By Independent Staff Writer
In
August 2005, the FDA approved an application for the DePuy ASRTM XL
Acetabular System, allowing DePuy to market the new, metal-on-metal
system to patients needing total hip replacement surgery. To those
patients, this FDA approval meant one thing: the DePuy ASRTM XL
Acetabular System was safe.
But, in
its first five years, the ASR System failed at such catastrophic rates
that DePuy issued a voluntary recall in August 2010, affecting tens of
thousands of patients who have to undergo revision surgery.
How
could this happen? Isn't it the FDA's job to verify and ensure the
safety and effectiveness of medical devices sold in the United States?
The
admitted failure rate of the ASR XL Acetabular System is 13%-meaning,
this is the number acknowledged by DePuy. Mounting evidence suggests
that the failure rate is higher than that, especially if one doesn't
limit the definition of "failure" to DePuy's narrow view.
The DePuy ASRTM XL Acetabular System
gained FDA approval through the 510(k) process, which bypasses clinical
testing altogether if the product is "sufficiently equivalent" to other
products already on the market.
Which
means the ASR System was never clinically tested before it was sold to
patients, and it underwent only the most rudimentary safety tests. DePuy
only had to state that their new product raised no new safety concerns.
The FDA - evidently - took them at their word.
Congress and consumer advocacy groups have been calling for of the 510(k) process,in part due to similar recalls from DePuy and other medical device companies. As of August 2010, the FDA has issued two preliminary reports that recommend sweeping changes.
The
reports indicate that consumer advocacy groups had strong concerns
about "predicate quality"-that is, the quality of the already approved
devices to which DePuy claimed their new product was substantially equivalent.
Per
the current 510(k) requirements, a company can claim its product is
substantially equivalent to a product that never underwent clinical
testing, was made before 1976, or had been recalled. That's right: the
ASR System got through on a kind of loophole, and now another
manufacturer can come along and claim their product is substantially
equivalent to it-and be approved.
Had this negligence been rectified years ago, the ASRTM XL Acetabular System might never have gone to market.
The
preliminary reports also recommend getting rid of the rule that allows a
company to base its substantial equivalence claims on more than one
product. This change would almost surely have invalidated DePuy's ASRTM
XL Acetabular System application, because DePuy based its substantial equivalence claim on no fewer than three devices.
Perhaps
most important, the reports call for an improvement in the quality of
the clinical data submitted to support substantial equivalence. How has
the FDA justified making an educated decision about a new product's
safety and effectiveness without strong clinical data?
If DePuy had been mandated to conduct clinical studies before the ASR System was sent to market, the terrible fact of a one-in-eight
revision rate might've been avoided. Tens of thousands of patients
might've been spared the painful truth that will need to undergo a
second hip implant just a few years after receiving the first.
Critics have long argued that companies use the 510(k) process is a loophole
that allows companies to get around the more arduous premarket approval
process otherwise required by the FDA. While it's true that the 510(k)
process saves companies a lot of time and money, the cost is merely
passed on to the patients, who pay with their money, pain, and quality
of life.
We can only hope that the
proposed reforms to the current process take effect soon and prevent
more tragedy from prematurely approved devices like the DePuy ASRTM XL
Acetabular System.
