NEW YORK (GenomeWeb News) — The US Food and Drug Administration “might not” pursue genetic label changes “as aggressively as it had in the past,” and instead hopes to focus more on how biomarkers affect drug safety and efficacy, according to a senior FDA official.
“Perhaps we should focus less on what is already out there — maybe label changes aren't the way we change medical practice — and do everything we can to understand as much as possible about biomarkers that can identify who the drug will benefit … and what is the best dose,” Felix Frueh, associate director of genomics at the FDA, told GenomeWeb News recently.
“These efforts will really change the way drugs will be reviewed and approved in the future,” he added.
Recently, for instance, a majority of an FDA advisory panel said the agency should update the label for the breast cancer drug tamoxifen to include information about CYP2D6 genotype testing, but the panelists have not reached a consensus on certain details of the issue.
In addition, the agency has been mulling whether to change the label on the ubiquitous anticoagulant warfarin to suggest that physicians use a test that interrogates the CYP2C9 and VKORC1 genes before prescribing the drug.
Previously the agency has relied on genotypic data to change the label for the acute lymphatic leukemia drug 6-mercaptopurine and Pfizer’s colorectal cancer agent Camptosar. Those changes recommend dosing changes based on those genotypic data.
Some in industry believe these kinds of label changes would help physicians adopt molecular diagnostics and open the door for new tests and additional label changes.
“One thing that we have realized in  with the label updates have been extremely difficult, to say the least. They have been difficult from two perspectives: The external perspective, wherein even if we updated the label, the uptake in clinical practice has been extremely slow.”
Citing 6-MP and Camptosar, Frueh said "if you look at how these label changes affected clinical practice, it’s almost non-existent.”
He also said the process of changing labels “has told us something about the educational needs and the expectations that the medical officers at the FDA put on genomics are sometimes not realistic because they maybe don’t always understand what genomics does.”