NKGen Biotech, Inc. 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.

The company 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. 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.

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.