Altamira Therapeutics’ SemaPhore Delivery Platform Shows Significant Synergis-tic Effects of ZBTB46 mRNA with PD1 Immunotherapy in Control of Tumor Growth in Animal Model

HAMILTON, BERMUDA, March 22, 2023 (GLOBE NEWSWIRE) --

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• Preprint of results from animal study shows restriction of tumor growth in mice treated with ZBTB46 mRNA nanoparticles based on Altamira’s SemaPhore delivery technology
• Nanoparticle treatment combined with immune checkpoint inhibitor results in synergistic control of tumor growth

Altamira Therapeutics ("Altamira" or the "Company") (Nasdaq:CYTO), a company dedicated to developing RNA-based therapeutics that address important unmet medical needs, today announced the release of animal data by a Washington University School of Medicine (St. Louis, MO) research group showing restriction of tumor growth with a novel mRNA therapeutic delivered in nanoparticles based on the Company’s SemaPhore delivery platform.

Expression of the ZBTB46 gene with SemaPhore was associated with an immunostimulatory tumor microenvironment (TME), and it was potentiated when combined with anti-PD1 immune checkpoint inhibition. The manuscript describing the study is available on a preprint server¹ and has been submitted to a scientific journal for peer-review and potential publication.

The research group, led by Professor Kyunghee Choi of the Pathology & Immunology Department of Washington University, was interested in understanding the role that the ZBTB46 (Zinc Finger and BTB Domain Containing 46) gene plays in the microenvironment of tumors. The researchers found that tumor-derived factors frequently downregulate ZBTB46 resulting in a pro-tumor microenvironment, characterized by dysfunctional vasculature and immunosuppressive cell accumulation. In contrast, enforced ZBTB46 expression mitigated the pro-tumor TME features and restricted tumor growth, suggesting ZBTB46 as a potential target for tumor treatment.

In a next step, the group tested the systemic delivery of ZBTB46 mRNA with Altamira’s peptide-based SemaPhore nanoparticles in mouse models of sarcoma and metastatic breast cancer to boost ZBTB46 expression. The treatment sustained ZBTB46 expression in tumor-dendritic cells and -endothelial cells and resulted in the restriction of tumor growth associated with an immunostimulatory TME.

When combining nanoparticle treatment with an immune checkpoint inhibitor, the researchers reported that, “remarkably, the nanoparticles induced dramatic response in both anti-PD1-responsive […] and -refractory [..] tumor models following the treatment, generating long-term complete remission of tumor mass in many of the treated animals challenged with the anti-PD1-responsive [..] tumor.” They concluded that enforcing ZBTB46 expression promoted anti-tumor components in the TME, a prerequisite for effective immune checkpoint blockade therapy, and could be an effective adjuvant therapy with immunotherapy in cancer management.