Predicting Response to Immunotherapy for Melanoma With Gut Microbiome and Metabolomics (PRIMM)

This pilot project will assess the gut microbiome with metagenome sequencing before and after starting immunotherapy in stage 3 and 4 melanoma patients. The project will assess the impact of the gut microbiome on treatment response rates and side effects induced by immunotherapy.

200 stage 4 and 250 stage 3 melanoma patients naive to immunotherapy will be recruited from melanoma clinics. Stool samples will be donated pre-treatment and at follow-up visits throughout treatment. An additional sample will also be requested in the event of disease progression or toxicity necessitating treatment delay or discontinuation. An accompanying stool sample questionnaire will be completed at each sampling time point with the optional completion of a 24-hour recall food diary.

Blood samples will also be taken before and after starting immunotherapy treatment, with gastrointestinal, food frequency, quality of life questionnaires administered at baseline. An optional tumour biopsy if safe and accessible, is requested from patients in the stage 4 cohort before and after starting immunotherapy.

Microbiome data from melanoma patients will be compared with the TwinsUK healthy control gut microbiome data on more than 3000 healthy adults. This analysis will help us assess if there are major differences between the microbiome composition in the melanoma cases prior to therapy compared to the control gut microbiome data from TwinsUK.