Novartis’ Afinitor has significantly reduced treatment-resistant seizures in patients with tuberous sclerosis complex (TSC) taking part in the Phase III EXIST-3 trial.

TSC is a rare genetic disorder affecting up to one million people worldwide, and Afinitor (everolimus) is the only approved non-surgical option indicated for treating non-cancerous brain and kidney tumours in certain patients with the condition.

Epilepsy is the key symptom of the TSC, occurring in around 80-90% of patients, and represents a significant cause of morbidity and mortality. However, nearly two-thirds do not achieve seizure control with available therapies, “and may also experience other potentially serious consequences, such as neuropsychological, cognitive, social or learning disabilities,” said Jacqueline French, department of neurology, NYU Langone Medical Center, and lead investigator of the EXIST-3 trial, highlighting the unmet need.

The study found that the percentage reduction from baseline in seizure frequency was significantly greater among patients randomised to receive Afinitor (everolimus) in the low exposure arm (LE; 29.3 percent) and high exposure arm (HE; 39.6 percent) compared to placebo (14.9 percent). 

Seizure response rate (>=50 percent reduction) was also significantly greater with Afinitor LE (28.2 percent and HE (40 percent) vs placebo (15.1 percent), Novartis said.

The most common adverse events reported in those taking Afinitor LE/HE vs placebo included stomatitis (28.2 percent/30.8 percent vs 3.4 percent), mouth ulceration (23.9 percent/21.5 percent vs 4.2 percent), and diarrhoea (17.1 percent/21.5 percent vs 5.0 percent). Serious AEs reported were 13.7 percent/13.8 percent vs 2.5 percent, respectively.

"These findings are encouraging as this is the first clinical study demonstrating benefit specifically for TSC patients who suffer from treatment-resistant seizures,” Dr French noted.