Earlier this year we offered fairly extensive coverage of Stryker’s Wingspan Neurovascular Stent which, it seemed, was posing the FDA something of a conundrum due to worse than anticipated clinical study results, while the product was effectively already on the market, albeit under a Humanitarian Device Exemption.
So what would FDA do? Now we know as it makes public its demand that the product should only be used for a very narrowly defined patient group, namely people at serious risk of life-threatening stroke with limited alternative treatment options.
Patient groups were calling for the withdrawal of Stryker’s Wingspan stent as early as February this year as the results of a pivotal study suggested the outcome, when using the device as an addition to conventional aggressive management methods in high risk patients, was significantly worse than aggressive management alone. At 30 days, mortality in the treatment group was 14.7% vs 5.8% in the control group.
The study, “Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis” (SAMMPRIS), was clearly a key consideration for FDA’s panel review, which took place in March, and the agency has now ended its deliberations with the issuing of its new safety information missive entitled “Stryker Wingspan Stent System: Safety Communication – Narrowed Indications for Use”, which can be found here.
So what does this narrowing amount to? Well, what it doesn’t amount to is a withdrawal of the product from the market, the Humanitarian Device Exemption(HDE) remaining in place. However, while previously the HDE, active since 2005, permitted use in patients with refractory intracranial atherosclerotic disease with 50 percent or greater narrowing in the intracranial arteries, this cohort has now been further tightened to no longer include patients who have suffered recent stroke or patients who have suffered Transient Ischaemic Attacks. In all cases use is only allowed following approval from the treating physician’s Institutional Review Board.
So the agency has stopped short of withdrawing the device, despite pressure from patient and consumer groups to do just that. If you remember, we reported that “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.
Jeffrey Shuren, M.D., director of the FDA’s Center for Devices and Radiological Health said “After careful consideration of available safety information, the FDA believes this device should remain available for this specific subgroup of patients who have exhausted other options.”
It’s another “one of those” situations where a device is in common use in Europe prior to FDA, based on thorough clinical study, issuing a severe usage restriction. Stryker is in the midst of its own European study into the product with what is termed IRISS ( International Registry of the Wingspan™ Stent System), being due for completion around now. Note that the inclusion criteria for that study are significantly broader than FDA’s new indication, including patients with symptomatic intracranial atherosclerotic stenosis, suitable for endovascular treatment and for whom treatment with the Wingspan™ Stent system has been judged necessary by the treating physician.
It’s one thing saying our two continents are differently regulated and plough their own furrows, but surely quite another thing to say that credible clinical data from one side of the pond should not be a consideration on the other. While Stryker will no doubt point to its European multicentre study, some patients being fitted with Wingspan stents in the interim may be being faced with the likelihood of a significantly worse outcome than if they had been managed by conventional means.