Checkpoint blockade therapy (also called immune checkpoint inhibitors) is an cancer therapy that works (roughly speaking) by preventing the cancer from disabling the immune system. There's a list of major immune checkpoint inhibitors here: https://en.wikipedia.org/wiki/Checkpoint_inhibitor

A common issue with this kind of therapy is immune escape: the cancer mutates and escapes from the immune system in some other way, which makes the drug much less effective or even useless. You can read an overview of the topic here: https://sci-hub.se/10.1093/annonc/mdw217

This market resolves YES if any combination therapy is approved that:

• Reduces immune escape by >= 10 percentage points over the course of two years according to any metric in an associated publication.

• Increases long term survival rates (2 years) by >=10 percentage points, it is reported (by the developers of the drug) that this is believed to be due to preventing immune escape, and there is no published direct measure of immune escape.