Why consider Immune Checkpoint inhibitor Biomarkers, before considering Immunotherapy a mode for treatment
Immunotherapy as a cancer therapy is approved and being implicated for patient treatment, since ipilimumab break into the treatment landscape in 2011. After which tremendous advancement was made in the field of immunotherapy, and in 2016 it is named as American Society of Clinical Oncology’s top cancer therapy (Dizon DS, Krilov L, 2016).
Although the advancement in the field, it is important and necessary to optimize appropriate selection of patients for immunotherapy, to rule out the unnecessary toxicity and health care costs, and truly identify predictive, and not specific prognostics, and responsive biomarkers. Identifying responsive biomarkers is necessary to illuminate the actionable mechanism of novel immunotherapeutic approaches, and potentially identify patients for single agents versus combinational strategies to treat cancer.
What are Biomarkers?
Biomarkers are naturally occurring genes or molecules that are characterized for a particular pathological or physiological process, disease, etc. It refers to a broad secondary category of medical symptoms – that is, clinical indications of medical state observed physically in patient – that can be measured accurately and reproducibly. That indicates the normal and abnormal condition of a disease. It enables to monitor the body’s response to a specific treatment for a disease. Biomarkers included in immunotherapy landscape are (Spencer et al., 2016) :
– Soluble factors such as serum proteins
– Host genomic factors
– Tumour-specific factors such as receptor expression patterns & components of the
microenvironment
The immunotherapy biomarkers are PD-L1 expression; tumour mutation burden; microsatellite instability (MSI); DNA mismatch repair deficient (dMMR).
By channelling the body’s immune system to encounter and destroy tumour cells, biomarkers for immune checkpoint inhibitors are rapidly advancing in field of precision medicine. Hence to rule out the treatment toxicity and cost effective of Immunotherapy, comprehensive genomic and proteomic profiling with Genetic Cancer Test could be beneficial in decision making for Immunotherapy considering the immune checkpoint inhibitors.
Genetic Cancer Test also provides you the analysis of microsatellite instability (MSI) testing, which is beneficial to rule out the tumor sensitivity against immunotherapy, as high MSI is associated to an increased neoantigen (newly formed antigens) burden that makes tumour sensitive to immunotherapy.
Along with which Tumour Mutational Burden (TMB), is also analysed. As high TMB in tumours are considered to protect neoantigens and enable respond to immune checkpoint inhibitors (Rizvi et al.,2015) .
