Symdeko (tezacaftor/ivacaftor and ivacaftor), for the treatment of cystic fibrosis (CF), in people who are homozygous for the F508del mutation or possess one mutation in the cystic fibrosis transmembrance conductance regulator (CFTR), was approved by the Therapeutic Goods Administration (TGA) of Australia.
The missing or malfunctioning protein affects the movement of chloride, a component of salt, and water in and out of the body’s cells, causing a thick mucus to build up in a CF patient’s lungs or organs.
The treatment combines two CFTR modulators to work on the CFTR gene. According to a spokesperson for Vertex, Tezacaftor works to help move the CFTR protein to the cell surface and ivacaftor enables the protein to stay open longer once it reaches the cell surface.
The combination therapy increases the quantity and function of protein at the cell surface to help keep a balance of salt and water.
Approval for Symdeko comes after two pivotal Phase III studies showed treatment with tezacaftor/ivacaftor, in combination with ivacaftor, increased lung function.
Symdeko was approved by the US Food and Drug Administration (FDA) in February 2018, Health Canada in June 2018, and the European Commission in October 2018.
Vertex hedges bets on triple combination therapy
Vertex is exploring other gene therapy options for the treatment of CF, as it develops a triple-combination medicine that, according to a company spokesperson, “has the potential to eventually treat 90% of all people with CF.”
Still in development, the treatment is being tested with either one of the ‘next generation’ CFTR modulators, VX-445 and VX-659, in combination with tezacaftor and ivacaftor.
Treatments with VX-445 and VX-659, in combination with texacaftor and ivacaftor, are in Phase III testing. Vertex hopes to file a new drug application for the triple combination regimen with the strongest results no later than mid-2019.