New glaucoma drug approved by FDA. It’s been called the “silent thief of sight” because it causes gradual vision loss over a long time. By the time you notice the symptoms, the disease is quite advanced and even with treatment, ten percent of sufferers still end up blind.
It’s glaucoma, and it’s the second leading cause of blindness globally, after cataracts, affecting one in 200 people aged 50 and younger—with that number rising to one in 10 for people over the age of eighty.
Over 60.5 million people worldwide and 120,000 Americans have glaucoma and by 2020, ophthalmologists estimated that their numbers will rise to 79.6 million. The numbers in China and India are bigger, and the disease is a leading cause of blindness among African Americans.
But glaucoma presents a great public health challenge because the blindness it causes is irreversible. Worse, only half of the people who have glaucoma know that they have it.
Treatment is aimed at further preventing further vision loss. But if the condition is detected early enough, it’s possible to arrest the development or slow the progression with medical and surgical means.
Ocular hypertension (increased pressure within the eye) is the most important risk factor in most glaucomas, and the key to treatment is keeping the eye pressure within normal bounds.
On Feb. 14, the U.S. Food and Drug Administration approved a new solution to treat this common but deadly eye condition.
The drug, manufactured by pharmaceutical giant Merck & Co is called Zioptan, whose active ingredient is tafluprost. It’s previously been approved for use in certain European countries under the brand Saflutan.
Zioptan treats ocular hypertension. Patients with ocular hypertension frequently are considered to have a greater chance of developing glaucoma.
The drug is also approved to treat elevated intraocular pressure in people with a form of glaucoma known as open-angle. This form of glaucoma, the most common form of the disease, involves mounting pressure on the optic nerve.
Zioptan is a prostaglandin analog ophthalmic solution. Most solutions like this use preservatives that are linked to side effects. But Merck claims Zioptan is the first preservative-free prostaglandin analog ophthalmic solution.
“Zioptan’s approval provides an alternative treatment option for patients living with this potentially blinding disease,” says Dr. Edward Cox, M.D., M.P.H, director of the Office of Antimicrobial Products in FDA’s Center for Drug Evaluation and Research.
“Prostaglandin analogs are often used as a first line of treatment to lower intraocular pressure in patients with open-angle glaucoma. The approval of Zioptan will provide a new, effective option to lower IOP,” says Dr. George L. Spaeth of the Wills Eye Institute in Philadelphia. “I anticipate using Zioptan in many of these patients in my practice,” he says in a company press release.
FDA approved Zioptan based on the efficacy and safety results of five controlled clinical studies that enrolled 905 patients for up to two years. Both preservative-containing and preservative-free formulations of tafluprost were used in these clinical studies.
In clinical studies of up to two years long, patients with open-angle glaucoma or ocular hypertension treated with Zioptan in the evening showed reduced eye pressure at three and six months.
Particularly, pressure was reduced by 6-8 mmHg at three months and by 5-8 mmHg at six months, from a baseline pressure of 23-26 mmHg. Eye pressure is measured in millimeters of mercury (mm Hg), a measure of fluid pressure in the eye. Normal eye pressure ranges from 10-21 mm Hg. If pressure is greater than 21 mm Hg, it’s considered to beocular hypertension.
Beginning this March, Merck expects Zioptan to become available to U.S. consumers, priced at US$97 for a 30-day supply, a company spokeswoman told the Wall Street Journal.
Because Pfizer Inc’s Xalatan eye solution recently lost market exclusivity in major countries, clearing the way for cheaper generic copies, so Zioptan enters a market with generic options.
Trusopt and Cosopt, two of Merck’s older drugs designed to reduce intraocular pressure have also lost market exclusivity in the U.S. and some other countries.
The drug was developed in cooperation with specialist drug maker Santen Pharmaceutical, an Osaka, Japan-based company that specializes in ophthalmic and anti-rheumatic fields.
Zioptan Dos and Don’ts
Before using Zioptan
DO tell your doctor if you:
• have or have had eye problems including any surgery on your eye or eyes
• are using any other eye medicines
• have any other medical problems
• are pregnant or plan to become pregnant. It isn’t known if Zioptan will harm your unborn baby.
• if you are breastfeeding or plan to breastfeed. It isn’t known if Zioptan passes into your breast milk.
• if you become pregnant while using Zioptan
• about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.
DO know the medicines you take. Keep a list of them to show your doctor and pharmacist when you get a new medicine.
DON’T use Zioptan for
• people who have active intraocular inflammation (e.g., iritis/uveitis) because the inflammation may be worstened
• people who have macular edema, including cystoid macular edema. And it should be used with caution in aphakic patients, in pseudophakic patients with a torn posterior lens capsule, or in patients with known risk factors for macular edema.