Micro-invasive glaucoma surgery (MIGS) devices for glaucoma were big news in 2013. In 2014, MIGS devices represent big dollars. Steven Vold, MD, moderated the panel on the “New Horizons in Glaucoma Devices” at the 2014 Glaucoma 360 meeting.
By Fred Gebhart
In 2013, micro-invasive glaucoma surgery (MIGS) devices to treat glaucoma were big news. In 2014, MIGS devices to treat glaucoma represents big dollars. The first MIGS device, the iStent, has earned more than $20 million in revenues for Glaukos.
Steven Vold, MD, moderated the “New Horizons in Glaucoma Device” session. Four device companies firms offered different solutions to lowering IOP, all pursuing a similar vision of glaucoma management. (Photo by Anthony Lindsay)“Glaukos’ results show the interest is there, the need is there, and the uptake is there,” said Steven Vold, MD, founder and CEO of Vold Vision, Fayetteville, AR. “We are excited to see industry and venture capital and physicians all working together for the common goal of curing glaucoma. Progress over the last five years has made MIGS one of the important parts of my practice.”
Glaukos has led the way in MIGS, but it won’t have the market to itself for long. Dr. Vold moderated an introduction to the future by four of the leading MIGS manufacturers during “New Horizons in Glaucoma Device.” The four firms offer different solutions to lowering IOP, using miniature devices, but all are pursuing a similar vision of comprehensive glaucoma management.
The Xen gelatin stent finished enrollment on its first IDE study in the United States and is enrolling patients for its second IDE trial. Clinical trial data collected on the soft gelatin stent are uniformly encouraging.
“We reduce IOP toward the mid-teens and we are getting significant reductions in glaucoma medication use,” said Barbara Niksch, vice president for clinical and regulatory affairs. “Once we get a month out from implantation, pressures are stable. In the longer term, we are seeing low- to mid-teen IOPs plus continuing medication reduction.”
Xen is a soft, compressible and tissue-conforming stent, designed to mitigate traditional implant issues. The device and its pre-loaded injector can be used with or without cataract surgery. The stent creates an ab interno bleb and drains aqueous using the subconjunctival outflow pathway. Mean IOP drops about 30% from baseline in early generation devices and close to 40% using the latest version plus mitomycin C.
“This is direct subconjunctival outflow that bypasses all potential outflow obstructions,” she said. “There is absolute certainty of outflow and a single implant delivers the desired efficacy. Our international studies demonstrate success in all stages of glaucoma.”
Glaukos created the market for MIGS devices with its iStent. Approved by the FDA in 2012, the device generated good revenues in 2013 and achieved reimbursement in every Medicare region.
Just 1 mm long, the iStent is the smallest medical device known to be implanted in the human body, said Bruce Nogales, chief corporate development officer. The company is already working on two follow-up devices.
Next up in the Glaukos pipeline is the iStent inject, another trabecular meshwork bypass device. Where a single iStent is pre-loaded in a tactile inserter, two iStent injects are pre-loaded in an auto-injection system. An IDE study for combination use with cataract surgery is already underway, a second IDE study for phakic use is set to begin later this year. Glaukos projects approval by 2017.
Farther down the pipeline is the iStent supra, which drains to the suprachoroidal space. An IDE study is currently under way using a single-stent insertion mechanism. The company projects FDA approval in 2018.
“The iStent supra will give us another treatment mechanism to lower IOP,” Nogales said. “We want to get meaningful technologies to the ophthalmologist to help save sight for patients.”
Many glaucoma drug and device manufacturers see IOP reductions in the 30% to 35% range. InnFocus prefers to deal in absolute values. That means a device that could reliably bring IOP down to 14 mm Hg or lower using an inert biomaterial, a shunt design that remains patent without hypotony or leaks and an antiproliferative drug to minimize the initial surgical insult. The result is the InnFocus MicroShunt.
The shunt is made of styrene-isobutylene-styrene (SIBS), the same material used for Taxus-eluting coronary stents. The flexible 8.5-mm device has a 0.07-mm lumen, large enough to allow cells to pass and small enough to prevent hypotony.
“Data from the Dominican Republic and France show an average IOP of 11.2 mm HG that is flat out beyond 2 years,” said Russ Trenary, president and CEO. “Our mean IOP reduction was 55% and 82% percent of eyes had an IOP under 14 mm Hg. We saw an 83% reduction in medication use and 89% of patients were off all glaucoma meds. There were no long-term, sight-threatening adverse events, no endophthalmitis, no chronic hypotony, no choroidal hemorrhage. Now we have to replicate those results in the United States.”
A multicenter IDE trial began in 2013, he continued. The study will compared the InnFocus device to trabeculectomy with a 2-year follow up period.
The eye is one of the few organs in which stenting has not become standard of care. Neurovascular, cardiovascular, pulmonary, gastrointestinal, urological/gynecological, peripheral--the list for stenting procedures is long and growing.
“Stents are common across many other specialties,” said Sean Ianchulev, MD, MPH, chief medical officer and vice president of business development. “I am very happy to see that stent technology is finally coming to ophthalmology.”
Transcend is moving toward market with its CyPass Micro-Stent that drains into the suprachoroidal space. The suprachoroidal space is a compelling surgical target, he said. It is a large, continuous space that can be accessed through a single entry point.
“A single stent creates a permanent conduit for aqueous egress,” he said. “Using the suprachoroidal space creates significant advantages for outflow. It has negative pressure gradient, which drives egress and we can access that space in a very atraumatic way.”
Two-year data from the European Union shows a mean reduction in IOP of 35% with phaco and 32% as a stand-alone procedure with no significant safety concerns. In the United States, the pivotal COMPASS trial completed enrollment with initial results expected in 2015.
“Conventional glaucoma surgery can have some very significant complications,” Dr. Ianchulev said. “We are trying to move toward phaco surgical standards with a procedure that is both highly effective and highly safe for patients.”