Recent Developments in Cancer Immunotherapy

Recent advances in cancer immunotherapy, such as immune checkpoint inhibition, chimeric antigen receptor T-cell therapy, and cancer vaccination, have changed the field of cancer treatments with profound success in a few cancer types.

FREMONT, CA: Immunotherapy uses a patient’s immune system to target cancer and has resulted in novel therapeutic approaches and unprecedented clinical outcomes. Despite immunotherapeutic methods finding success in a variety of cancer subtypes and clinical scenarios, there are various challenges. Therefore, comprehensive knowledge of how these therapies operate is essential to addressing these issues. Tumour-host immune system interactions are heterogeneous, and few characteristics can predict immunotherapy responsiveness. The tumour microenvironment (TME), affects immunotherapeutic response and immune evasion. A profound understanding of host-tumour interactions is critical to promoting the development of novel and more effective immunotherapies.

Immune checkpoint inhibitors (ICI) are an efficient type of cancer immunotherapy. ICI therapy is based on the premise that T cells contain evolutionarily conserved negative regulatory markers acting as checkpoints to regulate activation. Treatment with immune checkpoint inhibitors, inhibition is released, and cancer cells are targeted and destroyed by the primed and activated cytotoxic T cells. ICI has shown successful treatment for a variety of recalcitrant cancers.

ICI has achieved marked success in patients with previously dismal outcomes treated with conventional cancer therapies, like chemo, radiation, and targeted therapy. Durable responses indicate long-lasting immunological memory can be observed and established in patients responding to ICI.

Over the last decade, cancer immunotherapy has markedly changed how cancer patients are treated. Immunotherapeutic modalities have found great success in various settings and patients with previously refractory diseases. Further study of alternative checkpoint inhibitor pathways allowing for tumour escape and understanding the TME’s suppressive effect on ICI are significant areas of study required to develop more successful ICI therapies. CAR T-cell therapy (CART) is effective in subsets of patients with hematologic malignancies but not for patients with highly immunosuppressive TME or with solid tumours.

Targeting the immunosuppressive elements of the TME, including TAMs, has shown promise in enhancing ICI and CART efficacy. Clinical studies leveraging these agents as preconditioning or in a combination with ICI and CART will be required to determine which methods show the most efficiency. Targeting alternative pathway elements with ICI has shown promise and will lead to new combination therapies. Novel engineering of CART to allow for improved CART trafficking and reduced immunosuppression within solid tumours will eventually allow for advanced outcomes to be achieved. Cancer vaccines have made great strides in recent years, especially studies using neoantigen vaccines in combination with TME targeting, which has the potential to open up this exciting domain. Cancer immunotherapy is a modality emerging as critical to the treatment of the majority of cancers. A continued focus on basic immuno-oncology research will drive the ability to develop new therapies in the field and continue to build on the successes achieved with cancer immunotherapy.