SAN FRANCISCO – Hepatitis C therapy has matured and now offers excellent sustained viral response (SVR) in the vast majority of cases, but key challenges remain in getting the therapy to those who need it.
“Unfortunately, we’re not making some of the progress we might have hoped to see, particularly in North America,” said Jordan Feld, MD, MPH, who gave a debrief of hepatitis C abstracts during a wrap-up session at the annual meeting of the American Association for the Study of Liver Diseases.
The problem is particularly acute in young adults aged 18-39 years – only about 9% of those who tested positive for HCV RNA saw a specialist, and about 23% of those who saw a specialist went on to receive treatment, according to an analysis of over 17 million patients in the United States (abstract 1567). The numbers were better for older adults but still far from optimal, with 23% who tested positive seeing a specialist, and just 32% of those patients getting treatment.
Another study (abstract 0147) looked state by state at the percentage of Medicaid patients who received a prescription for direct-acting antiviral (DAA) medication and then went on to fill the prescription. The rates ranged from 0% in Alaska to 96% in Connecticut. Eight states were higher than 70%, six were between 50% and 70%, and 15 states were below 50%.
“Despite our efforts, there continue to be major access barriers across the U.S., particularly for Medicaid individuals,” said Dr. Feld, who is a clinician-scientist at the Toronto Western Hospital Liver Clinic and the McLaughlin-Rotman Centre for Global Health.
A study examining the Chronic Hepatitis (CHeCS) cohort (abstract 0585) described a big spike in treatment uptake shortly after approvals of the new HCV regimens, but by 2016, only about one-third of individuals who required treatment actually began treatment. Factors associated with nontreatment largely reflected marginalization, including low income, being on Medicaid, and lack of long-term follow-up.
Even as health systems struggle to get treatment to those who need it, new studies are showing how to expand existing treatments into new populations.
Results from the EXPEDITION 8 study (abstract LB-7) showed efficacy of an 8-week regimen of the glecaprevir/pibrentasvir combination in patients with compensated cirrhosis. It looked at genotypes 1, 2, and 4-6. In an intention-to-treat analysis, 98% attained SVR and there were no viral failures or safety concerns. A follow-up trial is ongoing that includes patients with genotype 3. “This is exciting to be able to shorten therapy in patients with cirrhosis,” said Dr. Feld.
Although first-line DAAs are extremely effective, there are a few patients who do not achieve a cure. One study (abstract 0227) examined the combination of sofosbuvir, velpatasvir, and voxilaprevir in retreatment of these patients. The drugs resulted in SVR rates similar to those in registration trials, but the regimen was somewhat less effective in patients previously treated with sofosbuvir and velpatasvir. “I think we need to investigate that further,” said Dr. Feld.
The combination of glecaprevir and pibrentasvir also proved effective for retreatment in patients with genotype 1/1A who had failed treatment with an NS5A inhibitor plus sofosbuvir with or without ribavirin (abstract 226). SVR rates at 16 weeks were quite good, but lower in genotype 1a patients at 12 weeks (87% week 12 versus 94% week 16).”I think this is a really good regimen for genotype 1b. For 1a, serum definitely needs 16 weeks [to clear],” said Dr. Feld.
Other abstracts presented at the meeting detailed some of the benefits of SVR, not all of which are broadly appreciated. An analysis of the Hepatitis Testers Cohort in British Columbia (abstract 145), which includes over 7,000 patients who were followed for a median of 2 years (DAA) or 9.5 years (interferon-based), showed survival advantages to SVR in both cirrhotic (adjusted hazard ratio, 0.14) and noncirrhotic patients (aHR, 0.13). Other benefits include lower risk of diabetes (aHR, 0.53), chronic kidney disease/endstage renal disease (aHR, 0.48), stroke (aHR, 0.67), and mood and anxiety disorders (aHR, 0.53) (abstract 148).
As is generally accepted, SVR reduces the risk of hepatocellular cancer (HCC), according to analyses of VA and Gilead data (abstract 635), with a benefit in both cirrhotic and noncirrhotic patients. The risk almost disappears in patients without cirrhosis (incidence rate 0.07 per 100 person-years and is curbed in cirrhotic patients (incidence rate 1.30 in compensated, 4.05 in decompensated cirrhosis).
“There is really very significantly high incidence in cancer in decompensated cirrhosis, which just highlights that these patients continue to need ongoing surveillance. Although there have been efforts at developing strategies to risk stratify patients with cirrhosis, at least for now we’re stuck with surveillance, but I think for patients without cirrhosis there are now enough data showing a low enough incidence of primary HCC that we can probably avoid surveillance in that group,” said Dr. Feld.
Injectable drug users represent a special challenge in hepatitis C treatment, but new studies show cause for optimism in this population. These patients are harder to reach, and they may be less medication compliant, but one study (abstract 1632) found that imperfect adherence doesn’t necessarily undermine results – in a 12-week regimen, patients who didn’t finish until 14 weeks had no significant difference in SVR rates.
“So these therapies have a bit of forgiveness. We probably shouldn’t tell that to the patients, but it’s reassuring that we can use these therapies even in tough-to-reach populations,” said Dr. Feld.