New hope in hepatitis C treatment
Tuesday 5th November 2013, 2:50PM GMT.
A pill containing two anti-viral drugs appears to cure currently untreatable hepatitis C, offering new hope to patients at risk of serious liver damage and early death.
Although more work needs to be done to ensure the treatment is safe and effective, experts believe the early results could mark a turning point in tackling an intractable deadly disease.
In an early trial, the virus was eliminated from virtually every patient who took part, including those who had previously not responded to existing drugs.
Hepatitis C is a virus spread via blood and bodily fluids that damages the liver and often takes many years to produce symptoms. There is no vaccine that can prevent the infection, as there is for other forms of hepatitis.
Available treatments for hepatitis C consist of cocktails of powerful interferon and protease inhibitor drugs that have serious side effects and involve complex regimes of pills and injections.
But in a significant number of cases involving the common genotype 1 strain of the virus, the drugs will not work. Patients whose infections cannot be cured may suffer potentially fatal cirrhosis damage to their livers or develop liver cancer.
The new treatment consists of a single pill containing the experimental drugs sofosbuvir and ledipasvir.
For the trial, 100 patients with genotype 1 hepatitis C were split into different groups and given the combination pill for either eight or 12 weeks.
One group of 40 had previously failed to respond to existing drugs, and just over half of them had cirrhotic livers.
Three months after completing the course of treatment, 97% of the patients had achieved a sustained virological response (SRV) – essentially a functional cure that means the virus is eliminated and prevented from replicating.
The best responses were seen when the new pill was taken alongside the antiviral drug ribavirin, which is already commonly used to treat hepatitis C.
Patients who had failed to respond to other treatments reacted as well or better than those who had previously been treated successfully, or not been treated before.
Professor Eric Lawitz, from the University of Texas, who led the study reported online in The Lancet medical journal, said: “To our knowledge, this trial is the first to report data for cirrhotic genotype 1 hepatitis C patients who did not respond to prior treatment with a protease inhibitor regimen, a population without treatment options at present.
“The results of this trial suggest that the fixed-dose combination of sofosbuvir and ledipasvir could offer patients a short, all-oral treatment that might be highly effective and safe in patients who tend not to respond well to existing therapies, including individuals with cirrhosis, or black race, resistant strains of the virus, and those who have not responded to standard-of-care regimens that include protease inhibitors.”
Side effects included nausia, anaemia, respiratory tract infection and headache, but were not considered serious.
Just under half the patients in the study experienced at least one adverse event, with the highest rates observed in the groups receiving ribavirin. No patient in any group discontinued treatment because of side effects.
Professor Margaret Hellard, from the Burnet Institute in Melbourne, Australia, who co-authored a linked comment on the research published in The Lancet, said: “As a proof of concept study, (this) demonstrates very high response rates, regardless of the presence of cirrhosis, prior treatment failure, or (resistant) genotype.
“However, this was a small, single-centre study with only short follow-up, raising concerns about the representativeness of the sample and whether early clinical trial results can be easily generalised to real-world settings. Whilst giving cause for optimism, the full implications of these results need to be tempered for now.”
An estimated 255,000 people in England have hepatitis C. In 2010, a total 7,834 new cases were reported in England, though the true figure is probably much higher. Rates of hepatitis C infection are greater in people of African descent than other ethnic groups.
The virus is present in the blood and, to a much lesser extent, the saliva and semen or vaginal fluid of an infected person.
It is most likely to be transmitted through blood-to-blood contact. Injecting drug users who share their needles are known to be especially vulnerable.
Charles Gore, chief executive of The Hepatitis C Trust, said: “This new drug combination is fantastic news.
“We were concerned that those with advanced hepatitis C would remain difficult to treat, but these new direct anti-virals are incredibly potent.
“The results suggest that even the most difficult to treat people will in fact be extremely treatable.
“It now looks as if almost no one will be excluded from benefiting from treatment, which is an incredible achievement.”
Just under half of infected people in England have the genotype 1 strain of hepatitis C that can be resistant to treatment.
By 2015, infections by this strain are expected to result in 9,550 cases of cirrhosis in England.