By Joseph Walker
WASHINGTON-- Medtronic Inc., undeterred by a surprising and
definitive clinical-trial failure, said it will continue to develop
its medical device for high blood pressure in hopes of winning U.S.
regulatory approval.
The company shocked doctors and industry rivals in January when
it said that its device, used to singe nerves in the kidneys with
low levels of radio-frequency energy, had failed in a large
clinical trial to lower patients' blood pressure more effectively
than a placebo, or sham, procedure.
Observers said the data from the study, which had been meant to
support U.S. Food and Drug Administration approval, left the
company with little room for optimism in the near term.
Prior studies had shown the device, called Symplicity, produced
dramatic improvements in the high blood pressure, or hypertension,
of patients who hadn't benefited from prescription drugs. Prominent
physicians and medical societies heralded a potential miracle
treatment for hypertension, a significant risk factor in heart
attacks and strokes.
On Saturday, detailed results of the Medtronic study were
presented for the first time at the annual meeting of the American
College of Cardiology and were simultaneously published in the New
England Journal of Medicine.
The results showed that both study groups--patients who
underwent so-called renal-denervation procedures with Medtronic's
device and the placebo patients--experienced drops in blood
pressure, with slightly greater reductions for those getting the
real procedure, though the difference wasn't statistically
significant. An editorial accompanying the study manuscript in the
New England Journal of Medicine described the advantage as
"paltry," and said the study had brought "the renal-denervation
train to a grinding halt."
Nina Goodheart, vice president of renal denervation at
Medtronic, said "signals" in the data suggest the treatment might
benefit certain patients, depending on what drugs they were taking.
It is also possible that the procedure wasn't performed correctly
or completely during the study, Ms. Goodheart said, citing what she
said were small but encouraging pieces of data that weren't
included in the New England Journal of Medicine manuscript. The
company is in discussions with the FDA about how to move forward
with a new clinical trial, Ms. Goodheart said.
"We've seen enough positive clinical signals that this therapy
warrants further investigation," she said in interview. "Are we
willing to invest in another clinical trial? Yes."
Ms. Goodheart's tone contrasted starkly with that of Medtronic
executives in January, when the company first said the study had
failed, and in February, when it wrote off $236 million related to
its renal-denervation program--acquired through an $800 million
acquisition in 2010. Medtronic has done significant data analysis
in the months since, Ms. Goodheart said, pointing out that there is
a large unmet medical need, and market opportunity, to treat
certain hypertensive patients.
Several other companies, including Boston Scientific Corp. and
St. Jude Medical Inc., also are developing renal-denervation
devices for use in the U.S., and eagerly had been awaiting data
from Medtronic's study.
Renal-denervation devices, including Medtronic's product, have
been approved in Europe for several years, and some 10,000
procedures are estimated to have been performed around the world.
The negative results from Medtronic's study are likely to give many
doctors pause in offering the procedure in countries where it is
approved.
"I'd be cautious about offering the procedure to patients in the
face of a negative large clinical trial," said Deepak Bhatt, a
cardiologist at Harvard Medical School and an investigator in the
study.
The study data released Saturday don't show a statistically
significant advantage for treatment with Medtronic's device
compared with the sham procedure, even when specific patient
characteristics such as race, gender or age are taken into account.
A placebo effect, in which patients' belief that they have received
an effective therapy positively influences physiological response,
was present in the study, said Dr. Bhatt, a co-author of the New
England Journal of Medicine paper. Still, he said that development
renal-denervation technology as a whole shouldn't be abandoned, and
that subsequent trials should be performed to see whether changes
in patient selection or procedural training would produce different
results.
Other physicians said the study highlighted the need for
medical-device trials to include sham control groups to ascertain
whether patients are receiving a therapeutic effect. Sham studies
historically have been uncommon in the field of medical devices and
surgery.
"The sobering results of the Symplicity trial cut through the
fog of hope and hype in renal denervation," said Sanjay Kaul, a
cardiologist at Cedars-Sinai Medical Center in Los Angeles.
Write to Joseph Walker at joseph.walker@wsj.com
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