NKGen Biotech (NKGN) boosts AlpineBrook note and extends equity forward date

Rhea-AI Filing Summary

NKGen Biotech, Inc. filed an 8-K describing two financing-related amendments. On January 20, 2026, the company and Meteora-affiliated counterparties signed an eighth amendment to their forward purchase agreement for OTC equity prepaid forward transactions, extending the agreement’s Valuation Date to December 31, 2026 while keeping all other terms the same.

On January 23, 2026, NKGen Biotech, Inc. and NKGen Operating Biotech, Inc. entered into a second amendment to their secured promissory note with AlpineBrook Capital GP I Limited, providing an additional $372,000 loan. This increased the note’s principal amount to $26,507,106 and confirmed that interest on this third additional loan accrues from January 23, 2026.

false 0001845459 0001845459 2026-01-20 2026-01-20 0001845459 NKGN:CommonStock0.0001ParValuePerShareMember 2026-01-20 2026-01-20 0001845459 NKGN:WarrantsEachWholeWarrantExercisableForOneShareOfCommonStockAtExercisePriceOf11.50PerShareMember 2026-01-20 2026-01-20 iso4217:USD xbrli:shares iso4217:USD xbrli:shares

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15 (d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 20, 2026

NKGen Biotech, Inc.

(Exact name of registrant as specified in its charter)

Delaware		001-40427		86-2191918
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

3001 Daimler Street

Santa Ana, CA, 92705

(Address of principal executive offices and zip code)

Registrant’s telephone number, including area code: (949) 396-6830

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2 below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, $0.0001 par value per share		NKGN		OTC Expert Market
Warrants, each whole warrant exercisable for one share of Common Stock at an exercise price of $11.50 per share		NKGNW		OTC Expert Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01. Entry into a Material Definitive Agreement.

On January 20, 2026, NKGen Biotech, Inc. (the “Company” and formerly known as Graf Acquisition Corp. IV) and Seller (defined below) entered into an eighth amendment (the “FPA Amendment”) to the forward purchase agreement, dated as of September 22, 2023 (the “FPA”), initially among the Company, Graf, Meteora Strategic Capital, LLC (“MSC”), Meteora Capital Partners, LP (“MCP”) and Meteora Select Trading Opportunities Master, LP (“MSTO” with MSC, MCP, and MSTO collectively, “Seller”) for OTC Equity Prepaid Forward Transactions, as amended on December 26, 2023, as further amended on January 2, 2024, January 11, 2024, February 21, 2024, July 12, 2024, September 5, 2024, and December 31, 2024.

Pursuant to the FPA Amendment, the Company and Seller agreed to extend the Valuation Date (as defined in the FPA) to December 31, 2026, or as otherwise described in the FPA Amendment. All other terms and conditions remained unchanged.

On January 23, 2026, the Company and NKGen Operating Biotech, Inc., a Delaware corporation (together with the Company, the “Borrowers”), entered into a second amendment (the “Alpine Second Amendment”) to that certain secured promissory note with AlpineBrook Capital GP I Limited, dated January 5, 2026, as amended by that certain amendment to secured promissory note dated January 12, 2026 (the “Note”).

The Alpine Second Amendment provides an additional $372,000 of funding to the Borrowers (the “Third Additional New Loan”). As a result, the principal amount of the Note was increased to $26,507,106. The Alpine Second Amendment also clarifies that interest on the Third Additional New Loan accrues from January 23, 2026 (the date on which the Alpine Second Amendment was entered into).

The foregoing description of the FPA Amendment and Alpine Second Amendment do not purport to be complete and are qualified in their entirety by the terms and conditions of the FPA Amendment and Alpine Second Amendment, which are filed as Exhibits 10.1 and 10.2, respectively, to this Current Report on Form 8-K and incorporated herein by reference.

Item 2.03. Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The disclosures set forth in Item 1.01 are incorporated by into this Item 2.03 by reference.

Item 9.01. Financial Statements and Exhibits

(d) Exhibits.

Exhibit No.		Description
10.1		Eighth Amendment to Forward Purchase Agreement, dated as of January 20, 2026, among NKGen and Meteora Capital Partners, LP and certain of its affiliates.
10.2		Amendment No. 2 to Secured Promissory Note issued to the AlpineBrook Capital GP I Limited, dated January 23, 2026.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

1

SIGNATURES

Pursuant to the requirements of Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	NKGEN BIOTECH, INC.
Date: January 26, 2026	/s/ Paul Y. Song
	Name:	Paul Y. Song
	Title:	Chief Executive Officer
		(Principal Executive Officer)

2

FAQ

What did NKGen Biotech (NKGN) change in its forward purchase agreement?

NKGen Biotech entered into an eighth amendment to its forward purchase agreement for OTC equity prepaid forward transactions on January 20, 2026. The amendment extends the Valuation Date to December 31, 2026, with all other terms and conditions remaining unchanged.

How much additional funding did NKGen Biotech receive under the AlpineBrook promissory note?

Under the second amendment to the secured promissory note with AlpineBrook Capital GP I Limited, the borrowers received an additional $372,000. This new funding is described as the Third Additional New Loan.

What is the new total principal amount of NKGen Biotech’s AlpineBrook note?

After the additional $372,000 of funding, the principal amount of the secured promissory note with AlpineBrook was increased to $26,507,106.

From what date does interest accrue on NKGen Biotech’s Third Additional New Loan?

The amendment clarifies that interest on the Third Additional New Loan under the AlpineBrook note accrues from January 23, 2026, the date of the second amendment.

Which counterparties are involved in NKGen Biotech’s forward purchase agreement?

The forward purchase agreement involves NKGen Biotech, Inc., Graf Acquisition Corp. IV, and Meteora entities including Meteora Strategic Capital, LLC, Meteora Capital Partners, LP, and Meteora Select Trading Opportunities Master, LP, collectively referred to as the Seller.

What SEC item does NKGen Biotech reference for the new financial obligation?

The company states that the disclosures about the AlpineBrook secured promissory note amendment in Item 1.01 are incorporated by reference into Item 2.03, which covers creation of a direct financial obligation or an obligation under an off-balance sheet arrangement.