Abstracts

RATIONALE: Observational studies provide additional information on the safety and efficacy of new drugs gathered under daily practice conditions that is essential for the prescribing physician. We report the interim results of a large multinational observational study of add-on tiagabine therapy in patients with partial epilepsy, with or without secondary generalisation, not satisfactorily controlled with other antiepileptic drugs (AEDs).
METHODS: A total of 1600 patients was planned to be enrolled in an open, non comparative, multicentre (9 countries), 6-month study, followed optionally by a further 6-month treatment period. A fixed-scheduled titration of tiagabine by 5mg weekly increments up to a maintenance daily dose of 15 to 50mg (depending on whether or not patients were simultaneously receiving enzyme inducing drugs)was recommended. But at any time, the dose could be adjusted to individual patient needs, at the discretion of the investigator. Four visits were scheduled during the first 6-month treatment period (baseline, after 6 weeks, 3 months and 6 months), with two additional visits at 9 and 12 months. Safety was assessed by spontaneous reporting of adverse events (AEs). Proportion of responders (i.e. patients with at least a 50% reduction in seizure rate from baseline) was assessed (primary endpoint), as well as the proportion of seizure free patients and mean changes in seizure rate from baseline.
RESULTS: The study is still ongoing. As of March 2001, 163 patients (50.3% male) aged 36.8 (+/-15.3) years have been included who had at least one efficacy evaluation after baseline. Mean duration of epilepsy was 16.5 (+/-13.1) years, with 16.5% of patients having epilepsy for more than 30 years. Epilepsy was symptomatic in 48.5% of patients, and non symptomatic in 47.3% (4.2%non determined). 50.8% of patients had simple partial seizures, 84.3% complex partial and 59.3% secondary generalized seizures. A majority of patients (65%) had received 1 to 3 AEDs since disease onset. Amongst the patients who have completed at least the first 3-month treatment period (n=82), 73.2% were responders (of whom more than a half achieved a 75 % reduction in seizure rate from baseline), and 15.9 % remained seizure free since their last visit (i.e. between week 6 and month 3). A total of 17 (6%) of patients discontinued the study because of lack of efficacy (5), adverse event (9) or other reasons including non compliance(3). Most adverse events were CNS related.
CONCLUSIONS: These first results confirm that tiagabine is effective and well tolerated when given as add-on therapy in partial epilepsy. We expect that later results will provide valuable information to better address patients needs in daily practice.
Support: Sanofi-Synthelabo
Disclosure: Consulting - Sanofi-Synthelabo; Honoraria - Sanofi-Synthelabo