Genentech finds non-exhausted antitumor T cell source in blood, plus updates on Penn and Chordoma Foundation-Mark Foundation

Genentech identifies blood as source of antitumor T cells
In a Nature article, a Genentech Inc. team reported that non-exhausted T cell clones in the blood could act as a source of antitumor T cells that checkpoint inhibitors could stimulate. Concurrent expansion in tumors and adjacent normal tissues by clonal T cells, determined by single-cell RNA sequencing, was associated with improved progression-free survival (PFS) in Tecentriq atezolizumab-treated patients with various cancers. The team, which included VP of Research Oncology Ira Mellman, showed that clones of non-exhausted T cell clones that expanded in tumors after treatment were present in pretreatment blood samples. Blood-associated T cell clones were less likely than tumor-associated ones to be exhausted, and they suggested that the intratumoral T cells were continually replenished from the blood.

Genentech and other groups have been using circulating T cells as a potential sources of neoantigen-specific TCRs to design cell therapies for cancer (see “Personalized TCR Therapies”)...