CHICAGO -- An investigational drug combination was equally effective in all genotypes of hepatitis C (HCV), whether patients were treated for eight or 12 weeks, a researcher said here.
In a pooled analysis from seven randomized controlled trials, the combination of glecaprevir and pibrentasvir cured 97% of those treated for eight weeks and 98% of those treated for 12 weeks, according to Stuart Gordon, MD, of the Henry Ford Health System in Detroit.
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Cure rates were similar regardless of the genotype of the virus, Gordon said at .
The drugs -- glecaprevir is an NS3/4A inhibitor and pibrentasvir is an NS5A inhibitor -- formulated into a single pill, although patients must take three of them, once a day. The combination is currently under priority review by the FDA and undergoing accelerated review by the European Medicines Agency.
The combination has piqued interest both for its high efficacy rates and its ability to treat most patients without regard to the HCV subtype. At the recent in Amsterdam, researchers reported 99% cure rates among cirrhotic patients with all genotypes except 3 after 12 weeks of therapy. And earlier research suggested treatment for cirrhotic genotype 3 patients might take longer but would still lead to equivalent cure rates.
In the current analysis, Gordon reported that adverse events were few and mild, with only one event related to the study drugs among 1,193 patients in the intent-to-treat population. Four patients had breakthrough viremia while on treatment, 14 relapsed after the end of treatment, and 11 stopped therapy.
The remaining patients were cured, defined as HCV RNA below the lower limit of quantification 12 weeks after the end of therapy -- the so-called SVR12, Gordon said.
Importantly, there was little difference in cure rates based on duration of therapy, Gordon said, suggesting that -- at least in this population -- an eight-week course of medication will suffice.
Analysis showed that few patients had resistance mutations to either NS3 or NS5 at baseline and fewer than 1% had both NS3 and NS5 resistance -- the only factor that predicted treatment failure.
The bottom line is that that a short treatment course looks to be possible for just about every patient who hasn't developed cirrhosis, commented Richard Sterling, MD, of Virginia Commonwealth University in Richmond, Va., who was not part of the study but who moderated the session at which it was presented.
"We're getting to the eight-week regimens," Sterling told 51˶, although that's really an "incremental" improvement over the 12-week treatment courses that are now pretty much standard.
One advantage of the combination, he said, is that patients with HCV genotype 3 did well without the need to add ribavirin, as is sometimes the case with sofosbuvir/velpatasvir (Epclusa).
And because very few relapses were associated with resistance mutations in the virus, it might be possible to avoid resistance testing, which adds expense to the treatment, he said, as well as time if test samples have to be sent to an off-site lab.
The delay is not usually long, but "patients are anxious -- they want to get going," he said.
Disclosures
The study had support from AbbVie. Gordon disclosed relationships with the company, as well as Gilead, Intercept, CVS-Caremark, UpToDate, and Merck.
Sterling disclosed relationships with Salix, Bayer, ViiV, Baxter, Pfizer, AbbVie, Gilead, Merck, BMS, and Roche/Genentech.
Primary Source
Digestive Disease Week
Puoti M, et al "High SVR rates with eight and twelve weeks of pangenotypic glecaprevir/pibrentasvir: Integrated efficacy analysis of genotype 1-6 patients without cirrhosis" DDW 2017; abstract 429.