High Hepatitis C Cure Rates With Harvoni and Viekira Pak in Veterans With Genotype 1

Hepatitis C (HCV) regimens containing ledipasvir/sofosbuvir (LDV/SOF, Harvoni) or paritaprevir/ritonavir/ombitasvir and dasabuvir (PrOD, Viekira Pak) yielded sustained virologic response (SVR) rates approaching those seen in clinical trials, according to an analysis of almost 17,500 patients in the Veterans Affairs (VA) health care system. The study also documented underuse of the cost-saving eight-week LDV/SOF regimen.

SVR rates with interferon-free direct-acting antiviral (DAA) regimens often exceed 95% in clinical trials. To determine whether the same rates can be reached in clinical practice and whether patients with HCV genotypes other than 1 respond well, VA researchers conducted this analysis of veterans taking SOF, LDV/SOF or PrOD with or without ribavirin (RIBA, Rebetol).

As the country's largest integrated health care system, the VA has 167 medical centers across the United States that care for 174,000 HCV-infected veterans. The study population included 2986 veterans taking SOF, 11,327 taking LDV/SOF and 3174 taking PrOD. The primary endpoint was the proportion of veterans with SVR 12 weeks after treatment ended (SVR12) according to regimen, HCV genotype and other subgroups.

Of the 17,487 veterans studied, 97%, were men, 52% were white, 29% black and 5% Hispanic. Age averaged 61 years. While 80% of participants had HCV genotype 1, 12% had genotype 2, 7% had genotype 3 and 1% had genotype 4. Nearly one-third of the veterans had cirrhosis, 8.3% had decompensated cirrhosis, 2.8% had hepatocellular carcinoma, 2.2% had undergone liver transplantation and 4.1% had HIV coinfection.

Overall SVR12 rates were 92.8% for genotype 1, 86.2% for genotype 2, 74.8% for genotype 3 and 89.6% for genotype 4. SVR12 was 92% or higher in genotype 1 patients regardless of DAA regimen. All veterans with genotype 2 received SOF + RIBA, which produced an SVR12 of 86.2%. SVR12 rates with genotype 3 infection were 77.9% with LDV/SOF + RIBA, 87% with SOF + RIBA + pegylated interferon and 70.6% with SOF + RIBA. With genotype 4 infection, SVR12s were 87.6% with LDV/SOF (with or without RIBA) and 96.4% with PrOD (with or without) RIBA.

Cirrhosis did not affect response rates with genotype 1 infection, but SVR12 was lower with than without cirrhosis for genotype 2 (77.3% versus 89.1%), genotype 3 (65.7% versus 81.6%) or genotype 4 (83.9% versus 91.5%). Treatment experience had no impact on SVR12 in genotype 1 veterans, but response rates were somewhat lower among treatment-experienced veterans with genotype 2 (80.2% versus 88.0%), genotype 3 (69.2% versus 77.5%) or genotype 4 (88.3% versus 93.5%).

Among treatment-naive, noncirrhotic, genotype 1 patients with a viral load below six million IU/mL who received LDV/SOF, SVR12 was similar with an eight-week course (95.1%, n = 1975) and a 12-week course (95.8%, n = 1556). The VA team noted that these findings confirm the effectiveness of eight-week LDV/SOF in appropriate patients with a consequently large potential cost savings.

Compared with veterans receiving PrOD, LDV/SOF recipients were more likely to have cirrhosis, decompensated cirrhosis, treatment experience and low platelets. But propensity score-adjusted models showed no significant difference in SVR12 with LDV/SOF versus PrOD.

Multivariable logistic regression analysis identified 10 independent predictors of failure to achieve SVR: genotype 2 or 3 (versus 1), treatment experience (in genotype 2 or 3 patients), male sex, black race, Hispanic ethnicity, diabetes, cirrhosis and decompensated cirrhosis, low platelet count, low serum albumin and elevated serum bilirubin.

Mark Mascolini writes about HIV and hepatitis virus infection.