2017 Review: Precision Medicine - From Traditional to Tailored Treatment
With continued advances in technology, and the increasing focus on individualized therapy, the field of precision medicine has once again been a major focus in 2017. Following on from the launches of the Precision Medicine Initiative and the All of Us Research Program in the US in 2016, and many other initiatives around the globe in the past 2 years, this rapidly growing field has become a major research investment sector.
Technological Advances Allow Personalized Treatment Plans
Precision medicine refers to the tailoring of medical treatment to the individual characteristics of each patient, identifying which approaches will be the most effective for which patients, based on genetic, environmental, and lifestyle factors.
Personalization of therapy is not a novel concept. Blood typing, for example, has been used for decades to guide blood transfusions. However, informatics and information breakthroughs in genomics such as full-genome sequencing and next-generation sequencing (NGS) technologies, combined with other omics signatures (proteomic and metabolomics), has allowed patient stratification to make therapy personalized.
Biomarkers and Companion Diagnostics are the Key to Successful Precision Medicine
To realize precision medicine, two components are essential:
- a targeted therapy
- a companion test to identify a biomarker.
Companion diagnostics are used to identify the genes, proteins, and other signatures needed to implement the use of a targeted therapy. This allows the stratification of patients within a given illness – selecting only those who are likely to benefit from a therapy to then receive that targeted agent.
Therefore, biomarkers that can predict treatment response are critical for the success of precision therapy for cancer patients, and in oncology drug development. Moreover, during the course of the disease, companion diagnostics may also help provide additional information on the effectiveness of treatment or the disease progression.
2017 Brought Historic FDA Approvals to Drive Forward Precision Medicine
Innovation in this domain was highly visible during 2017. First in May, for the first time in their history, the U.S. Food and Drug Administration approved a cancer treatment based on a biomarker regardless of the origin of disease.
The agency granted an accelerated approval to Keytruda® (pembrolizumab, Merck) for the treatment of adults and children with unresectable solid tumors who have specific genetic biomarkers, known as microsatellite instability-high (MSI-H) and DNA mismatch repair (dMMR), and where tumors have progressed following prior therapy or there are no satisfactory treatment alternatives.
A couple of months later, the first NGS oncology panel test for multiple companion diagnostic indications was FDA approved, marking an important step forward in advancing precision medicine by ensuring the best pairing between patients and drugs.
Liquid Biopsies Advanced Clinical Oncology
Today, tumor biopsy is the main way physicians diagnose most types of cancer, but biopsies can also be used to make treatment decisions as illustrated before.
However, such a sampling method may be inadequate for the comprehensive characterization of a patient’s tumor, as it has been demonstrated that tumors are highly heterogeneous and that genetic diversity can also alter over time. Furthermore, depending on the location of the tumor and the patient’s general health, surgical biopsy procedures may not always be feasible.
However, with the continued development of sensitive techniques, the analysis of circulating tumor cells (CTCs) and cell-free circulating nucleic acids (in particular, circulating tumor DNA (ctDNA) and exosomes) in liquid biopsy has also been intensively investigated this year.
Liquid biopsies offer the opportunity to temporally measure tumor burden, and also the genotype and phenotype of the cancer over time, to detect early evidence of resistance or disease recurrence.
2018 – The Precision Medicine Era Continues
In the era of precision medicine, the implementation of NGS technologies, companion tests, and liquid biopsies offers a great opportunity to increase the number of therapeutic opportunities for every single patient, improving cancer patient care over the years to come.