UCSF Cardiologist Prof Faults FDA on PMA Supplements

Writing for the Annals of Internal Medicine, Rita F. Redberg, MD, has taken FDA to task for insufficient rigor in its Premarket Approval (PMA) supplement approvals.

Redberg is Professor of Medicine in the Women's Cardiovascular Services Division of Cardiology, at the University of California, San Francisco, and wrote, along with coauthor Sarah Zheng, "Premarket Approval Supplement Pathway: Do We Know What We Are Getting?" which was published online.

PMA supplements are required whenever a change is made to an approved device. The PMA process is required for any modification "affecting the safety and effectiveness of the device for which the applicant has an approved PMA." Redberg says that the process as currently implemented is too lax  Clinical data should be more frequently required as part of the PMA supplement, she says.

Redberg, told Michael O'Riordan, writing for Medscape, that, "Some devices have hundreds of PMA supplements. One of major challenges is that these changes can be iterative, with literally changes on top of changes, so that you have a device that looks very different from the original device."

"I understand the critical importance of trying to get these devices on the market," Redberg continued, "but if there turns out that there is a problem with the new design, these things are not like cars or trucks on the market. They're implanted in people. We can't just get them back."

As an example, Redberg cites the case of Medtronic's Sprint Fidelisdefibrillator lead. These  leads underwent several PMA supplement approved changes to the original design. None of the PMA supplement changes required clinical testing. Still, the final version of the Fidelis lead differed significantly from the design that FDA originally approved. Eventually Fidelis leads had to be recalled because of an increased risk of lead fractures.

In her other writings, Redberg is also a crusader against excessive radiology. Her "We Are Giving Ourselves Cancer" was published in the New York Times Opinion Pages the end of January.

Stephen Levy is a contributor to Qmed and MPMN.