral is secured by that certain BDW Deed of Trust, dated April 5, 2024, as amended by that certain Amended and Restated Deed of Trust, dated April 30, 2026, concerning such real property.

Permitted Liens. The Amendment amends the definition of "Permitted Liens" under the Original Loan Agreement to provide that liens securing certain senior indebtedness may not be granted with respect to any Real Estate Collateral (other than certain customary permitted liens).

Senior Loan Definition. The Amendment amends the definition of "Senior Loan" under the Original Loan Agreement to mean that certain Senior Convertible Loan Agreement, dated as of April 15, 2026, by and between the Loan Parties and AlpineBrook Capital GP I Limited, as the same may be amended, restated, amended and restated, extended, supplemented or otherwise modified from time to time.

Release of Claims. In connection with the Amendment, the Company and the Borrower released the Lender and its related parties from any and all claims arising at any time on or prior to the date of the Amendment relating to the Original Loan Agreement or any related documents or transactions thereunder.

The foregoing description of the Amendment does not purport to be complete and is qualified in its entirety by the terms and conditions of the Amendment, which is filed as Exhibit 10.1 to this Current Report on Form 8-K and incorporated herein by reference. The Original Loan Agreement was filed as Exhibit 10.1 to the Company's Current Report on Form 8-K filed with the Securities and Exchange Commission on April 11, 2024.