Marlborough, Mass.-based Boston Scientific Corp. is heralding results from a study of its Luminize radiofrequency (RF) balloon catheter for isolation of pulmonary veins (PV) when treating patients with atrial fibrillation.

The prospective, nonrandomized, multicenter study, known as AF-FICIENT I, enrolled 100 patients with symptoms of paroxysmal – or intermittent – atrial fibrillation. Confirmation of PV isolation was completed with the RF balloon sensing electrodes, a circular mapping catheter, or both. Results were presented during a late-breaking clinical trial session at EHRA 2019, the annual congress of the European Heart Rhythm Association in Lisbon, Portugal.

Currently, patients with arrhythmias receive anti-arrhythmic drugs and cardiac ablation. With this single-shot catheter, RF energy aims to isolate the areas of the heart muscle responsible for the abnormal heart rhythm. The catheter also features built-in digital cameras for visual guidance, sensing electrodes on the balloon to assess real-time vein isolation and customizable ablation electrodes with the ability to deliver tailored levels of energy around the circumference of the balloon.

"By providing real-time visualization both before and during ablation and individualized control of electrode energy levels, this technology may allow physicians to swiftly and accurately isolate veins and decrease procedure times," said Ken Stein, senior VP and CMO, rhythm management and global health policy, Boston Scientific.

Results from AF-FICIENT I

The global AF-FICIENT I study examined acute procedural success and safety for catheter in two phases, the first of which examined the original design of the device. The second included changes to bolster the maneuverability and add dedicated pacing and sensing electrodes. Data from the first phase showed PV isolation was achieved in 88.9 percent of veins. During the second phase, with the enhanced steering capability and electrodes activated, PV isolation increased to 99.4 percent of veins. In addition, there were no device-related serious adverse events in either phase 30 days after the completion of the procedures.

The company also said that the median time the balloon was in the left atrium – known as balloon dwell time – decreased from 92 minutes in phase one to 29 minutes in the second phase, bringing the total procedure time down to a median 71 minutes.

"For a product studied this early in its development cycle, the safety and efficacy data and procedural times were all very encouraging," Stein told BioWorld MedTech when asked whether there was anything in the study results that surprised him.

Apama buy

Boston Scientific picked up the product as a result of its purchase of Apama Medical Inc. The company reported that deal, worth $175 million in cash up front, in October 2017. (See BioWorld MedTech, Oct. 4, 2017.) Boston Scientific could hand over up to an additional $125 million in contingent payments over the period of 2018-2020, based on achievements of clinical and regulatory milestones.

"We know that a competitor has an RF balloon in clinical trials, but it lacks the endoscopic visualization and dedicated distal sensing electrodes provided by the Luminize RF balloon catheter," Stein replied when asked whether Boston Scientific was aware of other companies working on something similar.

Moving forward, the company expects to submit the results to regulators and hopes to disseminate them further during presentations and in publications, Stein noted. He added that the company hopes to receive the CE mark in the second half of 2019. "Discussions are underway with the FDA," he noted. "We anticipate starting our U.S. IDE trial in the second half of this year."

Other deals

Boston Scientific has been busy over the last year or so in terms of making deals. In addition to Apama in the EP space, the company agreed to acquire the rest of Cryterion Medical Inc. that it did not own for $202 million in up-front cash last summer. (See BioWorld MedTech, July 6, 2018.) The attraction of Cryterion, of Carlsbad, Calif., was its single-shot cryoablation platform for the treatment of atrial fibrillation. Marlborough, Mass.-based Boston Scientific noted that it has invested in Cryterion since its 2016 inception.

During Boston Scientific's fourth-quarter earnings call last month, CEO Michael Mahoney said that within electrophysiology (EP), the company saw sales grow 8 percent. "We continue to enhance our catheter pipeline globally, and importantly, our two single-shot platforms, Cryterion and Apama, are on track to launch in Europe by the end of this year as well as begin enrollment in their IDEs for U.S. approval."

The company has looked to grow beyond EP, making a host of deals. David Lewis of Morgan Stanley asked about the company's ability to integrate multiple transactions as well as the pace of additional M&A this year.

Mahoney noted that Apama was on track, adding that he had no concerns about continuing to integrate the company's deals." We will see the pace of M&A slow for us in '19. As we stated before, we do have capacity to do some tuck-in acquisitions, but you won't see the volume of activity in '19 that we had in '18," he added. (See BioWorld MedTech, Feb. 11, 2019.)

CABANA shows issues?

Even with the positive results, there are some questions about catheter ablation. Findings from two studies that appeared March 15, 2019, in the Journal of the American Medical Association determined that the procedure appears no more effective than drug therapies in preventing strokes, deaths and other complications in patients with atrial fibrillation. With that said, those who get the procedure experience much greater symptom relief and long-term improvements in the quality of life.

Specifically, the papers examined outcomes of the Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial, which was a randomized study that compared drug therapies for atrial fibrillation to ablation.

From November 2009 to April 2016, CABANA enrolled more than 2,200 patients at 126 sites. Roughly half the patients were assigned to the ablation procedure. Those who received drug therapy were allowed to choose to undergo ablation if their symptoms could not be controlled. An estimated 27 percent of those on the drug therapy arm ended up also receiving ablation.

"While data from the trial did not show that ablation was superior to drug therapy in reducing rates of deaths and strokes, it showed reduced recurrence of atrial fibrillation, as well as reductions in hospitalizations," said Yves Rosenberg, the program officer for the study and chief of NIH's National Heart, Lung, and Blood Institute's Atherothrombosis and Coronary Artery Disease Branch.