Standard first-line glaucoma treatments to lower intraocular pressure (IOP), such as eye drops, commonly have poor patient adherence, which may result in inadequate pressure control and lead to optic nerve damage and loss of vision over time.
However, results from two phase 3 studies indicate that a new FDA-approved intracameral biodegradable sustained-release implant—the first of its kind—could provide better long-term control of IOP in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).
Felipe Medeiros, MD, PhD, a Duke glaucoma specialist and principal investigator for the study of the sterile intracameral implant (DURYSTA, Allergan: Dublin, Ireland), says this new treatment has the potential to shift the paradigm for treating glaucoma, which affects more than 80 million people globally.
The implant contains 10 mcg of bimatoprost in a solid polymer sustained-release drug delivery system. Bimatoprost is believed to lower IOP by increasing outflow of aqueous humor through the trabecular meshwork and uveoscleral routes.
At the March 2020 American Glaucoma Society meeting, Medeiros presented the results from the two 20-month phase 3 ARTEMIS studies evaluating more than 1,100 participants with OAG or OHT on the safety and efficacy of the implant versus twice-daily topical timolol eye drops. Participants received an implant every four months for one year, and results showed that the implant reduced IOP by approximately 30%. Notably, Medeiros and his team of researchers observed that after the third implant, more than 80% of patients did not require any medication up to a year after the last implant.
“One of the most important things that emerged from these studies is that the group using the implant had slower changes in the visual field compared to the group that was randomized to timolol,” says Medeiros, who is also vice-chair for technology and director of the clinical research unit at the Duke Eye Center. “That’s of fundamental importance because the goal of glaucoma treatment is to preserve visual function.”
Medeiros notes that several studies have shown medication adherence for patients with glaucoma is typically less than 50%—though he says that “when patients are not being monitored in the context of a study, adherence may be even lower.” Some reasons for low adherence include side effects from the eye drops (including discomfort, burning, or redness); forgetfulness; and coexisting systemic conditions such as rheumatoid arthritis, which may make it more difficult for patients to administer the eye drops as directed.
The results of the phase 3 ARTEMIS studies indicate that the benefits of this implant are significant for patients, Medeiros says, and may even extend to relatives of patients with glaucoma: “Frequently, a relative or a significant other is the one to administer the eye drops, and it can be a lot of effort.”
Medeiros is currently involved with several additional phase 3 studies to further investigate the frequency of administration. “We expect that it’s not necessary to administer it every four months, as we did in the trial, but maybe every six months to a year for some patients,” he says. “Currently, the implant is approved by the FDA for a single application, but we hope the results of these studies will allow for an expansion of the label for multiple applications.”