A new treatment for hepatitis C "cured" 90% of patients with the infection in 12 weeks, scientists said.
The study is a "major breakthrough" and marks a "turning point" in hepatitis C treatment, said experts.
More than 200,000 people are infected with hepatitis in the UK, and deaths from the infection have increased threefold since 1996.
Only 3% of patients in the UK currently opt for the existing treatment, which only works half of the time.
'Excited for patients'
Hepatitis C is a virus that can infect and damage the liver.
It is passed on by the blood, or bodily fluids of an infected person, and can be transferred through tattoo needles, or people taking drugs and sharing needles.
Researchers at the University of Texas Health Science Centre tested the new oral drug in 380 patients at 78 centres in Spain, Germany, England and the US in 2013.
Two studies were carried out, one in patients for 12 weeks, and another, for 24 weeks.
The patients had liver cirrhosis, indicating an advanced form of the virus.
After 12 weeks, 191 of 208 patients no longer had hepatitis C, which increased to 165 of 172 patients, or 96%, after 24 weeks.
Lead researcher, Dr Fred Poordad said: "It is fantastic. I am so excited for the patients. There is finally hope for their future."
He said the drug worked by targeting the protein that makes hepatitis C and stopping it from replicating.
"Eventually the virus is extinguished," he said.
The study worked for patients with genotype 1 infections, which account for 45% of infections in the UK. The other 45% are a genotype 3. Genotype 2 is less common.
The side affects were fatigue, headaches and nausea.
Political will needed
Current treatment for hepatitis C can include a year's worth of injections and involve side-effects such as depression, tiredness and feeling sick. It also is not safe for many people with cirrhosis, said Dr Poordad.
Gkikas Magiorkinis, consultant physician in medical virology at the University of Oxford, said treating the patients with cirrhosis was a "major breakthrough".
Concerns over the high toxicity and low efficiency of current treatment had meant it was not widely been applied.
"It remains to evidence the benefit of the treatment in patients with advanced liver disease," Mr Magiorkinis said.
However the study did not show if the probability of cancer dropped in the long term, if cirrhosis was reversed or progression to total liver failure slowed.
Whether or not the treatment prevented further transmission in the public was also yet to be seen, he added.
Charles Gore, chief executive at the Hepatitis C Trust, said: "This is a turning point. I think it is incredibly exciting. We suddenly have the opportunity to eliminate the virus in the UK - even without a vaccine."
Mr Gore said whether or not the disease could be eliminated would be down to political will, which he said was lacking in the UK.
He said although the study involved genotype 1, treatments for genotypes 2 and 3 were "close behind", he said.
Mr Gore said treatment could reach the UK later this year.