On-label use of a drug under patent has also been shown to be an effective strategy as demonstrated in the case of everolimus for the treatment of tuberous sclerosis. When in 1977, the Tuberous Sclerosis Association (TSA) was first formed, they strived to raise £30,000 for research into the mechanism behind tuberous sclerosis. Research demonstrated hyperactivity of the mTOR pathway and academics hypothesised that mTOR inhibitors might therefore be effective in the treatment of tuberous sclerosis. Following a small patient group- and government-funded trial showing positive results, the pharmaceutical company Novartis agreed to fund a large international phase III study using their existing drug, everolimus, which was under patent. The clinical trial results were positive and everolimus gained regulatory approval for SEGA (a type of brain tumour) and epilepsy associated with tuberous sclerosis. By developing the drug for a new disease, its market exclusivity was extended to 2021, and patients can now receive the treatment at a relatively low cost of around £36,000 per patient per year.