Microbiome Immunotherapy Toxicity and Response Evaluation

The gastrointestinal microbiome of a healthy individual is comprised of many hundreds of bacteria species and thousands of bacteria strains. The composition of bacteria in an individual's microbiome can change over time and this can be influenced by factors including diet, drugs, genetics and infection. These bacteria play a central role in digestion of food, development and regulation of our immune system as well as our resistance to pathogens. Recent evidence suggest that a patient's intestinal microbiota composition plays a critical, though as yet poorly defined, role in determining both therapeutic efficacy and likelihood of significant adverse events to T-cell checkpoint inhibitor immunotherapy. Immune checkpoint inhibitors are revolutionising treatment of many types of metastatic cancer, including melanoma, renal and non-small cell lung cancer, in the expectation of improving patient overall survival. However, they have limitations as they do not work for all patients and can cause unpredictable, complex immune-related toxicities. The investigators will perform a detailed study of cancer patients receiving checkpoint inhibitors. Saliva and a series of stool samples will be collected from each patient to analyse their microbiome and will be linked to treatment response, by examining blood samples and - if available - tumour and organ samples. The investigators hope this work will enable personalisation of patient immunotherapies based on microbiome biomarkers, as well as precisely manipulate a patient's microbiota to optimise their immunotherapy. In addition, participants who have consented to take part in an optional sub-study may be offered a single nasopharyngeal swab for COVID-19 antigen before study entry. The investigators hope that that this identify correlations between the microbiome and COVID-19. Comparison with a limited cohort of healthy household members (up to 360 volunteers) acting as controls will provide additional essential information about the role of the patient-specific microbiome.