Press releases

STORM Therapeutics Presents New Clinical Data on its First-in-Class METTL3 Inhibitor STC-15 at SITC 2024

STC-15 is well tolerated and demonstrates promising signs of clinical activity observed in multiple tumor types

Gene expression data shows upregulation of innate immunity pathways

Tumor regressions observed at all dose levels, 60-200 mg TIW

11 November 2024, Cambridge, UK: STORM Therapeutics Ltd. (STORM), the clinical stage company pioneering cellular reprogramming through RNA modifications to treat disease, today announces that it presented promising data from its Phase 1 clinical study evaluating its METTL3 RNA methyltransferase inhibitor, STC-15, at the Society of Immunotherapy for Cancer (SITC) 39th Annual Meeting, held in Houston, US, from 6-10 November 2024.

The Phase 1 clinical study enrolled 42 patients across five dose escalation cohorts ranging from 60mg to 200mg and explored daily and thrice weekly oral dosing regimens. Data presented at SITC follows the Company’s presentation at the 36th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics in October 2024.

The presentation at SITC titled, ‘Phase 1 dose escalation and cohort expansion study evaluating safety, PK, PD and clinical activity of STC-15, a METTL3 inhibitor, in patients with advanced malignancies’, showed:

  • Gene expression pathways related to Interferon (IFN) signalling, response to virus and dsRNA binding were enriched in patients with longer duration of STC-15 treatment
  • Tumor regressions were achieved at all dose levels, 60 mg - 200 mg three times a week (TIW), with three sustained Partial Responses (PRs) at 60 mg, 100 mg, and 200 mg TIW in multiple tumor types
  • Treatment emergent adverse events, including target-related AE’s (e.g. platelet reductions, rash, pruritis) were mainly mild, transient and well managed with supportive care and were not treatment limiting
  • No maximum tolerated dose established up to 200 mg TIW
  • Evidence of M1 macrophages in the TME, consistent with preclinical data
  • Robust METTL3 target engagement indicated by rapid and long-lasting m6A inhibition

Kyriakos P. Papadopoulos, Co-Director of Clinical Research at START San Antonio, principal investigator for the STC-15 Phase 1 study and lead author of the SITC presentation, said: “The ability to activate the innate immune system while maintaining tolerability and efficacy is what is truly unique about STC-15. STC-15 targets METTL3, initiating a novel immunologic mechanism that demonstrates remarkable safety for an immuno-oncology drug. The early efficacy and safety data in the advanced cancer setting supports further clinical development in Phase 2, in multiple tumor types.”

Jerry McMahon, Chief Executive Officer at STORM Therapeutics, said: “STC-15 is first in its class – first to target METTL3, and first to target a RNA methyltransferase. We are pleased to report encouraging signs of clinical activity and corresponding upregulation of the gene pathways associated with the METTL3 mechanism of action. We look forward to developing and progressing our product into a Phase 2 study following these positive results.”

CONTACTS:

STORM Therapeutics Ltd
Tel: +44 (0)1223 804174
info@stormtherapeutics.com

Optimum Strategic Communications
Hana Malik, Zoe Bolt, Elena Bates
Tel: +44 (0)203 882 9621
storm@optimumcomms.com

NOTES TO EDITORS

About STORM Therapeutics

STORM Therapeutics is a clinical-stage biotechnology company pioneering cellular reprogramming through RNA modifications to treat disease. Its world leading understanding of RNA modifying enzymes (RME) has led to the discovery of breakthrough small molecule drugs that precisely reprogram cells through RNA biology for the treatment of cancer, inflammation, viruses and CNS diseases.

STORM’s lead product, STC-15, is the first RNA modifying enzyme inhibitor to enter human clinical development. STC-15 is currently being evaluated in a Phase 1 study in patients with advanced solid tumors, establishing a data set allowing development in future clinical studies. Preclinical data have revealed that METTL3 inhibition stimulates immune cells and activates interferon pathways, leading to the destruction of tumor cells. Additional preclinical studies have demonstrated enhanced anti-tumor properties in combination with checkpoint inhibitors, supporting clinical development in tumor types where an augmented immune response may result in anti-cancer activity.

STC-15 has also been shown preclinically to inhibit tumor growth through mechanisms involving anti-cancer immune responses, such as changes in interferon signaling and constructive interaction with T cell checkpoint blockade.

STORM is studying the safety and pharmacology of STC-15 in a Phase 1 clinical study in patients with solid tumors. Details of the study can be found on clinicaltrials.gov under the identifier NCT05584111.

About SITC Annual Meeting

The Society for Immunotherapy of Cancer Annual Meeting is the largest cancer immunotherapy conference, hosted by the leading member-driven organization focused on cancer immunotherapy, SITC. The Annual Meeting brings together international leaders from academia, regulatory and government agencies, as well as industry representatives for unmatched education, scientific exchange and networking with the scientists driving the field.