MIGS Minus One: What’s Next?

With Alcon’s voluntary withdrawal in late August of the CyPass MicroStent due to safety concerns, many have been wondering how the rest of the class in the micro-invasive glaucoma surgery (MIGS) space will fare. Alcon is, after all, a major player and when it advises surgeons to “immediately cease further implantation” and return unused devices, the market takes notice.

Market Reaction

Glaukos Corp., for one, seemed to benefit the most from the news. The week the news broke, Glaukos was trading between $43 and $44/share. Once the CyPass news hit, though, Glaukos stock jumped to $66.43/share, and has settled to between $60 and $64/share. Glaukos markets the iStent, and recently had its iStent Inject (its next-generation device) approved by the Food and Drug Administration.

Novartis, Alcon’s parent company, was relatively unphased by the news, as shares fell less than 1% (from $83.82/share at the beginning of the week to $83.02/share by the end of the week).

Allergan’s stock was unphased by the news (it markets the XEN Gel Stent). Ivantis, marketers of the Hydrus Microstent, is privately held.

Alcon’s decision and corresponding recommendation is based on an analysis of five-year post-surgery data from the COMPASS-XT long-term safety study that showed statistically significant endothelial cell loss (ECL) in the CyPass/cataract surgery group compared with the group that underwent cataract surgery alone. (As an aside, parent company Novartis notes the CyPass withdrawal has not affected plans to spin Alcon off next year).

Glaucoma Specialists’ Reaction

The news surprised some glaucoma specialists as well. Iqbal (Ike) K. Ahmed, MD, FRCSC, assistant professor at the University of Toronto, tells Eye on Innovation that in his 12-year history with the device from the “early development to the early implantations to investigations and then using it in the commercial sense,” he had not seen the types of ECL that caused the withdrawal in the first place, although he “fully supports” Alcon’s decision.

As for the overall MIGS category, Dr. Ahmed says it’s a “kick to the gut. It’s a little bit unnerving both for existing patients and surgeons.”

Placement and location of the device in terms of proximity to the cornea may have had a role in the cell loss data, Dr. Ahmed notes. The CyPass is placed in the suprachoroidal space, whereas the iStent and Hydrus are placed in the trabecular meshwork; Allergan’s XEN is a translimbal implant that targets the subconjunctival space.

“Any device that’s placed near the cornea could have this kind of issue if placed too close. We’ve seen it with lens implants and tube shunts,” Dr. Ahmed explains. He remains optimistic that Alcon will re-assess the data, patient selection, and device placement and potentially re-introduce the device in the near future.

Getting Another Look?

There seems to be reason to believe Alcon might do exactly that.

In a press release immediately after the withdrawal, Stephen Lane, MD, Alcon’s chief medical officer, said, “Although we are removing the product from the market now out of an abundance of caution, we intend to partner with the FDA and other regulators to explore labeling changes that would support the re-introduction of the CyPass MicroStent in the future.”

Numerous surgeons and patients are now “quite concerned about the loss of an implant that actually has done quite well in most surgeons’ hands,” Dr. Ahmed said.

He was even more emphatic about the overall class of devices, saying it’s “not a class effect,” and noting different materials, placement, and designs make each of the MIGS devices unique.

For instance, Glaukos’ iStent – which is placed in Schlemm’s canal – passed the five-year follow-up in 2012 and has been implanted more than 400,000 times without any cause for concern about ECL. Analysts believe any issues with ECL loss from devices placed into the trabecular meshwork do not exist, citing the FDA’s approval of both the iStent Inject and the Hydrus in the past few months.

For questions about this article, please contact Michelle Dalton at mdalton@dalton-and-associates.com.