First-in-human phase 1/2 study (MYCHELANGELO I) of first-in-class epigenomic controller OTX-2002 targeting MYC oncogene in patients with hepatocellular carcinoma (HCC) and other solid tumors.

606 Background: The c-MYC (MYC) oncogene is a master transcription factor of tumor cell and microenvironment regulation; it is often dysregulated in cancer, including HCC. OTX-2002 is a MYC-targeted Epigenomic Controller (MYC-EC), an mRNA drug substance encapsulated in a clinical lipid nanoparticle (LNP), designed to downregulate MYC expression pre-transcriptionally with high specificity and durability, inhibiting tumor cell viability while sparing normal cells. Methods: A first-in-human dose-escalation study (NCT05497453) investigates OTX-2002 monotherapy in HCC and other solid tumors. Key outcomes include safety, tolerability, pharmacokinetics (PK) and the recommended dose for expansion. In addition to standard safety measures, LNP-associated safety measures including cytokine profiling and an assessment of the presence of anti-PEG antibodies (ADA) were included. Initial pharmacodynamic activity (PD) was assessed via measurement of DNA methylation at the MYC locus in cell-free DNA [cfDNA] from whole blood. Results: As of August 23, 2024, 24 patients were treated at 6 doses (19 HCC, 1 colorectal, 1 cervical, 1 pancreatic, 2 sarcoma). OTX-2002 was generally well-tolerated; most adverse events (89%) were low grade, with infusion-related reactions being the most common (30%). Consistent with known LNP profiles, OTX-2002 adverse events were transient and manageable, including cytokine and ADA expression levels. Plasma PK exposures of OTX-2002 were linear across the first five doses analyzed. Significant, on-target dose-dependent changes in MYC gene methylation were seen in cfDNA for all patients post-dose and were durable for at least 15 days, consistent with the designed durability of the MYC-EC. Updated data will be presented. Conclusions: OTX-2002 is well-tolerated and induces rapid and durable epigenomic changes to the MYC locus. These results provide clinical proof of mechanism of the epigenomic controller platform and support continued development of OTX-2002. Clinical trial information: NCT05497453 .