MedicalResearch.com Interview with: Dr Ashray Gunjur MBBS (Hons), B. Med Sci, MPHTM FRACP Clinical Research Training Fellow Melbourne, Australia   MedicalResearch.com: What is the background for this study? Response: As background, the last ~5 years have seen a surge of interest in the relationship between gut microbiota and cancer response to immune checkpoint blockade (ICB). We know that though a fraction of many different cancer types will respond to these therapies, it is currently very hard to predict who that will be- so ‘microbiome’ based biomarkers to select patients, or even strategies to change a patient’s microbiome to enhance their chance of responding, are very attractive. A key challenge, however, has been a lack of consistency in the microbes associated with response or non-response across different studies from different regions. While geographic, methodological, and technical variation likely contribute to this, most studies examined the gut microbiome at a genus- or species- taxonomic rank level, while we know there is significant intra-species (strain-level) diversity. As such, one of our key research questions was whether we could improve the reproducibility of microbial ‘signatures’ of response across cohorts using higher resolution approaches- with our hypothesis being that strain-resolution signatures would outperform species- or lower resolution signatures. We obtained our signature by analysing baseline faecal samples from the CA209-538 clinical trial, a wonderful investigator-initiated study sponsored by the Olivia Newton-John Cancer Research Institute (Melbourne, Australia). I was fortunate enough to work on this trial as a clinical investigator while training to be a medical oncologist. (more…)