Durysta eliminates the need for cumbersome eyedrops.

It’s well known that administering eyedrops poses challenges for patients.

Margot L. Goodkin, MD, PhD, executive director, Clinical Development, at Allergan, says that some patients may have physical challenges that make using drops difficult. In addition, some patients may forget to use their eyedrops or have to juggle administering several medications per day.

For patients with open-angle glaucoma or ocular hypertension, Allergan’s Durysta may be a good option. It is the first FDA-approved intracameral, biodegradable sustained-release implant indicated to reduce IOP in these patients.

“Durysta takes the hassle out of using eyedrops to treat glaucoma, and the medication doesn’t have preservatives like drops do,” says Randy Craven, MD, chief, Wilmer Eye Institute at Bethesda, vice chair of Wilmer Practice Network and associate professor at Johns Hopkins University School of Medicine, located in Bethesda, Md. “The implant provides continual delivery of bimatoprost for a long period of time, so if patients forget to use their drops or don’t get their refill on time, they still have the comfort of knowing that the drug is being delivered.”

Furthermore, the implant benefits ophthalmologists by putting the treatment into their hands rather than in patients’ hands, Dr. Goodkin says.

“It allows physicians to get away from the unknown variable of whether or not a patient is using their medication,” adds Dr. Craven.

HOW IT WORKS

Durysta is delivered directly into the eye’s anterior chamber, where the tissues involved in lowering IOP are located. It works by enhancing aqueous outflow from the eye, Dr. Goodkin explains.

When initially administered into the eye, Durysta is in the form of a small particle, like a tiny grain of salt. After it’s placed into the eye, the compound (comprised of 10 mcg of bimatoprost, a prostaglandin analog) is slowly metabolized and releases the drug into the eye, Dr. Craven explains. As it’s metabolized, it turns into water and carbon dioxide and slowly disappears. In a Phase 3 clinical trial, Durysta took a year to dissipate in some patients and for others it took less time.¹

In a Phase 1/2 study, about 25% of patients had their eye pressure controlled for up to 2 years.² Also, Durysta reduced IOP by approximately 30% from baseline over a 12-week period in two Phase 3 studies.¹

THE IMPLANT PROCEDURE

The administration can be performed in an exam room or in a minor surgical room. The procedure itself takes less than 10 minutes.

Durysta is preloaded into a single-use, handheld, pen-like applicator containing a small needle. The needle enters the anterior chamber of the eye through the clear cornea. The implant is then released by pressing a button located on the applicator.

The procedure is done under magnification, giving the ophthalmologist clear visualization of the anterior chamber structures, Dr. Goodkin says. Sterile conditions help mitigate the risk of ocular infection. A topical anesthetic is used to numb the eye, and it also helps to stabilize the patient’s head during administration, which minimizes risk of ocular trauma from the patient’s own movement. Afterward, the physician checks for aqueous leakage where the needle was inserted to ensure that it is self-sealing.

Some degree of discomfort is expected following the procedure, such as slight irritation of the eye from the procedure preparation, in which drops and an eyelid speculum were inserted. In Phase 1/2 and Phase 3 studies, there were low incidences of side effects typically associated with prostaglandin analog medications after administration, and a few patients had inflammation. However, there were no significant issues with IOP control, such as pressure spikes or pressure being too low, Dr. Craven says. A few patients had transient IOP elevation after administration, but not to a degree of concern.^1,2

CLINICAL IMPLICATIONS

Patients in clinical trials had open-angle glaucoma, ocular hypertension or two of the most common forms of secondary open-angle glaucoma: pigmentary glaucoma and pseudoexfoliation glaucoma. Other diagnoses weren’t studied, Dr. Goodkin says, because an open angle is required in order to have enough space for the implant.

Patients enrolled in the trials had a lens (either a natural lens or artificial lens) in place and no scarring or other findings that would prevent the implant from settling into the anterior chamber angle.

Durysta is contraindicated in patients with active or suspected ocular or periocular infections; corneal endothelial cell dystrophy (eg, Fuchs’ dystrophy); prior corneal transplantation or endothelial cell transplants; absent or ruptured posterior lens capsule, due to the risk of implant migration into the posterior segment; and hypersensitivity to bimatoprost or to any other of the product’s other components.

ADDITIONAL BENEFITS

Durysta does not contain preservatives — just 10 mcg of bimatoprost, a commonly used glaucoma drop that has been available for years and has a long track record of safety and efficacy. “The amount of medication contained within the implant is equivalent to one drop of a medication for glaucoma,” Dr. Craven says. “It’s amazing that such a small amount of drug, when inserted into the eye, can control pressure for such a long time. The amount of a patient’s exposure to bimatoprost is significantly reduced with the implant.”

Dr. Craven believes that providing a continual release of medication into the eye could potentially have even more positive effects, which have yet to be studied.

WHAT ELSE YOU SHOULD KNOW

Durysta is FDA approved for one intracameral administration per eye, because the long-term effects on the cornea endothelium are currently unknown. The product’s prescribing information states that the presence of Durysta implants has been associated with corneal adverse reactions and increased risk of corneal endothelial cell loss.³ Use caution when prescribing Durysta to patients with limited corneal endothelial cell reserve, Dr. Goodkin says.

In controlled studies reported in the product’s prescribing information, 27% of patients had conjunctival hyperemia, the most common ocular adverse reaction. Furthermore, 5% to 10% of patients reported foreign body sensation, eye pain, photophobia, conjunctival hemorrhage, dry eye, eye irritation, an increase in IOP, corneal endothelial cell loss, vision blurred, iritis and headache.³

“Durysta was well tolerated in the majority of patients,” Dr. Goodkin concludes. OM

REFERENCES

1. Craven ER, Walters T, Christie W, et al. Phase 3 evaluation of bimatoprost sustained-release implant in patients with glaucoma or ocular hypertension: results at primary database lock. American Academy of Ophthalmology Annual Meeting. San Francisco, Calif. October 2019. Oral presentation.
2. Craven ER, Walters T, Christie WC, et al. 24-month phase I/II clinical trial of bimatoprost sustained-release implant (Bimatoprost SR) in glaucoma patients. Drugs. 2020;80:167-179.
3. DURYSTA [Prescribing Information]. Irvine, Calif.: Allergan, Inc.; 2020. https://media.allergan.com/products/durysta_pi.pdf . Accessed: July 13, 2020.