Silexion Therapeutics Reports Positive Preliminary Immunotherapy Findings for SIL204 in KRAS-Driven Pancreatic Cancer
Rhea-AI Summary
Silexion Therapeutics (NASDAQ: SLXN) reported positive preclinical immuno-oncology data for its RNAi candidate SIL204 in KRAS-driven cancers.
In human KRAS G12R-mutated pancreatic cancer cells, SIL204 produced a statistically significant increase in surface MHC-I (HLA-ABC) expression, and similar effects were seen in KRAS-mutated non-small cell lung cancer cells, supporting potential future evaluation with anti-PD-1 therapies such as pembrolizumab (Keytruda).
AI-generated analysis. Not financial advice.
Positive
- Statistically significant MHC-I increase in KRAS G12R pancreatic cancer cells after SIL204
- MHC-I upregulation also observed in KRAS-mutated non-small cell lung cancer cells
- Findings support potential future combinations with anti-PD-1 therapies, including pembrolizumab
- Data add an immunotherapy mechanism to SIL204 beyond direct anti-tumor activity
Negative
- Findings are preliminary and limited to preclinical studies in cancer cell models
News Market Reaction – SLXN
On the day this news was published, SLXN declined 9.31%, reflecting a notable negative market reaction. Argus tracked a trough of -62.4% from its starting point during tracking. Our momentum scanner triggered 21 alerts that day, indicating elevated trading interest and price volatility. This price movement removed approximately $230K from the company's valuation, bringing the market cap to $2.24M at that time. Trading volume was exceptionally heavy at 16.3x the daily average, suggesting significant selling pressure.
Data tracked by StockTitan Argus on the day of publication.
Key Figures
Market Reality Check
Peers on Argus
Momentum scanner flagged 2 biotech peers moving up (median ~5.9%), while SLXN was down 5.01% and trading near its 52-week low. This points to stock-specific pressure despite broader small-cap biotech strength.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| May 13 | Clinical manufacturing | Positive | -5.0% | GMP clinical batch manufacturing and new Phase 2/3 trial approval. |
| Apr 28 | Trial application | Positive | -12.8% | Phase 2/3 trial application submission to Germany’s BfArM for SIL204. |
| Mar 24 | Trial approval | Positive | +5.5% | Israeli Ministry of Health approval to initiate Phase 2/3 trial. |
| Mar 17 | Earnings update | Positive | -1.9% | Q4/FY 2025 results and business update including SIL204 progress and cash. |
| Mar 05 | Shareholder meeting | Neutral | -1.8% | EGM call to increase authorized share capital and equity incentive pool. |
SLXN often traded lower following positive development or financing-related updates, with one notable upside move on a major clinical approval.
Over the last few months, SLXN has advanced SIL204 from toxicology completion into a planned Phase 2/3 program, securing Israeli Ministry of Health approval on Mar 24, 2026 and subsequent German and ethics approvals. Despite these generally positive milestones, shares fell after several updates, including the Apr 28 BfArM submission and the May 13 GMP manufacturing news. A March extraordinary meeting sought a large increase in authorized share capital, underscoring ongoing financing and dilution considerations alongside the clinical progress.
Regulatory & Risk Context
An effective Form S-3 resale registration filed on Oct 31, 2025 covers existing holder shares and warrants; SLXN would receive up to $4.9 million only if 344,063 registered warrants are exercised for cash, while share sales themselves do not generate proceeds for the company.
Market Pulse Summary
The stock moved -9.3% in the session following this news. A negative reaction despite positive preclinical data fits prior instances where SLXN traded lower after constructive clinical updates and financing steps. The stock already sat 97.54% below its 52-week high at $0.55 and well under the $3.11 200-day MA, with warrant registrations for up to 2,710,945 shares and a large authorized share increase to 59,000,000 highlighting dilution risk that could have overshadowed early-stage efficacy signals.
Key Terms
rna interference (rnai) medical
kras medical
mhc-i medical
hla-abc medical
flow cytometry medical
checkpoint inhibitors medical
anti-pd-1 medical
pd-1/pd-l1 blockade medical
AI-generated analysis. Not financial advice.
