In this section we will cover:
- Example of a generic drug repurposed for off label use: ALPS and sirolimus
- Example of a patented drug repurposed for on label use: Tuberous sclerosis and everolimus
Example of a generic drug repurposed for off label use: ALPS and sirolimus
A successful example of a generic drug repurposed for off-label use is sirolimus, for the treatment of autoimmune lymphoproliferative syndrome (ALPS). In 2004, Cures Within Reach funded a single researcher to run a study of repurposed drugs in an ALPS mouse model, which in less than 36 months demonstrated potential efficacy of sirolimus, a generic transplant drug. The charity then provided further support for a pilot study in six patients, five of which were in complete remission after 90 days. Results were published open access to promote off-label use and monitoring of the treatment is ongoing in the literature. Cures Within Reach estimate that use of sirolimus saves $50,000 per patient per year and hugely improves their health and quality of life. Based on this success, Cures Within Reach have funded follow-on research to repurpose the same drug in five additional autoimmune diseases with remission seen in the majority of patients. For more information on the repurposing of sirolimus for ALPS, visit Cures Within Reach’s website here
Example of a patented drug repurposed for on label use: Tuberous sclerosis and everolimus
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.