Targeting myeloma essential genes using NOT Gated CAR T-cells, a computational approach.

Chimeric antigen receptor (CAR) T-cells have been transformational for myeloma therapy, but on-target/off-tumour toxicity has been troublesome, affecting all antigen targets. This complication is also a major limitation for the identification of novel targets. To understand the scale of the problem, we leveraged our previously published myeloma cell surface proteomics data. Strikingly, all myeloma surface proteins were also expressed on at least one essential tissue. Furthermore, of the thirty myeloma surface proteins with the lowest off-tumour expression, none had been previously targeted in myeloma, suggesting considerable untapped potential. In addition, NOT-gating has been proposed as a CAR T-cell design to improve targeting specificity, but identifying potential target combinations can be challenging without significant bioinformatic support. To facilitate researchers in their exploration of our data, we built a web app, NOTATER, that identifies a primary target according to user-defined criteria, plus inhibitory NOT-gate partners that can be paired with the target. Here, we illustrate the use of NOTATER, exploring targets essential for myeloma cell survival to minimize the risk of antigen escape. We identified the transferrin receptor plus 13 possible NOT-gate partners as a promising targeting strategy. We also demonstrate the potential of NOT-gating for improving the specificity of existing targets. ; Kay Kendall Leukaemia Fund