Over the last couple of years we have heard much about targeting various checkpoints that exert an inhibitory effect on the immune system and the T cells, in particular.  The main targets where we have a growing body of evidence to date are CTLA-4, PD-1 and PD-L1, but there are others including LAG-3, TIM-3, ICOS etc.

Earlier this year at AACR, we saw new evidence that combining two checkpoints (anti-CTLA4 and anti-PD1) was superior to monotherapy in metastatic melanoma, albeit with a concomitant increase in toxicities.

What about the other inhibitory signals though?  Are they bystanders, much like passenger mutations that have little effect, or do they matter, at least in some tumor types?  If so, which ones?

We took a look at some of the emerging data associated with targeting TIM-3 – the results may well surprise some observers.