FDA approves preservative-free drug for glaucoma

By Dr. Ananya Mandal, MDFeb 15 2012

The U.S. Food and Drugs Administration (FDA) has approved tafluprost ophthalmic solution (Zioptan, Merck) 0.0015%, the first preservative-free prostaglandin analog ophthalmic solution for glaucoma.

The drug acts by reducing elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. Open-angle glaucoma is the most common form of glaucoma; ocular hypertension is a condition characterized by increased pressure inside the eye.

“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,” George L. Spaeth, Wills Eye Institute, Philadelphia, said in a company press release. “I anticipate using Zioptan in many of these patients in my practice.”

FDA approval of Zioptan was based on efficacy and safety results from 5 controlled clinical studies of up to 2 years in 905 patients. Both preservative-containing and preservative-free formulations of tafluprost were used in these clinical studies. Zioptan was shown to have IOP-lowering effects. In clinical studies of up to 2 years, Zioptan, dosed once-daily in the evening, lowered IOP at 3 and 6 months by 6 mmHg to 8 mmHg and 5 mmHg to 8 mmHg, respectively, from a baseline pressure of 23 mmHg to 26 mmHg.

In clinical trials of patients receiving either preservative-containing or preservative-free Zioptan, the most common pooled adverse reaction observed was conjunctival hyperemia which was reported in a range of 4% to 20% of patients.

Zioptan has been reported to cause changes to pigmented tissues. The most frequently reported changes have been increased pigmentation of the iris, periorbital tissue (eyelid) and eyelashes. Pigmentation is expected to increase as long as Zioptan is administered, according to the press release from Merck. After discontinuation of Zioptan, pigmentation of the iris is likely to be permanent but pigmentation of the periorbital tissue has been reported to be reversible in some patients. Patients who receive treatment should be informed of the possibility of increased pigmentation. The long-term effects of increased pigmentation are not known. Iris color change may not be noticeable for several months to years.

Zioptan should be used with caution in patients with active intraocular inflammation (e.g., iritis/uveitis) because the inflammation may be exacerbated. Macular edema, including cystoid macular edema, has been reported during treatment with prostaglandin F2α analogs, the press release also said. There are no adequate and well-controlled studies in pregnant women. Zioptan should not be used during pregnancy unless the potential benefit justifies the potential risk to the fetus.

Merck expects Zioptan to become available to customers next month, priced at $97 for a 30-day supply, a company spokeswoman said. Zioptan enters a market with generic options. Pfizer Inc.'s Xalatan eye solution recently lost market exclusivity in major countries, clearing the way for cheaper generic copies. Merck also has older drugs designed to reduce intraocular pressure, Trusopt and Cosopt, which have lost market exclusivity in the U.S. and some other countries.