FDA issues non-approvable letter for ISTA's T-Pred

ISTA Pharmaceuticals Inc. announced it has received a non-approvable letter from the FDA relating to its new drug application (NDA) for prednisolone acetate 1% and tobramycin 0.3% ophthalmic suspension (T-Pred). The product is being developed as a topical steroid to treat inflammatory ocular conditions for which a corticosteroid is indicated and where bacterial ocular infections or a risk of bacterial infections exists.

"While we are disappointed by the FDA's decision, ISTA is committed to bringing T-Pred to ophthalmologists and patients," said Vicente Anido Jr., PhD, president and chief executive officer of ISTA Pharmaceuticals. "We believe our clinical study met the endpoints that ISTA and the FDA agreed to in the special protocol assessment.

"Nonetheless, the FDA did not find sufficient clinical information to merit approval," Dr. Anido added. "We plan to work closely with the agency to resolve this issue in an efficient manner. We intend to request a meeting with the agency to come to agreement on the actions ISTA Pharmaceuticals must undertake to receive marketing approval for T-Pred."

In the fourth quarter of 2005, ISTA Pharmaceuticals completed its phase III clinical study of prednisolone acetate 1.0% and tobramycin 0.3% ophthalmic suspension. The study was designed as a multicenter, randomized, double-blind study to determine the bioequivalence of prednisolone concentrations between prednisolone acetate 1% and tobramycin 0.3% ophthalmic suspension and prednisolone acetate 1% (Pred Forte, Allergan). ISTA believes its study demonstrated T-Pred achieved or exceeded this goal both in the intent-to-treat and the per-protocol patient populations. In addition, the company said its studies showed T-Pred to have antimicrobial activity equivalent to other combination products approved for this indication.

The FDA assessed the company's clinical data as not showing sufficient equivalence between the prednisolone component in T-Pred and PredForte at least at one of the time points measured nor equivalence in the kill time between the tobramycin components in T-Pred and Tobrex (Alcon Laboratories), although it showed equivalence versus loteprednol etabonate 0.5% and tobramycin 0.3% ophthalmic suspension (Zylet, Bausch & Lomb) and tobramycin 0.3% and dexamethasone 0.1% sterile ophthalmic suspension and ointment (TobraDex, Alcon Laboratories), according to ISTA Pharmaceuticals in a prepared statement.

The company said it plans to request a meeting with the FDA as quickly as possible.