Megan Polanin, PhD, National Center for Health Research: June 12, 2018
Thank you for the opportunity to speak today on behalf of the National Center for Health Research. I am Dr. Megan Polanin. Our research center analyzes scientific and medical data and provides objective health information to patients, providers, and policymakers. We do not accept funding from industry, so I have no conflicts of interest to report.
As a high-risk device, the INCRAFT AAA Stent Graft System should be held to a high standard for approval. Given the severity of infrarenal abdominal aortic aneurysms, I think we can all agree that a device used to treat this condition should be safe and effective for patients whose health depends on it.
We have several serious concerns about this device:
1) There are too few women in the study. Women represent about 20% of AAA patients, and, as we heard this morning, women with AAAs can be more challenging to treat due to smaller vessel size. Even though women were included, there are only nineteen women in this study, which is too few to provide meaningful data.
2) Basing approval on an open label, single arm study of 190 participants introduces bias and does not allow for comparison with patients receiving no treatment at all. Though we recognize that comparative effectiveness research is not the standard in the field due to the challenges of such research, it is nearly impossible to ascertain the relative benefit/risk ratio of this device.
3) Safety is a major concern as this device resulted in higher than expected adverse events. In the pivotal study, this device showed a higher rate of transrenal stent fractures than the alternative endovascular treatment options (10% of subjects with 38 total fractures; 37% of these patients had multiple fractures). In fact, as the FDA reported, at year 1, the fracture rate for the INCRAFT device was twice the highest previously reported rate. Most of the fractures were not identified properly by trial site clinicians.
With longer follow-up, the number of patients with at least 1 stent fracture continues to rise. Thus, all patients who may use this device would be at risk for developing fractures — with no information about who might be at higher risk or what the long-term implications are.
The FDA noted that the number of Type II endoleaks is higher at follow-up than they have seen for other endovascular graft devices. In addition, aneurysm expansion beginning at the 2-year mark and the number of patency-related events through 1 year are higher than reported for similar devices.
As you determine whether you have reasonable assurance of this device’s safety and effectiveness, we urge you to consider the benefits and risks for patients. Do you currently have enough information to feel confident that this device has benefits outweighing its risks? Would you recommend this device for a loved one, friend, or your own patients?
Thank you for the opportunity to share our perspective.
The Circulatory System Devices Panel of the Medical Devices Advisory Committee Meeting voted 11-4 that the benefits of the INCRAFT AAA Stent Graft System outweigh the risks for use in patients who meet the criteria specified in the proposed indication. Read more about the meeting here.