Abstracts

In the US, LAMICTAL^[reg] (lamotrigine, LTG) is indicated for partial seizures with or without secondarily generalization in children and adults, and for the generalized seizures associated with Lennox-Gastaut syndrome. This abstract reports efficacy, including time to onset, and tolerability results from a study with LTG as adjunctive therapy in patients with primary generalized tonic-clonic seizures (PGTCS). LTG-na[iuml]ve patients ([ge] 2 years, [ge] 13 kg) with inadequately controlled PGTCS, receiving a stable regimen of 1 or 2 AED(s) and an electroencephalogram (EEG) with evidence of generalized epileptiform discharges or no evidence of interictal expression of partial seizures were enrolled in a randomized, double-blind, placebo-controlled, parallel-group trial. Patients having [ge] 3 PGTCS over an 8-week Baseline were randomized (1:1) to receive either LTG or placebo (PBO). The treatment period consisted of an Escalation phase (12 weeks for patients 2-12 years, 7 weeks for patients [gt] 12 years) and a Maintenance phase (12 weeks). Of 184 patients enrolled, 117 were randomized and received LTG or PBO. LTG group: n=58, 50% male, median age=27 years (range=2-53), 50% with 1 concurrent AED, most common concurrent AED: valproate=41%, phenytoin=31%, topiramate=21%, median PGTCS during Baseline=2.4. PBO group: n=59, 56% male, median age=25 years (range=2-55), 59% with 1 concurrent AED, most common concurrent AED: valproate=47%, phenytoin=22%, topiramate=12%, median PGTCS during Baseline=2.9. In the overall population the median percent decreases from Baseline in PGTCS were 56% and 30% (p=0.036) 5 weeks after treatment initiation with LTG and PBO, respectively; in patients [gt]12 years, the decreases were 63% and 33% (p=0.045) 3 weeks after treatment initiation. The median percent decreases from Baseline in PGTCS were 82% and 43% (p=0.006) during Maintenance, and 66% and 34% (p=0.006) during the entire treatment phase, for LTG and PBO, respectively. The median PGTCS counts per month were 2.4 and 2.9 during Baseline for LTG and PBO, respectively, 1.0 and 2.3 (p=0.013) during Escalation, and 0.4 and 1.6 (p=0.001) during Maintenance, and 0.8 and 2.0 (p=0.003) during the entire treatment phase. The most common ([ge] 5%) drug-related adverse events for LTG and PBO respectively were dizziness: 5% and 2% for LTG and PBO respectively, somnolence: 5% and 2%, and nausea: 5% and 3%. The non-serious rash rate was 3% for both LTG and PBO. No serious rash was reported. The results from this study, combined with the established efficacy and safety of LTG for partial seizures, clearly demonstrate that LTG is a broad spectrum AED which is efficacious and well tolerated in patients with either partial or generalized seizures. (Supported by GlaxoSmithKline.)