by Phyllis Hanlon, Contributing Writer
The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) and Cardiovascular Medical Research and Education Fund (CMREF) co-sponsored a workshop to look at better ways to treat pulmonary vascular disease (PVD) through precision medicine. Precision medicine, which is sometimes referred to as personalized medicine, is a developing medical model that seeks to customize treatments and medical decisions tailored to the individual patient based on factors such as genetics, environment and lifestyle.
The workshop was prompted by the launch of the “Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics” (PVDOMICS) program. Pulmonary hypertension (PH) treating clinicians and scientists joined the Pulmonary Hypertension Association (PHA) in taking part in this workshop. Highlights of the discussion were published in the June 2017 issue of the American Journal of Respiratory Critical Care Medicine.
A broad cross-section of researchers and experts in heart and lung health took part in the discussion, noting that PVD presents with different symptoms in different patients. There is no “one size fits all” approach when it comes to treatment. The workshop followed the lead of the PVDOMICS program, which studies some of the differences — including newly discovered similarities and genetic differences across different types of PH, how cells turn on and off genes, and how cells use energy, to name a few factors — that can contribute to PAH and PVD. The ultimate goal is to learn information that will lead to new types of treatments and possibly prevention strategies for PH.
Since 1995, 14 medications have been approved in the United States for use in adults with PAH. These drugs have not had the largest impact possible for several reasons. The authors of this paper report that professional groups have not agreed on a specific definition of PVD and that researchers have also failed to establish appropriate goals for clinical trials. Limited understanding of how the currently available treatments work in humans has also hampered efforts to find the best treatment options for individual patients. The authors referred to the Precision Medicine Initiative, which asserts that the right treatment relies on good understanding of the fundamental way disease (in this case, PVD) develops and that finding biological measures that can help accurately classify the disease will lead to more specific and more successful treatment. The authors pointed out that this approach is already used, to some degree, in treating certain sub-types of WHO Group 1 PH (PAH, pulmonary arterial hypertension).
The workshop also determined that currently available data from clinical trials, if examined more closely, could provide some important new information on the effects of some drugs. This existing data can be analyzed by race, gender, effectiveness of treatment and adverse effects. Additionally, if researchers built in certain common elements when designing different studies, more useful data would be available.
Technology can also enhance understanding of PVD, according to the authors. Scientists are able to use algorithms or formulas that automatically find patterns that can be used to predict the response to treatment. This type of “machine learning” could enhance the ability to create targeted therapies and help researchers better identify specific types of PVD.
In trials to date, different goals have been established. These goals include changes in results of the six minute walk distance (6MWD) test, the time it takes a patient to become hospitalized or die from complications associated with the illness, progression of the disease and a decline in functioning. While these goals hold some merit, they are not necessarily helpful for determining a personalized treatment approach, according to the authors. Patients would prefer that a drug’s effectiveness be measured by how it impacts symptoms, ability to exercise and quality of life. Researchers should consider how a person feels and how able they are to perform everyday activities under a treatment plan.
The workshop discussion also examined some factors, which are often overlooked, that should be considered before beginning a treatment regimen. These factors include how a drug affects a patient’s blood vessel cells and/or tissues and the progression of the disease. Clinicians should also evaluate right ventricular and pulmonary vascular function and assess biomarkers (i.e., substances that tell if disease, infection or some negative effect from environmental exposure is present) before prescribing a drug.
The authors pointed out that there are a couple of challenges to successfully implementing these recommendations. First, any attempts to use a precision medicine approach must comply with regulatory guidelines for safety when prescribing drugs for humans. Also, there may be challenges for researchers and the pharmaceutical industry in researching drugs to treat patients with PVD due to the potentially large financial investment involved in treatment approval for what could potentially be a more constrained study group. The average cost of developing a new drug between 2000 and 2010 was “a staggering $2.6 billion.” Pharmaceutical companies are looking for more efficient and less costly ways of finding new treatments. The participants in this workshop agreed that a national database that coordinates all data from funded programs should be available online so a wide range of individuals can access it. Also, they suggested that a task force be assembled to develop protocols (i.e., rules) for clinical trials that use precision medicine principles. This task force should also issue new goals for trials that are well defined and clinically meaningful.
Each PH patient is different. It is essential that you talk to your own doctor about what treatment options are best for you. For more information on finding a doctor or an accredited care center, visit https://www.phassociation.org/PHCareCenters/Patients.