Alcon has voluntarily withdrawn its glaucoma device CyPass Micro-Stent after five-year data linked it to the loss of endothelial cells.
The Novartis unit told physicians to immediately stop treating patients with the implant and return unused devices.
Despite the withdrawal, Novartis has retained its 2018 sales forecast and still plans to spin off Alcon in the first half of next year.
CyPass Micro-Stent is a small tube that is implanted below the surface of the eye to lower pressure in the organ and thereby reduce or eliminate the need for a patient to take glaucoma medications. The device proved to be effective and relatively safe in clinical development, leading the FDA to clear it for use in adult patients with mild-to-moderate primary open-angle glaucoma in 2016.
After posting the positive two-year clinical trial data, Alcon continued to track subjects for another three years. The resulting five-year data showed patients treated with CyPass Micro-Stent suffered statistically-significant endothelial cell loss compared to the control cohort, leading Alcon to pull all versions of its device from the market.
Alcon’s press release lacks a proposed explanation for why the device may be causing endothelial cell loss but the company’s CMO Stephen Lane was more forthcoming in a letter to physicians, according to the American Academy of Ophthalmology. Lane reportedly thinks the damage stems from the device’s position. Cell loss is correlated to the number of retention rings seen in assessments of the eye’s internal drainage system. The rings keep the device in place and guide its insertion depth.
During clinical development, 2% of patients treated with CyPass Micro-Stent were harmed because it was positioned incorrectly. Some of these patients experienced progressive endothelial cell loss. The mispositioned devices were identified within a week but longer-term problems still arose. Three patients in the two-year analysis lost 30% or more of their endothelial cells.
The adverse event was rare enough at the two-year point for the benefits of the device to be deemed to outweigh the risks. However, the five-year results have tipped the risk-benefit balance.
Novartis told Reuters its sales forecasts and spin off plans are unaffected by the withdrawal. The setback could have a bigger effect on Alcon’s rivals, though. Shares in Glaukos, which markets rival device iStent, rose 40% following news of Alcon’s withdrawal. The gain reflects the strengthened competitive position of iStent, although Alcon plans to return CyPass Micro-Stent to the market with a revised label at some point.