Table 1.

Terminology for different resistance mechanisms to immunotherapy

Term	Description
Primary resistance	A clinical scenario where a cancer does not respond to an immunotherapy strategy. The mechanistic basis of lack of response to immunotherapy may include adaptive immune resistance
Adaptive immune resistance	A mechanism of resistance where a cancer is recognized by the immune system but it protects itself by adapting to the immune attack. Given the evolving nature of the immune/cancer cell interaction, this could clinically manifest as primary resistance, mixed responses or acquired resistance
Acquired resistance	A clinical scenario in which a cancer initially responded to immunotherapy but after a period of time it relapsed and progressed