Allergan’s minimally invasive Xen gel stent has shown it can lower IOP and reduce topical medication use without the inherent risk of traditional drainage surgery.
The FDA last week approved the XEN45 Gel Stent and the XEN Injector for patients with refractory glaucoma who failed previous surgical treatment or in patients with primary open angle glaucoma, pseudoexfoliative or pigmentary glaucoma with open angles that are unresponsive to maximum tolerated medical therapy.
Dr. Rohit Varma, director of the USC Roski Eye Institute and dean of the Keck School of Medicine of USC, led the work to secure FDA approval. He calls the device a “game changer", especially for patients who failed surgery.
The stent is a soft, permanent, subconjunctival implant that shunts fluid from the anterior chamber to the subconjunctival space. Approximately 6-mm long and the width of a human hair, the stent comes preloaded in a disposable Xen injector and is implanted through a small, self-sealing corneal incision. The stent’s collagen-derived non-inflammatory gelatin material allows it to conform to the ocular tissue, possibly minimizing many of the issues seen with synthetic materials such as migration, erosion and corneal endothelial damage.
In the pivotal trial conducted in refractory glaucoma patients, XEN reduced IOP from a mean medicated baseline of 25.1 (+ 3.7) mmHg to 15.9 (+ 5.2) mmHg at 12 months postop. The mean baseline number of IOP-lowering medications was 3.5 versus an average use of 1.7 medications at 12 months. XEN also allows for keeping postoperative options open, allowing physicians to utilize other IOP-reduction techniques should they be required after surgery.
"Xen is a new option that provides an opportunity for surgical intervention in refractory glaucoma patients. Xen can effectively lower IOP, in fact, studies have shown that at 12 months using Xen, patients used on average less IOP lowering drops than they did before XEN was implanted," said Robert N. Weinreb, MD, chairman and distinguished professor of Ophthalmology at the University of California, at San Diego.
Allergan plans to launch the device in the US in early 2017. Xen is already approved for use in the EU, Canada, Switzerland and Turkey, with more than 10,500 stents distributed worldwide.