Comparative Effectiveness of Ledipasvir/Sofosbuvir ± Ribavirinvs. Ombitasvir/Paritaprevir/Ritonavir + Dasabuvir ± Ribavirin in 6961 Genotype 1 Patients Treated in Routine Medical Practice

L. I. Backus; P. S. Belperio; ; T. A. Shahoumian; T. P. Loomis; L. A. Mole

Disclosures

Aliment Pharmacol Ther. 2016;44(4):400-410. 

In This Article

Discussion

In this robust comparative effectiveness analysis of LDV/SOF ± RBV vs. OPrD ± RBV in genotype 1 HCV-infected veterans treated in routine medical practice, high SVR rates were achieved overall (86–95%) and within subgroups (83–100%). In multivariate models, OPrD + RBV was found to be less effective than LDV/SOF and patients receiving the former were 40% less likely to achieve SVR. However, in patients who completed a 12-week treatment course there was no difference in effectiveness. Similar to clinical trials, curative all-oral treatment has become a reality for over 90% of patients treated in the real-world, even in those with characteristics previously associated with poorer outcomes. This analysis demonstrates the real-world comparative effectiveness of all-oral DAA regimens in individuals with genotype 1 HCV infection that clinicians, patients and payers have anticipated.

The current HCV treatment landscape remains complex despite increasingly more effective HCV regimens, with variability in outcomes for patients with previous treatment experience, genotype subtype, race, degree of underlying liver disease and other comorbid conditions.[7,8,13,14,22–24] Because of the large sample size in this cohort, we were able to do robust subgroup analyses to examine differences among these characteristics and identify where challenges remain.

Despite SVR rates higher than any previously reported among veterans with advanced liver disease, the presence of advanced liver disease as indicated by a FIB-4 score greater than 3.25 remained a significant negative predictor of response with an apparent impact for treatment naïve and treatment experienced patients and across all regimens.[5,23,25] Over 2000 patients with advanced liver disease were included in this cohort. In multivariate models, the presence of advanced liver disease predicted reduced odds of achieving SVR by 40% independent of treatment experience and regimen. Absolute SVR rates in treatment naïve patients were generally four to five percent lower in those with advanced liver disease compared to those without advanced liver disease for patients who received LDV/SOF (87.6% vs. 92.6%), who received LDV/SOF + RBV (90.0% vs. 94.7%), and who received OPrD (91.7% vs. 96.1%). Current AASLD/IDSA treatment guidelines and FDA labelling recommend LDV/SOF for 12 weeks in treatment naïve patients with cirrhosis based largely on data from 34 patients in the ION-1 trial.[7,26,27] However, our observation of SVR rate of 87.6% with LDV/SOF in 889 treatment naïve patients with FIB4 scores >3.25 indicate SVR rates with this regimen may be below the 90% bar for which all-oral regimen expectations have been set and other treatment options might need to be considered in such patients.

In treatment experienced patients with and without advanced liver disease, reductions of 5–8% in SVR rates were seen in patients who received LDV/SOF (85.5% vs. 93.5%), who received LDV/SOF + RBV (85.4% vs. 90.9%), and who received OPrD + RBV (82.1% vs. 89.6%). The reduced SVR rates in the low to mid-80s in treatment experienced patients with advanced liver disease in this study mirror the 86% and 82% SVR rates observed in ION-2 in treatment-experienced cirrhotic patients receiving 12 weeks of LDV/SOF and LDV/SOF + RBV respectively.[8] In the TURQUOISE-II study SVR rates were 87% and 95% in treatment experienced cirrhotic null responders treated for 12 and 24 weeks respectively with OPrD+RBV.[14] The large number of patients included in our study coupled with the similar results obtained from ION-2 and TURQUOISE-II suggest that lower SVR rates may be expected in cirrhotic patients and particularly treatment-experienced cirrhotic patients treated in routine clinical practice. Extended treatment of 24 weeks in such patients may be warranted to achieve higher SVR rates.

