An important requisite for immune checkpoint blockade efficacy is the presence of T cells in the tumor microenvironment. Many tumors however, such as ovarian and prostate, are immune deserts (cold) and hence nonresponsive to such treatment.
In a recent study, published in Cancer Discovery*, researchers have found that low-dose irradiation can inflame advanced cold tumors in mouse models and, when combined with immunotherapy, induce simultaneous mobilization of adaptive and innate immunity and tumor eradication.
In a subsequent clinical trial (RACIN; NCT03728179) held at the Lausanne University Hospital (CHUV), patients with metastatic immune-cold tumors showed similar mobilization of adaptive and innate immunity after low dose radiation, and significant responses following combination of low dose radiation with immunotherapy.
"This novel treatment strategy combining radiation therapy with immunotherapy in patients with advanced prostate cancer holds promise for optimizing immunotherapy, which may lead to long lasting tumor remission and cures,” said Howard R. Soule, Executive Vice President and Chief Science officer of the Prostate Cancer Foundation, one of the supporting insitutions of this research. “PCF commends Pr Coukos’ team for this advancement in precision medicine and proudly supports their work to bring us closer to our mission to eliminate death and suffering from prostate cancer.”
The first author of this study, Dr Fernanda G. Herrera, an attending physician in the services of radio-oncology and immuno-oncology at the Lausanne University Hospital, conducted the preclinical work in collaboration with Dr Catherine Ronet and many others in the Human Immunology Discovery Engine (Hi-TIDe) labs under the supervision of Pr George Coukos and Dr Melita Irving. The Hi-TIDe is part of the Ludwig Lausanne branch. Dr Herrera served later also as the principal investigator of the clinical study conducted in the Service of immuno-oncology, directed by Pr Coukos.
The research was supported by the Ludwig Institute for Cancer Research, and grants to George Coukos from: Bristol-Myers Squibb, the Prostate Cancer Foundation Challenge Award, and the Cancera, Biltema and Paul Matson Foundations.
* Low Dose Radiotherapy Reverses Tumor Immune Desertification and Resistance to Immunotherapy