• SNK02 has the potential to be a first-in-class cryopreserved allogeneic NK cell therapy for solid tumors that does not require lymphodepletion before administration, which may lead to better overall synergy in future combination regimens with immune checkpoint inhibitors.
  
• In this Phase 1 trial, the best objective response of stable disease was demonstrated in 100% of patients that completed 8 treatment cycles of SNK02.
• SNK02 was well tolerated as a monotherapy and appears to have some clinical activity against pretreated solid tumors despite the lack of lymphodepletion.

SANTA ANA, Calif., May 23, 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 announced an online publication, titled “Interim Analysis of a Phase I Study using Cryopreserved Non-genetically Modified Allogeneic Natural Killer Cells With Enhanced Cytotoxicity (SNK02) in Patients with Advanced Solid Tumors without Lymphodepletion” at the 2024 American Society of Clinical Oncology (“ASCO”) Annual Meeting to be held virtually and at the McCormick Place Convention Center in Chicago, Illinois from May 31–June 4, 2024.

This Phase 1 clinical trial is a multi-center, open-label study evaluating the safety and tolerability of SNK02 in participants with pathologically confirmed solid tumors refractory to standard of care therapy. The study drug, SNK02, is a first-in-kind, cryopreserved allogeneic non-genetically modified NK cell product with significant anti-tumor cytotoxicity and over 90% expression of CD16, NKG2D, NKp46, and DNAM-1, that can be consistently produced on a large commercial scale. SNK02 was administered as an intravenous infusion (IV), weekly for eight weeks in patients with advanced solid tumors. The starting dose was 6x10⁹ SNK02 cells. We hypothesized that higher doses of SNK02 (to overcome autodigestion) could be delivered frequently without the need for lymphodepletion and that it might demonstrate activity against solid tumors that have failed multiple prior standard-of-care treatment options. The primary endpoint was safety based on adverse events (AEs), vitals, laboratory tests, and physical exams. Tolerability of SNK02 and maximum tolerated dose were also evaluated.

“Interim data from our Phase 1 clinical study utilizing our second NK cell therapy product, SNK02, demonstrated that the treatment was well-tolerated as a monotherapy in patients with solid tumors refractory to standard of care therapy,” said Paul Y. Song, MD, Chairman and CEO of NKGen. “We are particularly excited because SNK02 has the potential to be a first-in-class cryopreserved allogeneic NK cell therapy for solid tumors that does not require lymphodepletion before administration, which may lead to better overall synergy in future combination regimens especially with immune checkpoint inhibitors where a robust T-cell response is needed. Using our proprietary allogeneic manufacturing and cryopreservation processes, we are capable of producing hundreds of thousands of potential doses of enhanced NK cell therapies from materials collected from a single donor. Thus, our potential to treat a significant number of cancer patients with SNK02 is remarkably high. We are pleased to see such promising Phase 1 trial results for both of our unique cell therapy candidates: autologous SNK01 for neurodegenerative disease and allogeneic SNK02 for cancer.”

For additional information on the SNK02 clinical trial, please visit https://www.clinicaltrials.gov/ using the identifier NCT05990920.

Highlights from the online publication include:

• Five patients with advanced refractory solid tumors were enrolled in the trial.
• Patients had received an average of 4 lines of prior therapy.
• Median age was 64 (range 44 – 71) and 3 were male.
• The subtypes were 1 leiomyosarcoma, 1 angiosarcoma, 1 endometrial adenocarcinoma, 1 undifferentiated pleomorphic sarcoma, and 1 colorectal adenocarcinoma.
• Four of five 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.
• 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.
• 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 ePublication will be available on the Scientific Publications page of the Company’s website at https://nkgenbiotech.com/.

About SNK02

SNK02 is a novel cell-based, donor-derived ex vivo expanded allogeneic natural killer (“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, including the expected timing of completing and announcing further results from its ongoing clinical studies; statements regarding the Company’s plans and expected timing for developing 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:
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External Contacts:
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