FTM thanks for the more detailed explanation. I think SK and the company IR people are trying to find ways to simplify the explanation so non-experts can understand the MOA. The human immune system is extremely complex and we are fortunate to be living in the generation where our understanding of the immune system is increasing exponentially. I agree with those who say that the new visuals on the website are very helpful in helping us understand the upstream/downstream relationship of BAVI to the immune system.
FTM-- Thanks for this clarity on difference between Bavi's upstream MOA and PD-1/ PD-L1 downstream MOA.
I think the Company has adopted the "checkpoint" terminology because that is the buzz word everyone is using these days when discussing immnotherapies. In fact, however, as your post makes clear, a car-driving metaphor would work better.
IMO, it would be clearer to say that the MOA / "checkpoint" of downstream immunotherapies like PD-1/ PD-L1 functions by taking the foot off the brakes while the MOA / checkpoint of Bavi functions by putting the foot on the accelerator.
The downstream MOAs of PD-1 and CTLA-4 remove blocks that are holding killer T-Cells in check.