Building the Infrastructure to Drive and Support Personalized Medicine
Recent biomedical research breakthroughs, including the sequencing of the human genome and a deeper understanding of the molecular underpinnings of disease, have the potential to transform the treatment of disease and the practice of medicine. One of the most profound changes to medicine is the movement toward tailored therapeutics, or personalized medicine. As defined by the President's Council of Advisors on Science and Technology (PCAST), personalized medicine is the tailoring of medical treatments to the individual characteristics of each patient, and the ability to classify individuals into subpopulations based on their susceptibility to a particular disease or their responses to a specific treatment. Personalized medicine therefore has the potential to optimize targeted delivery and dosing of treatments so patients can receive the most benefit with the least amount of risk, cutting out the difficulties of the current trial-and-error process many patients endure to find the correct drug and dose to treat a condition.
Predicting Adverse Reactions to Drugs
Patients respond differently to medicines, and all medicines present the possibility of side effects. Based on the belief that these differences may be based on genetic factors, FDA has been providing scientific and strategic input to the International Serious Adverse Events Consortium (iSAEC) to identify genetic markers that are useful in predicting the risk of drug-related serious adverse events. The iSAEC's initial studies have successfully identified genetic variants associated with drug-related liver toxicity and serious skin rashes. While the majority of iSAEC's genetic findings have been focused on a specific drug instead of across multiple drugs, a number of cross-drug inherited genes are emerging that may provide important insights into the underlying biology leading to a drug-induced serious adverse event.
Realizing the promise of personalized medicine requires a sustained commitment to advancing our understanding of the structure and function of our genomes, the underlying genetic and environmental bases of human disease, and human genomic variations and the ways in which these variations influence disease or responses to therapy. This research also requires a pathway to translate such findings to real world medical products and practices.
Much of the applied regulatory science for evaluating the strategies and outcomes for personalized medicine - such as standards for whole genome sequencing, fully qualified biomarkers (measurable characteristics in patients), and innovative clinical trial designs and statistics - are still underdeveloped. Additionally, the move toward personalized medicine is resulting in an increasing number of new products that fall within the purview of multiple centers at FDA, creating an additional challenge during the approval process. To address these issues, FDA will continue to take a leadership role on the scientific front and build the infrastructure necessary to support the development of these more personalized targeted therapies, most immediately through investments in regulatory science, clarification of FDA policies, a reorganization of leadership, and engagement of physicians, patients, and their advocacy groups.
Scientific Leadership: Supporting Personalized Medicine through Regulatory Science
Human embryonic stem (ES) cells, which hold great promise for providing innovative treatments for a variety of incurable diseases like Alzheimer's, Parkinson's, and diabetes, have the ability to proliferate for an indefinite period of time and can develop into a variety of cell types. However, the mechanism of differentiation, or how cells change from one type to another, and the factors regulating cell development are not completely understood, meaning ES cells may vary when grown in different conditions or may change forms, potentially developing into cancer cells. To address this challenge, scientists at FDA's Center for Biologics Evaluation and Research (CBER), in collaboration with NIH, the National Institute of Standards and Technology (NIST), and academia, are developing new methods to evaluate stem cells using a variety of advanced analytic methods that compare the cells' characteristics when grown in a dish to how they change when placed in an animal. This approach allows scientists to correlate the measurable characteristics of the cells with a desired result, such as the repair of a blocked blood vessel, or with undesired or toxic effects. The knowledge gained from these studies, including the cells' characteristics and how they change, contribute to the development of safe and effective ES cell-based products being evaluated by CBER for humans and will be used to create advanced tools and processes for evaluating how ES cell-based products planned for humans will perform.
As we continue to expand our understanding of how genomic variations contribute to an individual's disease or response to therapy and gain deeper insights into the mechanisms underlying diseases and disease subtypes, innovative medical product development will increasingly use strategies where diagnostics and drugs are "co-developed" allowing for the diagnostic to guide which patients will be more likely to benefit from the drug and less likely to be at risk for serious side effects.
In order to fully realize the co-development approach, clinical development programs for medical products will require increased investments in regulatory science. Regulatory science, the term used to describe the knowledge, tools, standards, and approaches necessary to assess the safety, efficacy, quality, and performance of FDA-regulated products, will play an important part in addressing the challenges presented by personalized medicine. FDA's regulatory science initiative, as discussed in the Agency's Advancing Regulatory Science for Public Health white paper issued in October 2010 and the recently released Strategic Plan for Regulatory Science, calls for investments in key scientific areas necessary to promote innovation in personalized medicine.
