Boston Scientific (NYSE:BSX) officials changed their mind about an up-coming presentation of study results regarding the company’s Watchman stroke prevention implant, deciding to present the full safety results.
The change of heart came after Wall Street analysts and American College of Cardiology conference organizers voiced concern and surprise at Boston Scientific’s original announcement that it would present just 1 of 3 safety endpoints results at this weekend’s conference in San Francisco.
"This is truly a late-breaking clinical trial presentation," Boston Scientific cardiac rhythm management chief medical officer Dr. Kenneth Stein said in prepared remarks. "The last patient 6-month follow-up occurred in January and the team has been working diligently to complete the preliminary analysis of the data."
Boston Scientific had said in a conference schedule released this week that it would unveil only "the acute procedural safety results of the PREVAIL clinical trial," a decision that some analysts speculated could bode ill for the Watchman device’s safety profile.
"We find this highly unusual given that Prevail is one of the featured late-breaking trials at ACC," Wells Fargo analyst Larry Biegelsen said in a note to investors this week. The hesitation to reveal the full results may indicate that the Watchman device failed to meet the other endpoints, he speculated. "Given the unusual nature of this development, i.e. only 1 of 3 primary endpoints being presented, we would not be surprised to see this decision change by Saturday."
Biegelsen proved correct, as Boston Scientific released a statement late last night declaring its intention to present all 3 primary safety and efficacy endpoints from the PREVAIL clinical trial.
"The acute procedural results were completed 1st, and we announced earlier this week that those results would be presented," Stein said in the prepared statement. "We are pleased to announce that the preliminary analysis of the other 2 endpoints will now be presented as well."
Boston Scientific hopes to use the PREVAIL study in support of its premarket approval application with the FDA. That application will also include data from the Protect AF 4-year outcomes data, the WATCHMAN Pilot study 6-year data, the ASAP study and the CAP registry data update, according to the company.
The Watchman device, which is already available in 30 countries, is introduced via catheter and threaded into the heart to close off the left atrial appendage and capture any blood clots that may form there. The device aims to reduce the risk of stroke and may potentially eliminate the need for long-term use of blood-thinning medications.
Natick, Mass.-based Boston Scientific acquired the Watchman device along with AtriTech for up to $375 million in 2011. Last summer the company closed enrollment in a 2nd trial of the device, with more than 2,000 subjects signing on for the randomized comparison of Watchman with warfarin in high-risk patients with atrial fibrillation. In August the device won expanded CE Mark approval in the European Union for the catheter-based clot-capture system, to patients with atrial fibrillation who can’t be treated with warfarin or new oral anticoagulants.
