In two new studies, researchers reveal that new drug regimens using direct-acting antiviral (DAA) agents could increase treatment uptake for hepatitis C, and even improve its effectiveness.
The disease can result in an acute form of the infection, where symptoms occur in the first 6 months after infection. Unfortunately, 55-85% of individuals infected with HCV go on to develop chronic infection, which can lead to liver diseases, such as cirrhosis or liver cancer.
According to the World Health Organization (WHO), 350-500,000 people die every year from hepatitis C-related liver diseases. In the US alone, the number of individuals who develop liver cancer or liver failure as a result of the infection is expected to treble by 2030, due to low treatment rates.
The researchers of these latest studies wanted to see whether they could develop a new drug regime that could improve treatment uptake. They focused on HCV genotype 1 - the most common type in the US, Europe, North Asia, Australia and South America.
Asunaprevir and daclatasvir regimen 'shows huge improvement on standard therapies'
The standard care for chronic HCV genotype 1 has been a combination of three antiviral medications; ribavirin (RBV), pegylated interferon (PEG) and a protease inhibitor. These three drugs work together to stop the virus replicating and help boost immune system response in order to eliminate the virus.
But although such treatment can be effective, its regimen can be hard to follow. Some patients are required to administer medication by injection as well as take up to 18 pills a day. This can continue for up to a year. In addition, the treatment can cause serious side effects, such as anemia and depression. All of these factors can deter patients from taking up the treatment.
In the first study - led by Prof. Michael Manns from Hannover Medical School in Germany - the team looked at the effectiveness of two direct-acting antiviral (DAA) agents - asunaprevir and daclatasvir - among 645 patients with HCV genotype 1b.
The patients were assigned to take each drug orally for 6 months. The researchers also assigned an additional 102 patients with the infection to receive placebos.
According to the team, the treatment was a success. They report that 90% of patients who were previously untreated, and 82% of patients who were unsuccessfully treated with standard regimens or who were intolerant of them, were cured of infection.
Commenting on their findings, Prof. Manns says:
"The efficacy and safety of 24 weeks of daclatasvir plus asunaprevir represents a huge improvement on the first generation of protease inhibitor-based triple therapies for HCV genotype 1b infection (up to 48 weeks of boceprevir or telaprevir in combination with PEG/RBV).
This new all-oral interferon- and ribavirin-free combination could provide a more effective, safer, shorter, and simpler treatment option for those traditionally hard-to-cure patients with cirrhosis or those who have failed to respond to existing therapies."
'93% of patients cured' by taking sofosbuvir and simeprevir without ribavirin
In the second study, led by Prof. Eric Lawitz of the Texas Liver Institute at the University of Texas Health Science Center, the research team included 167 patients who had either HCV genotype 1a or 1b.
Patients were randomly assigned to receive an oral combination of sofosbuvir and simeprevir once a day, with or without ribavirin, for either 12 or 24 weeks.
After 12 weeks, Prof. Lawitz and colleagues found 93% of patients who took sofosbuvir and simeprevir without ribavirin - including those with cirrhosis and those who were previously unresponsive to standard treatment - were cured of infection. No detectable HCV was found in their blood 3 months after treatment ceased.
Prof. Lawitz believes these findings show promise in new treatment options for patients with HCV genotype 1:
"We saw a cure rate of about 93% with only 12 weeks of treatment using an all-oral regimen that did not include interferon or ribavirin. This is especially encouraging given the high proportion of participants who had multiple characteristics traditionally associated with low cure rates, including cirrhosis."
In an editorial linked to the study, Prof. Ed Gane, director of the New Zealand Liver Transplant Unit at Aukland City Hospital, says that short-duration, all-oral DAA regimens should increase treatment uptake and improve their success, as well as reduce the burden of liver-related complications.
"When combined with targeted testing and treatment of populations who transmit infection (i.e., treatment as prevention), these DAA regimens might eventually eliminate HCV infection," he adds.
But he notes that there is a major hurdle to overcome before such treatment is widespread:
"The only barrier to achieving this goal will be the ability to access these new therapies. In many developing countries where HCV is endemic, interferon-based therapy will remain the first choice because of the high cost of DAAs and lack of reimbursement.
As almost 75% of all patients with HCV infection reside in economically deprived regions of eastern Europe, Asia, and the Middle East, consideration should be given to discounting prices in these regions. Eradication of HCV infection worldwide will only be achievable through universal access to HCV testing and new DAA regimens."
Earlier this year, Medical News Today reported on a study published in the New England Journal of Medicine, which also hailed the effectiveness of interferon-free therapy against hepatitis C. In this study, a combination of ABT-450/ritonavir, ombitasvir, dasabuvir and ribavirin was found to cure 90% of patients.
Written by Honor Whiteman