New combination immunotherapy for melanoma and breast cancer
Source: Medical University Of Vienna, January 2025
(Vienna, 23 January 2025) A research team at the Medical University of Vienna led by Maria Sibilia has investigated a new combination therapy against cancer. This therapy employs systemic administration of the tissue hormone interferon-I combined with local application of Imiquimod. This combination showed promising results in topically accessible tumors like melanoma and breast cancer models: The therapy led to the death of tumor cells at the treated sites and simultaneously activated the adaptive immune system to fight even distant metastases. The results published in the top journal Nature Cancer could improve the treatment of superficial tumors such as melanoma and breast cancer.
In recent years, immunotherapies have had significant success in the treatment and cure of a wide range of cancers. However, for some patients, these agents are still not sufficiently effective. As part of a preclinical study, Maria Sibilia, Head of the Center for Cancer Research at the Medical University of Vienna, therefore investigated the effects of a combination immunotherapy consisting of systemic administration of the tissue hormone interferon (IFN)-I and local imiquimod therapy. Imiquimod is an active substance that activates the innate receptors TLR7/8 and used to treat basal cell carcinomas. The researchers employed various preclinical mouse tumor models of melanoma and breast cancer. What both tumors have in common is that they are accessible to local therapy and often form distant metastases.
Effective for local tumors and distant metastases
Immunotherapies use the body’s own immune system to fight cancer cells. Plasmacytoid dendritic cells (pDCs), which are activated by Imiquimod via TLR7/8, play an important role in this process. The study showed that oral imiquimod stimulates pDCs to produce the tissue hormone IFN-I. This sensitized other dendritic cells and macrophages in the tumor environment to topical imiquimod therapy, which inhibited the formation of new blood vessels via the cytokine IL12 leading to the death of tumor cells.