In mid February we covered the Stryker’s Wingspan Neurovascular Stent situation quite extensively here. At the time, pressure was being exerted by patient groups for FDA to withdraw its Humanitarian Device Exemption Approval. Most notably, “Public Citizen”, fuelled by poor clinical results in studies on the device, called its ongoing availability a “reckless disregard for public safety”. This was given more weight because it was uttered by a former FDA surveillance officer and CDRH director.
Fast forward to March 21st, and with FDA’s formal panel review due to take place in two days time, the agency has released an executive summary of the case, entitled “Current Knowledge of the Safety and effectiveness of the Wingspan Stent System with Gateway PTA Balloon Catheter for the Treatment of Intracranial Arterial Stenosis” and available here.
The FDA report is frankly not a good read if you’re Stryker, although it’s unsurprising as the poor clinical results have been widely reported elsewhere. Most notably, the pivotal post-approval study entitled “Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis” (SAMMPRIS), which involved subjects randomised into two groups of high risk subjects with symptomatic intracranial arterial stenosis; The groups were Angioplasty and stenting (using the Wingspan System) combined with aggressive medical management (AMM) and aggressive AMM alone.
After randomization of 451 subjects, on April 5, 2011 enrollment in the SAMMPRIS trial was stopped, based on the finding that 14.7% of subjects treated with the Wingspan System experienced a stroke or died within the first 30 days after enrollment compared with 5.8% of patients treated with aggressive medical management alone (a clinically and statistically significant difference).
Obviously the SAMMPRIS study, despite being the only randomised controlled study on this specific product, is only one consideration for FDA, the report including many other data sets. So it’s a case of watching this space to see what FDA concludes. Of equal significance however is the position in Europe, where the device is CE mark approved and in clinical use. If FDA concludes risks outweigh benefits, presumably EU regulators or indeed the Stryker itself will need to confront the situation and consider the product’s continued availability.