Radiation Therapy Plus Anti-Programmed Death Ligand 1 Immunotherapy: A Review on Overall Survival.
OBJECTIVE
To analyze current preclinical trials and early clinical trials on the effects of concomitant anti-programmed death ligand 1 (anti-PD-L1) immunotherapy and radiation therapy on progression-free survival (PFS) and overall survival (OS) for advanced melanoma and metastatic non-small cell lung cancer (NSCLC) patients.


METHODS
A literature review was conducted to find current articles about radiation and anti-PD-L1 combinatorial therapy to gain knowledge about T-lymphocyte (T-cell) mediated immune responses, preclinical mouse tumor trials, and early clinical trials.


RESULTS
Several preclinical studies involving mice tumor strains and 2 early clinical trials observed an increase in PFS and OS when testing radiation therapy given in combination with anti-PD-L1 immunotherapy. Abscopal effects of tumor regression and control were notable in some studies.


CONCLUSIONS
Low doses of radiation enhance the immune system by increasing T-cell activity. Radiation also increases levels of PD-L1 that inhibit tumor-fighting capabilities of T-cells. Anti-PD-L1 immunotherapy given in combination with radiation therapy has been tested in preclinical studies and hypothesized to increase PFS and OS in patients with advanced melanoma and metastatic NSCLC.


CONCLUSIONS
Anti-PD-L1 immunotherapy boosts the immune effects of radiation therapy on tumor regression by eradicating the limiting effects of PD-L1 on the immune system. The combination therapies have the potential to benefit metastatic patients who qualify for the treatment.
Elizabeth Marie
EM
Krcik
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D059248:Chemoradiotherapy / Q000401:mortality* / Q000706:statistics & numerical data; D006801:Humans; D051379:Mice; D009369:Neoplasms / Q000276:immunology / Q000401:mortality* / Q000628:therapy*; D015995:Prevalence; D013045:Species Specificity; D015996:Survival Rate; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C000594389:atezolizumab
anti-PD-L1 therapy; metastatic melanoma; metastatic non-small cell lung cancer; nivolumab; preclinical studies; radiation therapy