A combination of Gilead Sciences hepatitis C virus (HCV) drug Sovaldi with a new compound can provide high cure rates regardless of the strain of the virus infecting the patient.
The once-daily, fixed-dose combination of Sovaldi (sofosbuvir) with velpatasvir (GS-5816) – described as a ‘pan-genotypic’ NS5A inhibitor – could eliminate the need for HCV patients to have a genotyping test before starting treatment, said the company.
Four phase III trials of the drug (ASTRAL 1-4) have now been completed, spanning patients with HCV genotypes 1 to 6 and including some with established liver cirrhosis, and showed sustained virologic response (SVR) rates ranging from 80% to 100% after 12 weeks’ treatment.
Genotype 1 is the most common form worldwide, making up around half of the 185m cases – add in genotypes 2 and 3 and around 60% of HCV infections are accounted for. However, given the huge number of HCV cases the less common genotype infections still affect millions of people, often living in lower-income countries and these are much less served in terms of drug options.
Gilead is planning to file for approval of the new combination in the US and Europe before the end of the year, and is hoping for a rapid review as the drug has already been granted a ‘breakthrough’ designation by the FDA.
If approved, the new drug will join Sovaldi and Harvoni (sofosbuvir/ledipasvir), a product specifically indicated for patients with HCV genotype 1 infection, the Gilead’s HCV portfolio. The two products brought in sales of $2.26bn and $7.19bn respectively in the first six months of the year, well ahead of expectations and new rivals such as AbbVie’s Viekira Pak (ombitasvir/paritaprevir/ritonavir and dasabuvir) which turned over $616m in the same period.
“The ASTRAL study results demonstrate that a 12-week course of therapy with the first fixed-dose combination of two pan-genotypic compounds can provide high cure rates for patients with all HCV genotypes,” said Gilead’s chief scientific officer Norbert Bischofberger.
Gilead recently presented data on a triple combination of sofosbuvir, velpatasvir and pan-genotypic protease inhibitor GS which indicated that therapy could allow treatment duration to be reduced to six or eight weeks. The triple regimen is currently in two phase II studies.