How to identify the optimal drug?
“The million-dollar question is how we identify the best drug for each individual patient,” Dr. Sundström said. “This study has opened Pandora’s box. We now need to figure out how to go forward and how we tailor treatment in each patient.”
In the study, the researchers suggest that personalizing therapy could be achieved either by identifying the phenotypic characteristics that are associated with enhanced response to one treatment vs. another or by directly measuring the individual’s responses to a series of treatments to ascertain which is most effective.
Addressing the first scenario, Dr. Sundström explained: “We can analyze the characteristics of patients who did best on each drug. There are many variables we can look at here such as age, diet, baseline blood pressure, exercise levels, smoking status, race, body weight, salt intake, and findings from genetic tests. We are going to try to look into these to see if we can find any predictors of response to various different drugs.”
For the second strategy, he suggested that patients starting pharmacologic therapy could try a few different treatments. “For example, we could give patients two different drugs and ask them to alternate treatment periods with each of them and measure their blood pressure with a home monitoring kit and record adverse effects.”
Nonadherence “is such a big problem with antihypertensives,” he added. “This approach may allow patients to be more empowered when choosing the right treatment, which should help adherence in the longer term.”
‘Proof-of-principle’
Commenting on the study in an accompanying editorial, Robert M. Carey, MD, University of Virginia Health System, Charlottesville, wrote: “At this stage, the findings are more theoretical than immediately practical for the implementation of personalized antihypertensive drug therapy, but the study does provide proof-of-principle and the authors suggest a few scenarios in which a personalized approach could be used in the future.”
He said the practical ramifications of personally targeted therapy remain unclear, given that determination of an individual’s response to a series of short test treatments before selecting long-term therapy may be considered too cumbersome, and currently few phenotypic markers are currently available that would be likely to accurately predict the individual response to a particular therapy.
Dr. Carey concluded that the results of this study “encourage the further pursuit of larger randomized trials using similar repeated crossover designs to validate this concept and eventually in trials with longer follow-up data to determine whether there is improvement in long-term clinical outcomes compared with current strategies.”
He added that the results support the possibility that personalized medical treatment of hypertension “may ultimately supplement or even supplant the current method of antihypertensive drug decision-making in the future.”
This study was supported by the Swedish Research Council; Kjell and Märta Beijer Foundation; and Anders Wiklöf. Dr. Sundström reported owning stock in Symptoms Europe AB and Anagram Kommunikation AB. Coauthor Emil Hagström, MD, PhD, reported receiving grants from Pfizer and Amgen and personal fees from Amgen, Novo Nordisk, Bayer, AstraZeneca, Amarin, and Novartis. Coauthor Ollie Östlund, PhD, reported fees from Uppsala University paid to his institution, Uppsala Clinical Research Center, for its participation in the PHYSIC trial during the conduct of the study. Dr. Carey reports no relevant financial relationships.
A version of this article first appeared on Medscape.com.