With the development of less expensive, advanced technologies for sequencing DNA and locating gene mutations and polymorphisms relevant to drug response, there has been greater incorporation of precision medicine protocols into clinical trials.
However, the rise in utilisation of personalised approaches has not resulted in a significant increase in the development of effective therapies. It is likely that important pieces of the puzzle underlying our understanding of human disease have yet to be discovered.
Current research indicates that the human genome is not the only factor impacting disease diagnosis, prognosis, and response to drug treatment. Increased understanding of metabolic pathways and resulting metabolites has uncovered major roles in disease and these are now being explored further in the development of personalised therapies across various indications.
In addition, a third major player involved in disease is the human microbiome, a complement of bacteria that reside either normally or as a result of certain pathologies or imbalances within the body. Recent research into the human microbiome is starting to uncover evidence that bacteria normally resident to the human body play a major role in determining the pathogenesis of disease, as well as in drug response. These can be utilised by drug developers in tailoring specific, more efficacious therapies.
The involvement of microorganisms in infectious diseases, cancer, central nervous system disorders, and metabolic disorders, suggests that cross-therapeutic approaches in developing therapies may meet higher success than the focus on specific diseases.
The traditional paradigm of approving drugs for a specific disease is starting to change. The recent US Food and Drug Administration (FDA) approval in May of the immuno-oncology checkpoint modulator Keytruda for any patient with Microsatellite Instability-High (MSI-H) or mismatch repair deficient, unresectable, or metastatic solid tumours is one of the examples.
Recent research has shown that the human complement of bacteria in various locations throughout the body falls into different subtypes indicating that particular microbiome subtypes may be correlated with development of certain diseases and play important roles in drug efficacy and safety in these populations.
The future of drug development may include fewer approvals restricted to specific disease indications, and more approvals based on broader criteria such as microbiome subtypes, possibly ushering in a new era of the blockbuster drug, ironically borne of a personalised medicine approach.