The US Food and Drug Administration (FDA) recently posted a safety warning stating that off-label use of Stryker’s Wingspan stent system could increase the risk of stroke or death. This warning came on 25 April, shortly after results from a mandated post-market surveillance study were released.

The Wingspan stent has been tested in multiple clinical trials. The first was SAMMPRIS, a paradigm-shifting trial that tested percutaneous transluminal angioplasty and stenting (PTAS) using Stryker’s Wingspan stent versus aggressive medical therapy alone in the treatment of patients with intracranial atherosclerotic disease (ICAD).

The SAMMPRIS trial concluded that aggressive medical management was superior to PTAS. Results from this trial led the FDA to severely narrow the indications of the Wingspan stent. It is now indicated for patients ages 22–80 years with a history of two or more strokes, with the most recent stroke having occurred more than seven days prior to the stenting procedure, and who have 70–99% stenosis in their intracranial artery. Patients should also have recovered well from their last stroke and have a modified Rankin score (a measurement of the degree of disability) of three or less.

The SAMMPRIS trial heavily influenced physicians’ decision making in the treatment of ICAD patients in multiple countries including Australia, Canada, France, Italy, Portugal, Saudi Arabia, Spain, the UK, and the US.

In general, intracranial stenting is still performed in rare cases, but only when other forms of medical therapy have failed. To further understand the risks associated with this device, the FDA mandated the “Wingspan StEnt System PostmArket SurVEillance” (WEAVE) study, which has now been completed. In its recent safety warning, the FDA reported that patients who met the FDA-approved indications had a 2.6% combined rate of stroke or death, while patients who did not meet the FDA-approved indications had a 23.9% combined rate of stroke or death. These results led the FDA to reiterate that only a select group of patients who fit the current indications and enrolment criteria for the WEAVE study may benefit from the use of Stryker’s Wingspan stent for the treatment of ICAD.

Despite these negative results, Stryker’s Wingspan stent still remains the only approved intracranial stent for the treatment of ICAD available on the US intracranial stenting market, which GlobalData estimated at $8.87m in 2018. However, epidemiological considerations mean that ICAD is a much more prevalent disease in the Asia Pacific region, where it results in up to four times as many acute ischemic stroke cases.

This heavy disease burden has resulted in a greater number of intracranial stenting procedures being performed, and markets with a higher potential for growth. While the Wingspan stent is available in China, MicroPort Scientific Corp has the dominant share in the market. Chinese sales of the APOLLO (MicroPort) stenting system are experiencing high levels of organic growth, driven by a number of factors including strong product promotion, industry-funded training programs for doctors and positive clinical trial data released in 2015.

Given the pre-existing negative public perception of the Wingspan stent due to the SAMMPRIS trial and the recent FDA warning, GlobalData expects that most intracranial stenting markets outside of Asia Pacific will remain steady or even decline in the foreseeable future. The usage of Stryker’s Wingspan stent system, in particular, will likely decline in the face of added negative perception from the WEAVE trial.

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