Company Announcements

SANTA ANA, Calif., June 12, 2024 (GLOBE NEWSWIRE) -- NKGen Biotech, Inc. (Nasdaq: NKGN) (“NKGen” or the “Company”), a clinical-stage biotechnology company focused on the development and commercialization of innovative autologous, allogeneic and CAR-NK natural killer (“NK”) cell therapeutics, today presented details on its novel allogeneic blood-derived NK cell therapy (“SNK02”) commercial manufacturing and cryopreservation process by Paul Y. Song, MD, Chairman and Chief Executive Officer of NKGen, entitled, “Protecting Patients by Removing Need for Lymphodepletion to Better Preserve Immune Function”. Dr. Song also provided an update on the Company’s initial Phase 1 results using SNK02 to treat patients with advanced refractory solid tumors.

Dr. Song’s presentation explored the potential benefits of eliminating pre-treatment lymphodepletion in patients undergoing SNK02 therapy, aiming to safeguard immune function and aid in recovery. Avoiding lymphodepletion before administering cancer treatment can provide many benefits including reduced toxicity, preservation of immune function and potentially enhancing treatment efficacy. The presentation also included a discussion on the results from the Company’s Phase 1 SNK02 clinical study in solid tumors previously disclosed in a publication at the 2024 American Society for Clinical Oncology annual meeting. Moreover, unpublished Phase 1 SNK02 data were also presented.

The Phase 1 clinical trial administered SNK02 intravenously (“IV”) weekly for a total of 8 weeks with a starting dose of 6 x 10⁹ SNK02 cells in patients with advanced refractory solid tumors, without lymphodepletion. The primary endpoint was safety based on adverse events, vitals, laboratory tests and physical exams. Tolerability and maximum tolerated dose were also evaluated. SNK02 was found to be well tolerated as a monotherapy and appears to have some clinical activity against pretreated solid tumors despite the lack of lymphodepletion.

Dr. Song commented during the presentation, “As most of the focus of NK cell therapy has been for liquid tumors with lymphodepletion, we have always believed that lymphodepletion could be detrimental to patients with solid tumors especially those being treated with immune checkpoint inhibitors, monoclonal antibodies or bispecific therapies where a robust immune response is essential. We therefore set out to develop a commercial scale manufacturing and cryopreservation process which could yield greater than 100,00 doses of SNK02 (cryopreserved enhanced activated allogeneic NK cells) with the idea that large doses could be delivered without lymphodepletion to potentially overcome any host versus graft reaction. We are pleased to show that, despite developing autoantibodies to sustained repeated dosing of our allogeneic product, SNK02 was safe and treatment appeared to stop the progression of several heavily pretreated solid tumors as a monotherapy. We are excited to further explore the efficacy of SNK02 in combination with immune checkpoint inhibitors and antibodies against solid tumors.”

Presentation Highlights:

• In the Phase 1 SNK02 clinical trial, 6 patients, with advanced refractory solid tumors and an average of 4 prior lines of therapy, were enrolled. The median age was 64 years old (range, 44–71), and 4 were male.
• The cancer subtypes included 2 colorectal cancers, 1 leiomyosarcoma, 1 angiosarcoma, 1 endometrial adenocarcinoma, and 1 undifferentiated pleomorphic sarcoma.
• Four of six patients completed 8 cycles of SNK02. The best objective response of stable disease (tumor stopped growing) was demonstrated in 100% of patients that completed the 8 cycles.
• One patient received 18 consecutive weekly doses and another patient received 12 consecutive weekly doses.
• Out of the 36 doses administered through Cycle 8, there were 17 Grade 1, 3 Grade 2, and 1 Grade 3 adverse events (“AEs”) related to investigational product (“IP”). The Grade 3 AE of increased fatigue resolved after 1 day with no intervention required.
• There was 1 death on study, which was deemed unrelated to the IP.
• Auto-antibodies appeared to develop around Cycle 5 and appeared to correlate with AEs.
• There did not appear to be any correlation with KIR mismatch or HLA subtyping with AEs or tumor response.
• SNK02 was well-tolerated as a monotherapy and appears to have some clinical activity against pretreated solid tumors despite the lack of lymphodepletion. SNK02 will continue to be studied as a monotherapy and in potential combination treatment regimens with monoclonal antibodies and immune checkpoint inhibitors.
  

A copy of the presentation is available on the Scientific Publications page of the Company’s website at https://nkgenbiotech.com/. Previously disclosed Phase 1 data on the positive effects of SNK02 on advanced solid tumors, which may not be included in this conference presentation, can also be found on the Scientific Publications page.

About SNK02
SNK02 is a novel cell-based, donor-derived ex vivo expanded allogeneic NK cell immunotherapeutic drug candidate. NKGen Biotech, Inc. is developing SNK02 for the treatment of a broad range of cancers.

About NKGen Biotech
NKGen is a clinical-stage biotechnology company focused on the development and commercialization of innovative autologous, allogeneic, and CAR-NK 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 Securities Exchange Act of 1934, as amended. 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 plans and expected timing for developing SNK01 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. 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 Securities and Exchange Commission’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, MT (ASCP)
Vice President, Investor Relations and Corporate Communications
949-396-6830
dchua@nkgenbiotech.com

External Contacts:
Chris Calabrese
Managing Director
LifeSci Advisors, LLC
ccalabrese@lifesciadvisors.com

Kevin Gardner
Managing Director
LifeSci Advisors, LLC
kgardner@lifesciadvisors.com