Luxturna (voretigene neparvovec-rzyl) is currently the only approved gene therapy available in the US. It is the first medication approved for an inherited genetic disease ever. Luxturna was approved by the FDA at December 19, 2017 for the United States and it is currently under supervision at the EMA for approval in Europe. It is developed by Spark Therapeutics and outlicensed commercial rights outside the United States to Novartis.
Luxturna is used for patients with an inherited form of retinal dystrophy. Retinal dystrophy is an umbrella term for a wide range of progressive eye diseases. ‘Retinal’ means that the condition is related to the retina, which is the back layer of the eye which converts light into an understandable message to the brain. ‘Dystrophy’ is a degenerative condition. Retinal dystrophy causes progressive reduction or deterioration of vision which eventually can result in complete blindness. Luxturna can be used for patients who have mutations in the RPE65 gene in both chromosomes.
Luxturna is an adeno-associated virus type 2 (AAV2)-based treatment where the correct copy of the RPE65 gene is delivered without disturbing the genome. Luxturna is injected directly into the retina so it can infect the retinal cells. When RPE65 is expressed in those cells, it can perform its function and in principle, halt the progression of the disease.
Imlygic (talimogene laherparepvec) is a genetically modified herpes virus used to treat melanoma. Imlygic was approved by the FDA at October 27, 2015 and by the EMA at December 17, 2015. It was originally developed by BioVex and continued by Amgen after the acquisition of BioVex by Amgen in 2011. Although melanomas shrink due to Imygic, there is no statistically significant benefit in overall survival. In other words, Imlygic does not extend lifes of patients with melanoma. The lack of benefits in combination with the price tag of approximately $65,000 makes Imlygic unpopular to prescribe for doctors.
Imlygic is an oncolytic viral therapy with attenuated life herpes simplex virus type 1 (HSV-1). In HSV-1, two genes are removed and one gene is added. The genes who are removed originally code for the proteins infected cell protein 34.5 (ICP34.5) and infected cell protein 47 (ICP47). ICP34.5 blocks the response of healthy cells to stop replicating and die after viral infection. However, cancer cells lack this system. By removing ICP34.5, HSV-1 can not replicate and kill normal cells, but in cancer cells they can. ICP47 suppresses an immune response to viral infection. Removing ICP47 should trigger an immune response, in theory. A gene coding for granulocyte colony-stimulating factor (GM-CSF) is inserted to promote an immune response to cancer cells infected by Imlygic. Despite these efforts, clinical evidence for an immune response to cancer cells due to Imlygic is not available.
Note: this page is under construction. New gene and cell therapy products will be added soon.