Boston Scientific (NYSE:BSX) announced that its PROTECTED TAVR clinical trial evaluating its Sentinel system missed its primary endpoint.
Marlborough, Massachusetts-based Boston Scientific designed the Sentinel cerebral protection system to capture and remove embolic debris stemming from transcatheter aortic valve replacement (TAVR). The goal is to extract the debris before it can reach the brain and potentially cause a stroke. Sentinel provides cerebral embolic protection (CEP) during TAVR.
PROTECTED TAVR evaluated periprocedural stroke reduction and neurologic outcomes in patients with aortic stenosis treated with either Sentinel during TAVR or TAVR alone. It did not meet its primary endpoint. Data demonstrated a non-significant trend toward a lower rate of stroke in patients treated with the Sentinel device. The study demonstrated a 21% relative risk reduction in all stroke through 72 hours or time of hospital discharge (2.3% with TAVR and CEP vs. 2.9% with TAVR only).
A secondary analysis demonstrated a statistically significant 60% relative risk reduction in disabling stroke through 72 hours or time of hospital discharge in patients treated with Sentinel. (It was 0.5% with TAVR and CEP vs. 1.3% with TAVR only).
The company presented data at the 34th Transcatheter Cardiovascular Therapeutics (TCT). Researchers are publishing results in the New England Journal of Medicine, according to Boston Scientific.
Still, there are positives to take from Sentinel data
“Data from the PROTECTED TAVR trial provide the physician community with evidence that the device plays an important role in reducing disabling strokes across patient types in those undergoing TAVR,” said Dr. Samir Kapadia, chair of the Robert and Suzanne Tomsich Department of Cardiovascular Medicine, Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute, Cleveland Clinic. “We also found that the rate of vascular complications in this trial was very low, whether or not the device was used, highlighting the safety of this technology in TAVR procedures.”
PROTECTED TAVR enrolled 3,000 patients across more than 50 global sites and all surgical risk levels. Boston Scientific said it is the largest randomized TAVR trial to date. Subgroup analyses demonstrated consistency across patient subgroups that the reduction in disabling stroke using Sentinel.
Clinical trials in the past demonstrated safety and effectiveness for the Sentinel device. It proved to capture and remove cerebral embolic debris in 99% of TAVR cases.
“Considering strokes are unpredictable, can occur regardless of an individual’s clinical background and often take a great toll on a patient’s quality-of-life and financial stability, we believe the data appear to demonstrate a consistent effect from CEP technology across all patient populations in the trial – supporting the use of the SENTINEL device as an effective therapy to reduce the risk of the most debilitating form of stroke for patients undergoing TAVR,” said Dr. Ian Meredith, global CMO, Boston Scientific. “We look forward to additional data on this technology such as from the currently enrolling PROTECT TAVI trial in the United Kingdom, which will similarly evaluate TAVR-related stroke reduction using the SENTINEL device.”
Analyst’s view
BTIG analyst Marie Thibault wrote that, following the data readout for the trial, those at TCT debated the impact of the disabling stroke results. According to Thibault, some said the findings shouldn’t be ignored while others saw it as a secondary endpoint in a “negative trial.”
When polled publicly, the physician panel discussing results voted 7 to 1 to use Sentinel, she said.
“For now, we think the ambiguity of the trial isn’t likely to change clinical practice, with believers of the device continuing to use it, and those yet to adopt staying on the sidelines,” Thibault wrote. “Although PROTECTED TAVR missed its primary endpoint, we believe BSX can drive growth with multiple new products and expanding market opportunities. Reiterate Buy.”