Troculeucel

Dr. Miller’s appointment further enhances NKGen’s scientific and clinical advisory capabilities as the Company advances its research in Alzheimer’s and other related neurodegenerative diseases. SANTA ANA, Calif., January 22, 2026 – NKGen Biotech, Inc. (OTC: NKGN) (“NKGen” or the “Company”), a clinical-stage biotechnology company focused on the development and commercialization of innovative autologous and allogeneic natural killer (“NK”) cell therapeutics, today announced the appointment of Bruce L. Miller, M.D. to its Scientific Advisory Board. Dr. Miller is internationally recognized for his leadership in Alzheimer’s disease (“AD”), frontotemporal dementia (“FTD”), and other neurocognitive disorders, and brings extensive scientific and clinical expertise to the Company. Dr. Miller is the A.W. and Mary Margaret Clausen Distinguished Professor in Neurology at the University of California, San Francisco (“UCSF”) where he directs the Edward and Pearl Fein Memory and Aging Center and is the founding director of the Global Brain Health Institute. His career spans decades at the forefront of clinical care, research, and education in neurodegenerative disease, advancing understanding of the brain-behavior relationship, the genetic and molecular foundations of dementia, and precision-medicine approaches for tauopathies and FTD-related conditions. “We are honored to welcome Dr. Miller to our Scientific Advisory Board. His global leadership in neurodegeneration research and his long-standing contributions to the Alzheimer’s and FTD fields bring a level of expertise that will meaningfully inform our clinical and scientific priorities as we continue to execute our development strategy, including our ongoing Phase 2 clinical trial evaluating our autologous NK cell therapy candidate, troculeucel, in individuals with moderate Alzheimer’s disease. We also look to leverage his expertise to further explore the use of troculeucel in FTD, where we have seen some very promising early signals in patients treated under expanded access,” said Paul Y. Song, M.D., Chairman and CEO of NKGen Biotech. “ Dr. Miller has published more than 2,000 peer-reviewed articles, authored seminal books including The Behavioral Neurology of Dementia and Frontotemporal Dementia, and contributed to defining the clinical and biological boundaries between Alzheimer’s disease, FTD, and other neurodegenerative disorders. He has also played a central role in major research collaborations, including work with the Tau Consortium and the Bluefield Foundation, which support the development of potential therapies for tauopathies and progranulin-mediated FTD. About NKGen Biotech NKGen is a clinical-stage biotechnology company focused on the development and commercialization of innovative autologous and allogeneic NK cell therapeutics. NKGen is headquartered in Santa Ana, California, USA. For more information, please visit www.nkgenbiotech.com. Forward-Looking Statements Statements contained in this press release may contain “forward-looking statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. Forward-looking statements may be identified by the use of words such as “anticipate”, “believe”, “could”, “continue”, “expect”, “estimate”, “may”, “plan”, “outlook”, “future” and “project” and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. Because such statements are subject to risks and uncertainties, many of which are outside of the Company’s control, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding the Company’s anticipated timing and content of its filings with the U.S. Securities and Exchange Commission (the “SEC”) and other public disclosures; the Company’s plans and expected timing for developing troculeucel and SNK02, including the expected timing of completing and announcing further results from its ongoing clinical studies; and the Company’s expected timing for developing its product candidates and potential benefits of its product candidates. Risks that contribute to the uncertain nature of the forward-looking statements include: the Company’s ability to execute its plans and strategies; risks related to performing clinical studies; the risk that initial and interim results of a clinical study do not necessarily predict final results and that one or more of the clinical outcomes may materially change as patient enrollment continues, following more comprehensive reviews of the data, and as more patient data become available; potential delays in the commencement, enrollment and completion of clinical studies and the reporting of data therefrom; the risk that studies will not be completed as planned; the risk that the abstract will not be published as planned including delays in timing, format, or accessibility; and NKGen’s ability to raise additional funding to complete the development of its product candidates. Additional risks include uncertainties related to the Company’s acquisition of a majority interest in NKGen Biotech Korea Co., Ltd., including risks regarding the future performance of NKGen Biotech Korea Co., Ltd.’s business, the Company’s ability to successfully integrate NKGen Biotech Korea Co., Ltd.’s operations, personnel, and technologies, potential challenges in realizing expected synergies and cost savings, and risks that the Company may not achieve the anticipated strategic, financial, or operational benefits of the acquisition on the expected timeline or at all. These and other risks and uncertainties are described more fully under the caption “Risk Factors” and elsewhere in the Company’s filings and reports, which may be accessed for free by visiting the SEC’s website at www.sec.gov and on the Company’s website under the subheading “Investors—Financial and Filings”. Investors should take such risks into account and should not rely on forward-looking statements when making investment decisions. All forward-looking statements contained in this press release speak only as of the date on which they were made. The Company undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as required by law. Internal Contact: Denise Chua, MBA, CLS, MLS (ASCP) SVP, Corporate Affairs 949-396-6830 dchua@nkgenbiotech.com External Contact: Kevin Gardner Managing Director LifeSci Advisors, LLC kgardner@lifesciadvisors.com