Racura Oncology Unveils Mechanism Behind MYC Gene Silencing by (E,E)-bisantrene at AACR 2026

Preclinical Data Illuminates (E,E)-bisantrene’s Targeted Action on MYC Gene

Racura Oncology (ASX:RAC) has presented compelling preclinical evidence at the 2026 American Association of Cancer Research (AACR) Annual Meeting that its lead compound, (E,E)-bisantrene, silences the notorious cancer driver gene MYC by stabilising a G-quadruplex (G4) DNA structure in the gene’s promoter region. This mechanism underpins the drug’s anticancer activity and bolsters confidence in its clinical development trajectory.

Dr Sumit Sahni, Racura’s senior scientist, showcased data revealing that (E,E)-bisantrene binds with high affinity to the c-MYC G4 DNA, stabilising this secondary structure and effectively downregulating MYC gene expression in breast and lung cancer cell lines. The findings extend beyond simple binding, with RNA sequencing showing broad transcriptomic shifts consistent with potent MYC suppression.

Molecular Insights Confirm Specific Binding and Stabilisation

Advanced techniques including nuclear magnetic resonance spectroscopy and surface plasmon resonance quantified the interaction between (E,E)-bisantrene and the c-MYC G4 structure. The drug binds in a 2:1 stoichiometry, stacking on both ends of the G-tetrads, with a roughly 1.5-fold preference over mutant double-stranded DNA sequences. Circular dichroism spectroscopy further confirmed that (E,E)-bisantrene dose-dependently increases the melting temperature of the G4 structure, a hallmark of stabilisation.

This detailed molecular characterisation aligns with Racura’s previous patent filings, which secure 20 years of intellectual property protection for (E,E)-bisantrene’s composition and mechanism. The company’s strategic collaborations with institutions such as the University of Wollongong and Purdue University underpin this sophisticated research effort.

Clinical Trials Progress Amid Growing Scientific Validation

The preclinical data arrives as Racura advances multiple clinical programs. Notably, the Phase 1 HARNESS-1 trial is testing RC220, Racura’s proprietary formulation of (E,E)-bisantrene, in combination with osimertinib for EGFR-mutant non-small cell lung cancer (NSCLC). This trial recently enrolled its first patient, marking a critical step in evaluating the drug’s potential to overcome resistance to current therapies.

The gene silencing mechanism detailed at AACR reinforces the rationale behind this trial and others, including a Phase 3 study in acute myeloid leukaemia (AML) and a Phase 1a/b study combining (E,E)-bisantrene with doxorubicin to enhance anticancer effects while potentially offering cardioprotection. The RNA sequencing data also showed that (E,E)-bisantrene’s transcriptomic profile closely resembles that of CX-5461, another investigational G4-binding agent, suggesting a shared therapeutic pathway.

These developments follow Racura’s recent first patient recruited milestone in the lung cancer trial, underscoring momentum in translating preclinical promise into clinical evaluation.

Implications for Investors and the Oncology Landscape

While the preclinical findings offer valuable insights into (E,E)-bisantrene’s mode of action, the ultimate impact hinges on forthcoming clinical trial outcomes. The detailed mechanism supports the drug’s differentiation in a competitive oncology market increasingly focused on targeting oncogene regulation via non-traditional DNA structures. Racura’s ongoing investment in intellectual property and clinical programs positions it to potentially capitalise on these advances, though clinical efficacy and safety data remain pivotal.