Ultra-short treatment courses tailored to a person's pre-treatment viral load deliver lower cure rates than 8-week treatment courses, but failure of ultra-short treatment does not prevent subsequent cure of hepatitis C with a second course of treatment, the STOPHCV1 study has found.
Shortening hepatitis C treatment courses may have advantages
for people who have adherence difficulties. There is some evidence that
treatment courses as short as four to six weeks may cure some people with
hepatitis C, but it is unclear what criteria should be used to select people
for shorter treatment courses.
Shorter-course treatment carries a higher potential risk of
failure, and it is unclear if this leads to resistance that compromises the effectiveness
of re-treatment.
To address these questions, the STOPHCV1 study investigated
whether people with mild liver disease could be cured of hepatitis C after four
to seven weeks of direct-acting antiviral treatment or successfully re-treated
if ultra-short course treatment failed.
Participants were randomised to receive either short-course
treatment, the duration determined by baseline viral load, or an 8-week course
of treatment. The regimen was chosen by the treating physician based on genotype
and local availability. Participants in both arms were also randomised to receive
ribavirin or no ribavirin. People who did not achieve a sustained virologic
response after the first treatment course received a second course of treatment
with 12 weeks of sofosbuvir/ledipasvir.
The study recruited participants with F0 or F1 fibrosis and
hepatitis C viral load below 10 million IU/ml at 14 hospitals in the United
Kingdom. The study recruited people with genotype 1a/1b/4 infection and people
co-infected with HIV were eligible to join the study. Recruitment took place between
May 2016 and May 2018.
The pre-specified duration of treatment based on baseline
viral load ranged from 28 days for viral loads of 50,000 IU/ml or below, to 49
days for viral loads above 8.8 million IU/ml. Fifty-eight per cent of the study
population randomised to short-course treatment were treated for between 28-34
days (4-5 weeks), 30% for 35-42 days (5-6 weeks) and 12% for 42-49 days (6-7
weeks). The duration of treatment based on viral load was increased on the
recommendation of the study’s Data Monitoring Committee halfway through the recruitment
period. This increased the treatment duration at all viral loads by three to
four days.
The study recruited 202 people with a median age of 45
years, 31% female, 34% co-infected with HIV and 32% current or recent illicit
substance users. The median baseline viral load was 711,423 IU/ml and 98% of
participants received a regimen of paritaprevir/ombitasvir/dasabuvir, the
preferred first-line regimen in the United Kingdom at the time the study took
place.
The primary outcome of the study was sustained virologic response
after ultra-short-course and re-treatment course. There was no significant
difference between study arms; all participants achieved a sustained virologic
response after first-line treatment and re-treatment apart from five participants
who were lost to follow-up.
After first-line treatment there was a significant difference
in outcome. Whereas 91% of those in the fixed-duration study arm achieved a
sustained virologic response, only 48% in the ultra-short course arm did so
(p<0.0001). After adjustment in the duration of treatment in the
ultra-short-course arm halfway through the study, sustained virologic response
rates improved significantly in this study arm, from 36% to 72% (p<0.0001).
Inclusion of ribavirin in the regimen did not significantly affect treatment
outcome.
In the first treatment course, five participants in the
fixed-duration arm and 16 in the ultra-short-course arm never achieved an undetectable
viral load. Six in the fixed-duration arm and 35 in the ultra-short course arm
experienced viral rebound after having an undetectable viral load.
Fourteen participants whose first-line treatment failed
developed resistance to at least one drug in their regimen. There was no
difference in resistance emergence after failure between study arms but people
who received ribavirin were significantly less likely to develop resistance
(p=0.01).
Serious adverse events occurred in 5% of study
participants and did not differ between study arms. Serious adverse events did
not occur more frequently in ribavirin recipients.
The study investigators conclude that “a high proportion of
patients can be cured with […] approximately 60% of the licensed duration of
first-line therapy of agents used in the trial.” But they also note that cure
rates with the ultra-short-course regimen were not high enough to justify using
it in people able to adhere to an 8-week treatment course.
They also say that the strategy needs to be tested using
pangenotypic regimens to assess whether failure of a first-line regimen that
does not contain a protease inhibitor permits successful re-treatment in all
cases.