Identifying Biomarkers for Companion Diagnostics in Immuno-oncology*
Marlon Rebelatto, PhD
Principal Pathologist, MedImmune LLC
The work in the last 30 years in immuno-oncology has clearly demonstrated that the immune system is capable of detecting and destroying cancerous cells. A better understanding of the immunological mechanisms involved in the immune response against tumor antigens has led to the development of effective immunotherapies, which are having a substantial impact on the treatment of some advanced malignancies that were previously untreatable. However, a significant proportion of patients do not respond to monotherapies and combination therapies in development have so far provided only marginal improvements and with additional toxicities. The identification of the right patients for the right therapy continues to be an essential aspect of drug development.
The field of immuno-oncology continues to unveil the complex interactions of multiple cell types and the multitude of soluble factors, cell receptors and ligands, which interact in a coordinated, time dependent and anatomic fashion. This complexity provides a challenge in the identification of unique predictive biomarkers for development of companion diagnostics. However, with greater understanding of biology, scientists may be able to narrow the list of candidate biomarkers that relate to the mechanism of action of a given drug or the biology being targeted. Despite these challenges, recent advances in technology now provide a variety of platforms and matrices where biomarkers can be developed as companion diagnostics.
In this presentation, we describe approaches to identify and implement testing of biomarkers in clinical trials, as potential companion diagnostic tests in predicting response to certain drugs, and also as tests that may guide oncologists and patients in the treatment decision process. We present some technical options from a pathology perspective and discuss some challenges and opportunities in the quest for clinically meaningful diagnostic tests.