Experimental Hepatitis C Drug May Treat the Untreatable
The pill combines two investigational drugs, sofosbuvir and ledipasvir, and in clinical trials it eliminated the hepatitis C virus (HCV) in nearly all patients who took it, according to findings published online Nov. 5 in The Lancet.
"Ninety-five percent of patients new to hepatitis C virus therapy who took eight weeks of the sofosbuvir/ledipasvir combination tablet were HCV undetectable 24 weeks after therapy ended, which means they are cured of HCV," said lead author Dr. Eric Lawitz, clinical professor of medicine at the University of Texas Health Science Center at San Antonio. "Similarly, among patients who had received prior therapy and took 12 weeks of sofosbuvir/ledipasvir, 95 percent were cured."
Hepatitis C, if left untreated, can cause severe and potentially fatal liver damage. However, most people recently infected with hepatitis C do not have symptoms. Instead, the virus causes long-term damage, mainly scarring of the liver, a condition called cirrhosis.
Combination drug treatments currently are available for the most prevalent form of the virus, which affects about 75 percent of Americans with the disease, Lawitz said. But these combination treatments involve interferon and protease inhibitors, which can have terrible side effects. The therapy also requires a complicated drug regimen of pills and injections.
Fewer than half of hepatitis C patients can undergo the existing combination therapy, given the drugs' interactions and side effects, the authors said in background information. For those patients, there are no treatment options at present.
"We've had nothing to offer them," said Dr. David Bernstein, chief of the division of hepatology at North Shore University Hospital in Manhasset, N.Y. "It's painted a rather bleak picture for these patients."
Sofosbuvir and ledipasvir are targeted, direct-acting agents that interfere directly with the life cycle of the hepatitis C virus, Lawitz said.
Researchers combined the two drugs into a single tablet taken once a day. They recruited 100 hepatitis C patients to try the medication, including 60 who had never received treatment and 40 who had been unsuccessfully treated using the current therapy. Some patients also received ribavirin, currently a standard treatment, in addition to the combination pill.
Just over half of the previously treated patients had cirrhosis.
By 12 weeks, nearly all of the patients had achieved what doctors call a sustained virological response, in which the virus is eliminated and prevented from replicating -- in essence, a functional cure.
"These types of advances are game-changers," Bernstein said. "We're going to be curing [very high percentages of people] with simple oral agents, one pill once a day with mild to no side effects."
About half of the patients had at least one health problem during the study, with the highest rates seen among patients who took ribavirin. The most common side effects were nausea, anemia, upper respiratory tract infection and headache. The treating physician rated most of them as mild, and no one had to discontinue treatment because of side effects.
The treatment of hepatitis C is rapidly changing, Lawitz said. "We are moving from an era of injectable medications with significant toxicity to an era of all-oral combination pill therapy that provides the promise of being well-tolerated with very high rates of cure," he said.
The combination drug is still being evaluated in phase 3 clinical studies, so it is too soon to tell if it will receive U.S. Food and Drug Administration approval or how it would be priced, Lawitz said.
Because hepatitis C progresses without symptoms, the U.S. Centers for Disease Control and Prevention recommends that adults born from 1945 through 1965 get tested for the virus.
For more information on hepatitis C, visit the U.S. National Library of Medicine.