Do tumors develop resistance to immunotherapies?

Yes, just as tumors are able to develop resistance to chemotherapies, tumors can also develop resistance to immunotherapies. How resistance builds is a matter currently under investigation. There is some evidence to suggest that resistance is an adaptation controlled by epigenetic modifications to the cancer cell genome.1 Other researchers have identified the apoptosis of tumor-infiltrating lymphocytes as playing a causative role.2 As new research continues, it’s likely that research will uncover several mechanisms by which tumors work to evade the activity of anticancer immunotherapies. Only once the causes of resistance are fully understood and mitigated will immunotherapy reach its fullest potential.

1. D. Zingg, et al., “The Histone Methyltransferase Ezh2 Controls Mechanisms of Adaptive Resistance to Tumor Immunotherapy,” Cell Rep 20 (4):854, 2017.
2. J. Zhu, et al., “Resistance to cancer immunotherapy mediated by apoptosis of tumor-infiltrating lymphocytes,” Nat. Comm 8:1404, 2017.