Preliminary results from a preclinical study demonstrated statistically significant increase in MHC-I expression following SIL204 treatment in human pancreatic and non-small cell lung cancer cells harboring a KRAS mutation, supporting potential future evaluation alongside anti-PD-1 therapies including pembrolizumab (Keytruda®)
Grand Cayman, Cayman Islands, May 14, 2026 (GLOBE NEWSWIRE) -- Silexion Therapeutics Corp. (NASDAQ: SLXN) ("Silexion" or the "Company"), a clinical-stage biotechnology company pioneering RNA interference (RNAi) therapies for KRAS-driven cancers, today announced 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.
“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.1
Image Caption: SIL204 increases surface MHC-I (HLA-ABC) expression in human KRAS G12R-mutated pancreatic cancer cells (KP2-G12R) at 60 nM, as measured by flow cytometry. *P<0.05 vs. control.
About Silexion Therapeutics
Silexion Therapeutics is a pioneering clinical-stage, oncology-focused biotechnology company dedicated to the development of innovative treatments for unsatisfactorily treated solid tumor cancers that have the mutated KRAS oncogene, generally considered to be the most common oncogenic gene driver in human cancers. The Company conducted a Phase 2a clinical trial in its first-generation product, which showed a positive trend in comparison to the control of chemotherapy alone, and is currently advancing its lead, second-generation, product candidate, SIL204, a small interfering RNA (siRNA), towards clinical trials in Israel and the European Union. Silexion is committed to pushing the boundaries of therapeutic advancements in the field of oncology and further developing its lead product candidate for locally advanced pancreatic cancer. For more information, please visit: https://silexion.com
Notice Regarding Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the federal securities laws. All statements other than statements of historical fact contained in this communication, including statements regarding the therapeutic potential, immune-modulating activity, mechanism of action, translational significance, future development, and planned studies relating to SIL204, including its potential role in modulating antigen presentation, restoring immune recognition, enhancing responsiveness to checkpoint inhibitor therapies, and future immuno-oncology or combination applications, are forward-looking statements. These forward-looking statements are generally identified by terminology such as "may", "should", "could", "might", "plan", "expect", "intend", "will", "estimate", "anticipate", "believe", "predict", or "potential", or the negatives of these terms or variations of them or similar terminology. Forward-looking statements involve a number of risks, uncertainties, and assumptions, and actual results or events may differ materially from those projected or implied in those statements. Important factors that could cause such differences include, but are not limited to: (i) Silexion's ability to successfully complete preclinical studies and initiate and conduct clinical trials, including the Phase 2/3 trial of SIL204 in locally advanced pancreatic cancer; (ii) Silexion's strategy, future operations, financial position, projected costs, prospects, and plans; (iii) the impact of the regulatory environment and compliance complexities, including the outcome of the CTA’s review of the Company’s application to commence clinical trials in Germany and other jurisdictions, as well as site-level approvals, conditions and clearances (including outstanding regulatory forms and any initial participant caps) required prior to study commencement at each clinical site; (iv) expectations regarding future partnerships or other relationships with third parties; (v) Silexion's future capital requirements and sources and uses of cash, including its ability to obtain additional capital; (vi) Silexion's ability to maintain its Nasdaq listing; and (vii) other risks and uncertainties set forth in the documents filed by the Company with the SEC, including the Company's Annual Report on Form 10-K for the year ended December 31, 2025. Silexion cautions you against placing undue reliance on forward-looking statements, which reflect current beliefs and are based on information currently available as of the date a forward-looking statement is made. Forward-looking statements set forth herein speak only as of the date they are made. Silexion undertakes no obligation to revise forward-looking statements to reflect future events, changes in circumstances, or changes in beliefs, except as otherwise required by law.
Company Contact
Silexion Therapeutics Corp
Ms. Mirit Horenshtein Hadar, CFO
mirit@silexion.com
Investor Relations Contact
Arx Investor Relation
North American Equities Desk
silexion@arxhq.com
1 See Bear AS et al., Cancer Cell (2020); Canon J et al., Nature (2019)
