The research team, led by Paul Kwo, M.D., of Indiana University School of Medicine, reported that adding the drug nearly doubled the treatment's effectiveness when given for 48 weeks in one treatment arm of the study.
An estimated 3.2 million Americans and 170 million people worldwide are infected with the hepatitis C virus, but many do not know it. In the United States, 70 percent of affected individuals are infected with genotype 1 hepatitis C, the most difficult to treat. Although there may be no symptoms for years, long-term infection can cause cirrhosis and the disease is a leading cause of liver cancer and liver transplantation. Hepatitis C infections occur mainly through transmission of infected blood, such as via injection drug use, and there is no vaccine.
Currently fewer than half of patients with genotype 1 hepatitis C are treated effectively by the standard combination of two drugs, peginterferon alfa-2b plus ribavirin, which is typically given for 48 weeks. The treatment can be difficult for some patients due to anemia and other side effects.
Adding the drug boceprevir increased the cure rate to as high as 75 percent in those who received 48 weeks of the three-drug combination therapy, compared to 38 percent of those in the control group, who received the standard two-drug treatment for 48 weeks, said Dr. Kwo, associate professor of medicine at the IU School of Medicine. The two-year phase 2 trial was conducted at 67 sites with 520 patients in the U.S., Canada and Europe.
In the boceprevir study, known as the SPRINT-1 trial, researchers tested several different options to evaluate the effectiveness of the combination therapy:
To test whether the addition of boceprevir could make it possible to shorten treatment times, some patients were randomly selected to receive the three-drug combination for 28 weeks, some for 48 weeks.
Researchers also investigated whether a 4 week lead-in with the standard two-drug combination prior to the addition of boceprevir to the treatment regime could improve sustained virologic response rates. The goal was to see if allowing the interferon and ribavirin to reach steady state levels -- which would activate the immune system and reduce virus levels -- before adding boceprevir would improve the response rates as well as reduce the virus' ability to develop resistance to boceprevir, said Kwo.In another arm of the trial, researchers tested whether a lower dose of ribavirin could reduce the anemia side effects while still treating the virus effectively.
Boceprevir, a product of Merck & Co., is an HCV protease inhibitor – a compound designed to block a function key to viral reproduction in the cell. Boceprevir directly targets the hepatitis C virus, Kwo noted, while peginterferon and ribavirin are less specific, acting more generally to stimulate the body's virus-fighting immune system.
The best results were reported for the 103 patients who were treated for four weeks with the standard two drug regiment, followed by 44 weeks of the three-drug regimen including boceprevir: 75 percent of these patients tested negative for evidence of the virus six months after the end of treatment. Results for the other treatment arms were:
67 percent of those who received the three drug regimen for 48 weeks with no lead-in treatment tested negative for the virus (103 patients).
56 percent of those who received the two-drug lead-in for four weeks, followed by 24 weeks of the three drug treatment tested negative for the virus (103 patients).
54 percent of those who received the three-drug treatment for 28 weeks with no lead-in tested negative for the virus (107 patients).
38 percent of the control group, who received the standard two-drug treatment for 48 weeks tested negative for the virus (104 patients).
Patients receiving the low-dose of ribavirin did not fare as well – just 36 percent were virus-free after 48 weeks of treatment.
"Based on this phase 2 study, it appears that if this drug receives final approval approximately two-thirds of patients will be able to be treated successfully with 28 weeks of treatment and one-third will need 48 weeks of treatment, though this will require confirmation from the phase 3 trials, from which preliminary results were recently released," said Dr. Kwo.
The research was funded by Schering Corp. a division of Merck & Co., which provided assistance with the trial, data collection and analysis, and the manuscript.
Eric Schoch | EurekAlert!
Hot cars can hit deadly temperatures in as little as one hour
24.05.2018 | Arizona State University
3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
24.05.2018 | Physics and Astronomy
24.05.2018 | Health and Medicine
24.05.2018 | Life Sciences