RBI-1000

The immune cell-mediated elimination of clones expressing the acquired resistance mutations is predicted to prolong endocrine control of ER+BC, in an analogous manner to small molecule or monoclonal antibody targeted therapies, but with a more favorable dosing and adverse event profile due to precise immunologic targeting and no DDI. RBI-1000 is anticipated to enter clinical studies in the first half of 2024.

RBI-1000 is a candidate using a novel type of self-replicating RNA (srRNA) to generate robust immunity directed against acquired resistance mutations that develop in ER+ breast cancer (ER+ BC) in response to endocrine therapy...Priming of T cells against acquired mutations is also confirmed in human HLA-transgenic mice. The immune cell-mediated elimination of clones expressing the acquired resistance mutations is predicted to prolong endocrine control of ER+BC, in an analogous manner to small molecule or monoclonal antibody targeted therapies, but with a more favorable dosing and adverse event profile due to precise immunologic targeting and no DDI.