Sunday, December 21, 2014
SRS combined with anti-PD1 makes things better in ratties....this one's for you Artie!!!!
Stereotactic Radiation Therapy Augments Antigen-Specific PD-1 Mediated anti-Tumor
Immune Responses via Cross-Presentation of Tumor Antigen. Cancer Immunol Res. Sharabi, Mirschl, Kochel, et al. 2014 Dec19.
"The immune modulating effects of radiation therapy have recently gained considerable interest and there have been multiple reports of synergy between radiation and immunotherapy. ....we demonstrate the ability of stereotactic radiotherapy to induce endogenous antigen-specific immune responses when combined with anti-PD-1 checkpoint blockade immunotherapy. [In] small animal radiation research...image guided sterotactic radiotherapy to...melanoma or...breast [cancer] tumors resulted in development of antigen-specific T-cell and B-cell mediated immune responses. These immune-stimulating effects of radiotherapy were significantly increased when combined with either anti-PD-1 or regulatory T cell (Treg) depletion, resulting in improved local tumor control. ...radiotherapy increased the percentage of antigen-experienced T-cells and effector memory T-cells. ...radiotherapy up-regulates tumor associated antigen-MHC complexes, enhances antigen cross-presentation in the draining lymph node, and increased T-cell infiltration into tumors. These findings demonstrate the ability of radiotherapy to prime an endogenous antigen-specific immune response and provide additional mechanistic rationale for combining radiation with PD-1 blockade in the clinic."
Prior post with two articles noting synergistic benefit when radiation was combined with ipi: http://chaoticallypreciselifeloveandmelanoma.blogspot.com/2014/01/ipi-and-radiationa-good-combo-for.html
Individual patients, like dear Artie, seem to be experiencing this sort of effect when given radiation for pain control and other reasons, when already on or in rapid succession with immune therapy. Way to go, ratties....the big and little ones! Best wishes, Artie! You rock! - c