Date Published: January 13, 2019
Publisher: John Wiley and Sons Inc.
Author(s): Yu Mi, C. Tilden Hagan, Benjamin G. Vincent, Andrew Z. Wang.
Cancer immunotherapy has achieved remarkable clinical efficacy through recent advances such as chimeric antigen receptor‐T cell (CAR‐T) therapy, immune checkpoint blockade (ICB) therapy, and neoantigen vaccines. However, application of immunotherapy in a clinical setting has been limited by low durable response rates and immune‐related adverse events. The rapid development of nano‐/microtechnologies in the past decade provides potential strategies to improve cancer immunotherapy. Advances of nano‐/microparticles such as virus‐like size, high surface to volume ratio, and modifiable surfaces for precise targeting of specific cell types can be exploited in the design of cancer vaccines and delivery of immunomodulators. Here, the emerging nano‐/microapproaches in the field of cancer vaccines, immune checkpoint blockade, and adoptive or indirect immunotherapies are summarized. How nano‐/microparticles improve the efficacy of these therapies, relevant immunological mechanisms, and how nano‐/microparticle methods are able to accelerate the clinical translation of cancer immunotherapy are explored.
Adoptive cell therapy (ACT) is defined as expanding tumor‐specific T cells isolated from a patient’s peripheral blood or tumor biopsies ex vivo, culturing with stimuli or genetically engineering the cells, and then infusing them back into patients for cancer treatment.163, 164, 165, 166 It is one of the most effective therapies for patients suffering metastatic melanoma with an approximate objective cancer regression rate of 50%.167 This ex vivo activation process for tumor‐specific T cells bypasses normal tumor immunosuppression in vivo and avoids systematic autoimmune reactions.167, 168 However, the objective response rate of ACT in solid tumors remains low. This is due to the immunosuppressive TME deactivating ACT‐produced T cells after infusion. Therefore, persistence of T‐cell activation within the tumor microenvironment is important to improve the overall efficacy of ACT.
Cancer immunotherapy is making rapid progress with many preclinical technologies translating into clinical practice. With the same momentum, some nano‐enabled cancer immunotherapy treatments are already under clinical investigation. These include nanoparticle formulations of STING agonists and nanoparticle formulations of mRNA cancer vaccines. Based on the robust preclinical data, there is reason for high enthusiasm for the success of these treatments.
The authors declare no conflict of interest.