
Full Answer
What is the success rate of DAA therapy?
The success of initial DAA therapy has led to treatment of hundreds of thousands of patients in the US. With this massive scale-up, there will inevitably be failures. Even with a 2% to 3% failure rate, there will still be thousands who need retreatment.
What should be monitored during DAA treatment for anemia?
All patients require careful monitoring during treatment, particularly for anemia if ribavirin is included in the regimen (See Monitoring section). The success of initial DAA therapy has led to treatment of hundreds of thousands of patients in the US. With this massive scale-up, there will inevitably be failures.
Does prior DAA exposure affect the selection of resistance-associated substitutes?
Prior DAA exposure may result in the selection of resistance-associated substitutions (RASs), particularly in NS5A, which could theoretically compromise the retreatment regimen.
What are the signs and symptoms of Doac treatment failure?
Each agent had different median failure times. Most common manifestations of treatment failure were stroke/transient ischemic attack (20.3%), pulmonary embolism (19.0%), and deep venous thrombosis (19.0%). More than half of patients were transitioned to a Vitamin-K antagonist after DOAC failure (55.7%).

What is the reason for virological failure?
Viral resistance is a major reason for virological failure to direct acting antiviral (DAA) treatment in patients with chronic hepatitis C virus (HCV) infection. However, importance mainly depends on DAA regimen and HCV genotype. For first-line therapy with Glecaprevir/Pibrentasvir (G/P) or Velpatasvir/Sofosbuvir (VEL/SOF) due to the high antiviral activity and high barrier to resistance no general baseline resistance analysis is required. If available, it may help to optimize therapy in certain subgroups of patients with HCV genotype 3 and other rare HCV geno/subtypes. For second-line treatment of DAA-failure patients Voxilaprevir/Velpatasvir/Sofosbuvir (VOX/VEL/SOF) as multiple targeted rescue therapy is the first choice with rates of viral eradication above 90% irrespective of the presence of resistance associated substitutions (RASs). However, in resource-limited settings only first generation DAAs may be available for second line therapy. Here, RASs selected during initial antiviral therapy should be considered if testing is available and rescue treatment should include a switch to a regimen with a new DAA-class to optimize treatment response. For both, VOX/VEL/SOF and rescue therapy with first generation DAAs patients with HCV genotype 3 are overrepresented in the group of treatment failures. Limited data are available for third-line therapies. Here, independent of RASs profiles treatment with G/P plus SOF or VOX/VEL/SOF with or without ribavirin for 12 to 24 weeks showed promising results and should be administered.
Is RAS detectable in DAA?
In the vast majority of patients with virologic failure to DAA regimens typically RASs are detectable within the target regions of applicated DAAs. From data of approval studies and from different publications of real word studies with larger cohorts of patients with virologic treatment failure to diverse interferon-free DAA regimens patterns of resistance to NS3, NS5A and NS5B inhibitors have been characterized ( Table 2) [ 16, 19, 25, 29, [33], [34], [35], [36], [37], [38] ].
How are recommended and alternative regimens listed?
Recommended and alternative regimens are listed in order of level of evidence. When several regimens are at the same recommendation level, they are listed in alphabetical order. Regimen choice should be determined based on patient-specific data, including drug interactions.
What is recommended regimen?
Recommended regimens are those that are favored for most patients in that group based on optimal efficacy, favorable tolerability and toxicity profiles, complex ity, and shorter treatment duration .
Is DAA therapy a failure?
The success of initial DAA therapy has led to treatment of hundreds of thousands of patients in the US. With this massive scale-up, there will inevitably be failures. Even with a 2% to 3% failure rate, there will still be thousands who need retreatment. Since the last iteration of this section, additional published evidence has emerged to support recommendations for retreatment. To simplify and consolidate the guidance, this section no longer contains retreatment recommendations for interferon or interferon plus first generation protease inhibitor failures because the cure rates with modern DAA regimens in these populations were comparable to treatment naive patients. In addition, pangenotypic regimens without the addition of ribavirin have shown high efficacy for patients with prior failure across all genotypes except genotype 3. Therefore, recommendations are categorized by regimen failure.