In this cohort, SVR data were available for over 2300 African Americans. Multivariate modelling indicated African American race was associated with a 29% reduction in the odds of SVR. This effect was observed in multivariate models of the overall cohort but not in models limited to patients completing a 12 week treatment course suggesting that the reduced odds of SVR for African Americans arose in large part from excess early treatment discontinuations and from diminished effectiveness of 8-week LDV/SOF in African Americans, which has also been observed in retrospective analyses of the ION clinical trials.[22] Numerically lower SVR rates were observed in African Americans compared to Caucasians treated with LDV/SOF, OPrD and OPrD+RBV. In patients who received a full 12 weeks of treatment, SVR rates in African Americans were higher than in the intention-to-treat analysis and the numeric differences in SVR rates between African Americans and Caucasians were diminished.

This study included over 2300 patients with a BMI at or above 30 kg/m2, and in the overall cohort those with high BMI were 27% less likely to achieve SVR. As one might expect, the effect of BMI on SVR was not dependent on whether the patient completed therapy and, as such, high BMI remained a negative predictor of response in those who completed a 12-week treatment course. For such patients, additional treatment options may need to be considered to optimise SVR rates.

Shorter 8 week regimens were widely used in treatment-naïve patients with baseline HCV RNA below 6 000 000 IU/mL without cirrhosis. We could only assess the use of 8 week LDV/SOF regimens in patients who completed therapy because we were unable to otherwise determine if the original provider intent was to treat for 8 or 12 weeks using the available electronic data. Although the difference in SVR rates between those who completed 8 weeks and those who completed 12 weeks was numerically small at 3.4% it was statistically significant suggesting that to optimise a patient's likelihood of SVR the 12-week duration may be preferred.

Real-world SVR rates achieved with these treatment regimens were remarkably high. The large differences between real-world effectiveness and clinical trial efficacy previously observed with HCV antiviral treatment have now been almost eliminated with the use of potent all-oral regimens. Most of the small decrement in observed effectiveness in this real-world cohort may be explained in large part by higher early discontinuation rates. Early discontinuations rates were highest in those receiving OPrD + RBV (15.2%), followed by OPrD (11.4%), LDV/SOF + RBV (8.1%) and LDV/SOF (5.3%). Clinical trials tend to have early discontinuation rates of less than 3%.[7–14] Higher early discontinuation rates had the greatest impact on SVR rates in those receiving OPrD + RBV with a nearly 10% difference in SVR rates comparing intention-to-treat (85.8%) to those who completed 12 weeks (95.5%). While we did not examine reasons for early discontinuation, adverse effects and adherence are often recognised as contributing factors. Setting appropriate expectations about potential medication side effects and continued emphasis on adherence and persistence will remain important elements in maximising treatment success. Any remaining decrement in clinical effectiveness compared to clinical trial efficacy may be explained by differences in patient populations. For example, higher BMI in our cohort was identified as a significant negative predictor of SVR.

Given the high SVR rates achieved in clinical practice even among subgroups, regimen selection will depend increasingly upon nuanced considerations. Genotype subtype, presence of cirrhosis, prior treatment regimen or presence of pre-existing resistance associated polymorphisms currently determines the need for RBV and subsequent length of treatment for certain regimens. Potential for drug interactions and comorbidities may limit use of a particular agent. Enough options presently exist to allow providers some flexibility in selecting regimens tailored to meet individual patient characteristics or needs without sacrificing effectiveness. Expectations for high SVRs have been set and now validated in real-world cohorts, thus regimen subtleties together with cost considerations and insurance coverage will be key determinants for utilisation.

While this study includes one of the largest cohorts of diverse HCV-infected patients treated in clinical practice published to date, there are limitations. Specific reasons for early discontinuation (i.e. adverse events, poor tolerability, social or behavioural issues) could not be determined from the electronic data. Duration of treatment and early treatment discontinuation rates were determined based on the cumulative dispensed days' supply which may overestimate the treatment duration as patients may have discontinued treatment even with medication in their possession. In VA, many prescriptions are filled for small quantities (e.g. 2-week supplies) which would limit the extent of the overestimation. Baseline resistance testing was not performed thus we were unable to assess the impact of this factor.

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