What are some strategies for enhancing local delivery of immunotherapy?

A significant drawback for current cancer treatments is system toxicity and side effects to the immune system. Focusing immunotherapy to the immediate tumor environment reduces toxicity and ensures that the immune response is focused only on the malignant tissue and the affected lymph nodes being drained. This can be achieved via intratumoral injections¹ which deliver drugs or genetically modified autologous immune cells right into the cancer milieu. Other strategies include designing immunotherapies that focus on molecular targets that are only found in the tumor microenvironment.² This can be facilitated by using microparticles loaded with immunomodulatory antibodies such as CTLA-4 which targets T-cells which are concentrated in the tumor environment.

References:
1. M.A. Aznar et al, "Intratumoral Delivery of Immunotherapy - Act Locally, Think Globally," J Immunol 198(1): 31-39, 2017.
2. M.A. Zhang et al, "Site-Specific Immunomodulators are Novel Immunotherapies for Cancer," J Immunol 196(S1): 214-220, 2016.