Individuals who have failed hepatitis C virus (HCV) treatment may ultimately achieve a cure if they add Sovaldi (sofosbuvir) to a subsequent treatment regimen, aidsmap reports. Researchers presented findings of two studies looking at such re-treatment strategies at the Annual Meeting of the American Association for the Study of Liver Diseases (AASLD) in San Francisco.

Merck’s C-SWIFT re-treatment study included 25 people who had relapsed after a previous hep C cure attempt with the NS5A inhibitor elbasvir and the protease inhibitor grazoprevir, given for four, six or eight weeks. Enrolled a median 214 days after virologic failure, they were re-treated for 12 weeks with the two Merck drugs, along with Gilead Sciences’ nucleotide analog polymerase inhibitor Sovaldi plus ribavirin.

Two participants were lost to follow-up during the first week of treatment. All of the remaining participants achieved a sustained virologic response 12 weeks after completing therapy (SVR12, considered a cure).

AbbVie’s QUARTZ-1 study included 22 participants who had experienced viral failure or relapse after a first treatment attempt with a variety of regimens. They were treated with Viekira Pak (ombitasvir/paritaprevir/ritonavir; dasabuvir) plus Sovaldi and ribavirin.  

Viekira Pak consists of two pills: a coformulated tablet including the NS5A inhibitor ombitasvir, the NS3/4A protease inhibitor paritaprevir, and the HIV protease inhibitor Norvir (ritonavir); and the non-nucleoside NS5B palm polymerase inhibitor dasabuvir.

Participants were treated for 12 weeks, unless they still had detectable hep C at week 12, in which case they were given the option of another 12 weeks of treatment.

Out of the 15 people treated for 12 weeks, 14 (93 percent) achieved a sustained virologic response 12 weeks after completing therapy (SVR12, considered a cure). One person, who had no evidence of hep C drug resistance upon starting the study, experienced virologic relapse.

All of those treated for 24 weeks have achieved a sustained virologic response four weeks after completing therapy. This is known an SVR4 and is a very good indicator that they will maintain an undetectable hep C viral load for another eight weeks to achieve an SVR12.

To read the aidsmap article, click here.