ISTA Pharmaceuticals Inc. won FDA approval of Vitrase for use as a spreading agent to facilitate the dispersion and absorption of other drugs. Meanwhile, the firm is awaiting approval on an earlier new drug application for Vitrase as a single injection to the eye for vitreous hemorrhage.
The firm's stock (NASDAQ: ISTA) Thursday fell 32 cents to close at $14.48.
Irvine, Calif.-based ISTA will delay the launch of Vitrase for three to six months while it files a supplemental NDA seeking approval of a smaller vial size at a dose concentration of 50 units/mL, which is believed to be optimal for use as a spreading agent. But Vitrase will be available July 1 as samples for physicians who want to use it, Anido said.
ISTA expects to officially launch Vitrase both as a spreading agent and in the smaller vial dosing form by the end of the year. As a spreading agent, Vitrase's label is fairly general, said Vicente Anido, president and CEO of ISTA, who told BioWorld Today the agent also could be used in cataract, retinal and glaucoma surgeries. Outside ophthalmology, Anido believes Vitrase has a future as a spreading agent in other areas, including cancer.
In cataract surgery alone, ISTA believes Vitrase could fetch $50 million to $70 million a year in the U.S. Over the next few months, though, the firm will define other uses for the product. For now, the approved label says, "Vitrase is indicated as an adjuvant to increase the absorption and dispersion of other injected drugs, for hypodermoclysis, and as an adjunct in subcutaneous urography for improving resorption of radiopaque agents."
Also, the label gives directions for reconstitution of Vitrase in five dose concentrations, facilitating its use for different conditions from a single vial of 6,200 units. Clearing Vitrase (hyaluronidase for injection; lyophilized, ovine) for marketing removes hyaluronidase from the FDA's drug-shortage list, where it has been since 2001 due to a lack of companies manufacturing it.
Hyaluronidase often is used for rehydrating patients after surgery and as a spreading agent in a number of surgeries. Vitrase is a proprietary formulation of highly purified, preservative-free ovine hyaluronidase, the company said. Now that Vitrase has been cleared for approval, the company likely will shift some of its focus back to the vitreous hemorrhage indication. Little more than a year ago, the FDA issued an approvable letter for the indication, pending further data analysis and possibly a confirmatory study based on that analysis. (See BioWorld Today, April 8, 2003.)
In early fourth-quarter 2003, ISTA submitted more information on the indication.
"Now we are going to try to find out if the data we turned in get us any closer to an approval or if we need to do another trial," Anido said. Whatever the case, Vitrase will be on the market so it can be used off-label in the hemorrhage indication. Outside of Vitrase, ISTA has a few other promising products swiftly approaching the finish line. The most advanced is Istalol, a formulation of the beta-blocker timolol developed by Senju Pharmaceutical Co. Ltd., of Osaka, Japan. While the FDA slowed ISTA's progress by issuing an approvable letter that asked for manufacturing data on the candidate last summer, the firm now believes it is poised to win approval this quarter, as it has cleared up manufacturing issues. (See BioWorld Today, July 29, 2003.)
Behind Istalol, ISTA plans to submit an NDA this quarter for Xibrom (bromfenac sodium ophthalmic solution), a topical, non-steroid solution being developed to treat ocular inflammation following cataract surgery. It offers an advantage to marketed products because of its twice-daily dose - its competitors are dosed four times daily. (See BioWorld Today, March 10, 2004.)
If approved, it could be launched in the first half of 2005. With all this going on, ISTA is preparing to build a sales team. Anido said the company will sell Vitrase in the U.S. in the spreading indication on its own, but it is partnered with Allergan Inc., of Irvine, and Otsuka Pharmaceutical Co. Ltd., part of the Otsuka Group of Tokyo, in the vitreous hemorrhage indication.