[Image by Holger Langmaier from Pixabay]
A study of 1,944 patients published in JAMA found that pharmacogenomic testing helped to minimize drug-gene interactions in patients with major depressive disorder (MDD) but had little to no effect on symptom remission at 24 weeks.
In the randomized trial, 45% of patients who received pharmacogenomic testing had no predicted drug-gene interactions. Of those who received standard of care, 18% had no such interactions.
Patients in the trial were selected from Department of Veterans Affairs (VA) medical centers from July 2017 to February 2021.
“From a VA policy perspective, I don’t think that we would say the study is robust enough that we recommend testing everybody,” said Dr. David Oslin, director of VA’s VISN 4 Mental Illness, Research, Education, and Clinical Center (MIRECC). “The results were not a slam dunk, and in fact, an important outcome of the study is that only about 15% to 20% of the patients had genes that would significantly interfere with the prescribed medication,” Oslin continued in a VA news release. But Oslin reasoned that the data could encourage providers to obtain genetic information to inform the treatment of patients with MDD.
“Future research should explore if there are subgroups of patients who would benefit more from testing,” Oslin concluded.
In theory, validated biomarkers could help inform treatment response, including the choice of alternative antidepressants if an initial therapy proves ineffective. Patients with drug metabolic abnormalities may be less likely to benefit from some antidepressants.
A companion editorial piece published in JAMA concluded that pharmacogenomic testing for next-step antidepressant selection remains a “work in progress.”
Earlier studies published in the Journal of Psychiatric Research and Clinical Psychopharmacology and Neuroscience indicated that pharmacogenomic study might have advantages in terms of effectiveness and tolerability. The former study concluded that pharmacogenetic-informed medication selection “significantly improves outcomes of patients diagnosed with depression or anxiety” in various settings.
There remains a significant unmet need in treating patients with MDD. The NIH estimates that 21.0 million adult Americans have had at least one major depressive episode. Predicting outcomes for individuals with MDD remains challenging, and fewer than 40% of individuals with MDD reach clinical remission after beginning an initial antidepressant therapy.