The future of renal denervation in treatment of hypertension is shaky at best, according to 1 of the principal investigators involved with Medtronic’s disappointing clinical trial.
Despite continued optimism from some of medtech’s biggest players, the fact that renal denervation failed in Medtronic’s highly anticipated Symplicity HTN-3 clinical trial to meet its efficacy endpoint may signal the end of the technology, the investigator told Leerink Partners analyst Danielle Antalffy, citing an unnamed co-principal investigator in the trial.
"This physician believes RDN in hypertension is highly unlikely given his view that the trial’s failure was likely predicated on the approach vs. the device," Antalffy wrote in a note to investors. "If this physician’s perspectives prove out, this call does not bode well for the prospects of RDN to treat hypertension – removing what many viewed to be an exciting major new cardiology market."
Medtronic hasn’t yet released the full data from the study, but announced last week that the results suggest that renal denervation with Medtronic’s 1st-generation Symplicity system is safe but apparently ineffective when compared to a sham treatment.
Rival renal denervation players Boston Scientific (NYSE:BSX) and St. Jude Medical (NYSE:STJ) both said this week that they’re not willing to dump their development efforts just yet, speculating that the technology used in Medtronic’s trial is substantially different from either Boston Scientific’s Vessix or St. Jude’s Enlightn.
"It may be that the trial was done with a technology that was too early-stage – that’s speculative on my part, but that’s among the list of questions that we have," St. Jude CEO Daniel Starks said. "Was the technology effective or was it that the technology was really too hard to use effectively in an expanded environment?"
Boston Scientific CEO Michael Mahoney made similar remarks, citing clinical data from previous clinical trials that have reported significant results with renal denervation.
"We think there are a number of differentiated features with our Vessix platform versus the competitor who failed on their efficacy trial – the fact that it’s a balloon-expandable device, it has a multi-point capability where the electrodes will turn on and turn off if they’re out of position," Mahoney said. "So we think there are ease-of-use benefits, there’s clearly a speed benefit, so we think it’s a better platform."
The investigator cited by Antalffy wasn’t as optimistic, crediting Medtronic’s clinical flop to the renal denervation treatment approach rather than to any particular technology. Competing devices "aren’t substantially different" from Medtronic’s Symplicity, according to the researcher, and the trial failure will likely curb some of the market’s enthusiasm for renal denervation. Drs. George Bakris of the University of Chicago Medical Center and Deepak Bhatt of the VA Boston Healthcare System are listed as co-principal investigators in the trial.
Medtronic’s rival device makers have chosen not to rule decisively 1 way or the other, but Mahoney said this week that Boston Scientific will wait to see Medtronic’s full data before having further discussions with the FDA on how to proceed with its own trial.
"We want to consider the facts of that miss," Mahoney told Bloomberg. "We would be crazy not to take a pause and learn about the findings of that trial and adjust our plans accordingly."
St. Jude had already stopped short on its Enlightn clinical trial, announcing in December that the company would halt the Enlightn IV clinical trial, just a few months after it began. The study was slated to assess nearly 600 patients, but it was halted over concerns that growing momentum for Medtronic’s Symplicity device would hinder enrollment.
UPDATED Jan. 17, 2014