Approaches that use novel clinical trial designs and statistics will be crucial. These novel designs will allow for patient selection strategies that identify those patients who will derive the most benefit from a treatment, balancing the need for methodological rigor with the need for more rapid, targeted answers and smaller study populations. Equally important are improved approaches to identify and qualify the performance and quality metrics of biomarkers to ensure that diagnostic tools can be developed and used to guide the selection of therapies.
FDA will continue to invest in these key scientific areas through direct funding efforts and collaborations with other agencies, such as NIH. FDA will also work to expand its efforts through collaborations with other government agencies and academia, as well as through public-private partnerships with industry scientists as collaborative partners to support these efforts.
Regulatory Infrastructure: Facilitating Personalized Medicine through FDA Policies and Procedures
Because science alone is not enough to translate personalized medicine from microscope to marketplace, FDA is also developing a series of regulatory policies and procedures to support its fruition. The Agency has received feedback about policies related to personalized medicine from industry groups that regard personalized medicine as one of the most promising avenues for new drugs and other innovative medical products.
During discussions about the future of medical devices in relation to personalized medicine, representatives of industry specifically requested that FDA address the issue of companion diagnostics, the tests that are used to determine whether a particular therapy may work for a particular patient. In response, FDA issued the draft guidance entitled In Vitro Companion Diagnostic Devices on July 12, 2011, to communicate to industry how FDA defines these devices and to assist sponsors in understanding the Agency's perspective on them.
The In Vitro Companion Diagnostic Devices guidance addresses several key elements for developing drug/diagnostic products, such as when an in vitro diagnostic test is considered a companion diagnostic and what requirements apply when companion diagnostics are used in clinical trials. It also outlines the steps necessary to obtain FDA approval if a company were to develop a diagnostic that identifies patients with an increased probability of responding to a therapy or an increased risk of adverse reaction to a new or existing therapy, and it specifies the information that must be included in the label of the test and its corresponding therapeutic product. In other words, it seeks to ensure that the tests steering patients toward targeted therapies are accurate and reliable and that the right patients receive the right drug at the right dose, promoting the basic tenets of personalized medicine.
As a follow on to the In Vitro Companion Diagnostic Devices guidance, FDA is also developing a draft guidance outlining strategies for clinical trial design and regulatory considerations for co-developing a novel companion diagnostic and therapy simultaneously, where the approval and subsequent use of the therapy would incorporate a requirement for the diagnostic test. This draft guidance includes recommendations for the strategic use of biomarkers for patient selection and screening, as well as clinical trial designs that allow for ethical patient selection strategies. FDA is also producing an internal plan for how it will review applications using co-development strategies for product development to accompany both guidances and ensure the Agency meets the special needs of these types of products in a timely way.
It is fully anticipated that the pathway to personalized medicine will utilize an individual's full genomic sequence, and rapid developments in ultra high throughput genomic sequencing technologies indicate that the era of the personal genome is fast approaching. In order to effectively utilize these new sequencing technologies for clinical applications, appropriate evaluation tools in the form of standards and criteria are needed to ensure sequencing quality and the accuracy of tests. Though public meetings and direct engagement, FDA is actively seeking input from academia, industry, patients, and other stakeholders on validation methodologies, materials, and bioinformatics approaches needed to address these issues and accelerate and support the introduction of innovative sequencing applications.
Deputy Commissioner for Medical Products
Promoting personalized medicine not only means having the right policies and science in place, it means making sure the FDA medical product centers work together as a team to get safe and effective new treatments to patients as quickly as possible. Since the primary responsibility for diagnostic approvals lies within CDRH while drugs, biologics and cell-based therapies lie in CDER and CBER, coordination between the Centers for applications incorporating diagnostics as a requirement for therapy use will be necessary.
To spearhead efforts for a seamless integration between the Centers as they must increasingly work together to promote highly innovative personalized therapies using the latest science and streamlined processes and procedures, the FDA Commissioner appointed a new Deputy Commissioner for Medical Products to oversee and manage the three medical product development centers. The Deputy Commissioner for Medical Products will be responsible for providing overall leadership for the three medical product centers. This person will also be responsible for other programs, such as combination products, where the Centers must work together to establish cross-center programs.