Abbott Receives Clearance From the U.S. Food and Drug Administration -FDA- To Market New Epilepsy Drug.

ABBOTT PARK, Ill.--(BW HealthWire)--Oct. 2, 1997--

- Gabitril(TM) (tiagabine hydrochloride) is the first antiepileptic believed to target the major inhibitory neurotransmitter GABA -

Abbott Laboratories announced today it has received regulatory clearance from the U.S. Food and Drug Administration (FDA) to market Gabitril(TM) (tiagabine hydrochloride). Gabitril will be available for the adjunctive treatment of partial seizures, a form of epilepsy, offering a new option to those who suffer from the disorder. There are approximately 2.5 million Americans who have some form of epilepsy and there are an estimated 125,000 new cases diagnosed each year.

Gabitril is indicated as adjunctive therapy in adults and children 12 years and older in the treatment of partial seizures. Gabitril will be available by prescription in pharmacies nationwide in October.

The effectiveness of Gabitril when added to an existing regimen of at least one other antiepilepsy drug (adjunctive therapy) was examined in three multi-center, double-blind, placebo-controlled, parallel group clinical trials in 769 patients with refractory partial seizures, as well as two placebo-controlled cross-over studies in 90 patients. Gabitril as adjunctive therapy was statistically superior to placebo in controlling partial seizures.

The efficacy of Gabitril as adjunctive therapy was evaluated using two outcome measures: the median reduction in seizure rates, and the proportion of patients whose seizure frequency was reduced by at least one-half. Using both of these measurements, the regimen containing Gabitril significantly reduced partial seizure rates, compared to placebo.

The most commonly observed adverse events associated with the use of Gabitril in combination with other antiepilepsy drugs versus placebo were dizziness/light-headedness (27% vs. 15%), asthenia/lack of energy (20% vs. 14%), somnolence (18% vs. 15%), nausea (11% vs. 9%), nervousness/irritability (10% vs. 3%), tremor (9% vs. 3%), abdominal pain (7% vs. 3%) and thinking abnormal/difficulty with concentration or attention (6% vs. 2%).

As with other antiepileptics, Gabitril should not be stopped abruptly unless medically indicated. Adverse events most often associated with Gabitril were related to the central nervous system.

The precise mechanism of action by which Gabitril exerts its antiseizure effect is unknown, although it is believed to be related to its ability, documented in in vitro experiments, to enhance the activity of gamma aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. In vitro experiments have shown that Gabitril binds to recognition sites associated with the GABA uptake carrier. It is thought that, by this action, Gabitril blocks GABA uptake into presynaptic nerve cells, permitting more GABA to be available for receptor binding on the surfaces of post-synaptic nerve cells. This suggests that Gabitril prevents the propagation of neural impulses that contribute to seizures by GABA-ergic action.

Epilepsy is a chronic disorder characterized by recurrent seizures due to a central nervous system dysfunction. A seizure is a brief, excessive surge of electrical activity in the brain that causes a change in how a person feels, senses things, or behaves. Epileptic seizures cause temporary impairment of brain function. During a seizure, a person with epilepsy might have convulsive movements, lose awareness, or feel a pricking sensation.

Seizures are classified on the basis of their origin in the brain. Seizures that begin with widespread, excessive electrical discharge simultaneously involving both sides of the brain are called primary generalized seizures; and seizures that begin with an abnormal burst of electrical activity in a small portion of the brain are called partial seizures. Partial seizures are divided into two main types, depending on whether consciousness is preserved. During simple partial seizures the person is alert, able to respond to questions or commands, and can remember what occurred during the seizure. During complex partial seizures, the ability to pay attention or respond to questions or commands is impaired. Often there is no memory of what happened during all or part of the seizure.

"New epilepsy drugs are needed, as there are people with epilepsy who are still experiencing partial seizures despite taking medications," says Steven Schachter, M.D., director of clinical research at Beth Israel Deconess Medical Center in Boston, MA. "Gabitril is an exciting development."

Gabitril enhances Abbott Laboratories' long-standing commitment to developing new treatments for epilepsy. Abbott introduced its first antiepilepsy drug in 1946.

Gabitril is licensed from Novo Nordisk A/S of Denmark and has cleared regulatory review in 15 countries, including Australia, Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Portugal, Spain and Switzerland.

Abbott Laboratories is a diversified, global health care company devoted to the discovery, development, manufacture, and marketing of pharmaceutical, diagnostic, nutritional, and hospital products. The company employs 54,000 people and markets its products in more than 130 countries. In 1996, the company's sales and net earnings were $11.0 billion and $1.9 billion, respectively, with earnings per share of $2.41.

Abbott's news releases and other company information are available on the company's web site at http://www.abbott.com.

CONTACT: Abbott Laboratories

Kim Modory, 847/938-8439

Rick Moser, 847/937-2654