On May 14, 2026 Silexion Therapeutics Corp. (NASDAQ: SLXN) ("Silexion" or the "Company"), a clinical-stage biotechnology company pioneering RNA interference (RNAi) therapies for KRAS-driven cancers, reported positive preclinical findings from an ongoing translational immuno-oncology study evaluating its lead candidate, SIL204, in human KRAS-mutated pancreatic cancer cells. The study demonstrated a statistically significant increase in surface expression of major histocompatibility complex class I (MHC-I), also known as HLA-ABC, following treatment with SIL204 in human pancreatic cancer cells harboring the KRAS G12R mutation, as measured by flow cytometry.
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"These findings are particularly encouraging because they suggest SIL204 may influence biological pathways involved in the tumors evading the immune cells which are supposed to protect against the tumors, in addition to its previously demonstrated direct anti-tumor activity," said Ilan Hadar, Chairman and Chief Executive Officer of Silexion Therapeutics. "Checkpoint inhibitors have historically shown limited efficacy in pancreatic cancer in part because T cells often fail to adequately recognize these tumors. We believe the observed increase in MHC-I expression further supports an additional positive role of SIL204 in the area of immunotherapy which could facilitate positive outcomes in the treatment of pancreatic cancer."
MHC-I is essential for enabling cytotoxic T cells to recognize and attack tumor cells. Loss or suppression of MHC-I expression is widely recognized as a key mechanism by which tumors evade immune detection and resist immune-mediated destruction. Research has shown that oncogenic KRAS signaling contributes to immune evasion through suppression of antigen presentation and impairment of T-cell recognition pathways in pancreatic cancer and other KRAS-driven tumors.
Pancreatic cancer remains among the most immunologically resistant solid tumors and has historically demonstrated limited responsiveness to immune checkpoint inhibitor therapies such as anti-PD-1 agents, including pembrolizumab (Keytruda), outside of select biomarker-defined patient populations. By increasing MHC-I expression, SIL204 may help restore immune visibility of KRAS-mutated tumor cells, potentially supporting future therapeutic strategies designed to enhance responsiveness to PD-1/PD-L1 blockade.
Published research has increasingly highlighted the relationship between KRAS signaling, antigen presentation, and immune checkpoint resistance, with multiple recent studies suggesting that reversing KRAS-associated immune suppression may improve immune-mediated anti-tumor activity.
(Press release, Silexion Therapeutics, MAY 14, 2026, View Source [SID1234665741])