This page shows what was measured, who it was measured in, and what that does not settle.
What Grazoprevir Anhydrous does in the body
Blocking those scissors also restores part of the cell’s own alarm system, which the virus normally disables.
Hepatitis C builds all its proteins as one long strip and then cuts the strip into working parts with its own molecular scissors. Grazoprevir jams the scissors, so the strip is never cut and the virus cannot assemble the machinery it needs to copy itself. It is given fixed together with elbasvir, which blocks a second, unrelated viral protein, so escaping one is not enough.
Why people take it. Long-standing hepatitis C infection in two genetic forms.
What happened in people
Combined with elbasvir, it cured about 95 to 99 in 100 across major studied groups.
✓ Reviewed first-read answer
Where this came from
A person wrote this and a reviewer approved it against this exact record. It carries no effect size.
A reviewer approved this against this record. The reviewed-claim record carrying the exact population and effect size does not exist yet.
No source is stored against this line.
The limit that matters most
Laboratory potency numbers were far stronger than the amount needed inside living cells.
Where it acts
Hepatocyte cytoplasm at the endoplasmic reticulum membrane — and the drug is actively pumped into the liver, which is why liver failure makes it dangerous and kidney failure does not
Kind of result
The kind of result is not recorded
Supervision
RNAWiki has not recorded a supervision or regulatory status for this substance.
What the registries record it as
The substance registry classes this as chemical.
FDA substance registry · 4O2AB118LA · read 2026-08-29
Where each sentence above came from
A person wrote this explanation into the record, with the studies named in the path below.
A reviewer approved this sentence against this exact record and its sources.
The limit a reviewer approved as the one that matters most here.
The four opening statements run to 105 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Comparator
A comparator is whatever the treatment was measured against.
A picture of it, and where the picture fails
It is like the other runner in a race.
Where that stops being true. A race has one winner. A study can show both arms improved.
What people get wrong. Results are read without asking what the other group got. Beating nothing is not beating a treatment.
The control condition against which the experimental intervention is assessed.
Randomisation
Randomisation means chance decides who gets which treatment.
A picture of it, and where the picture fails
It is like a coin toss deciding the groups.
Where that stops being true. A coin toss is fair once. Fairness here comes from doing it for everyone.
What people get wrong. It is thought to make groups identical. It makes them similar on average, including on things nobody measured.
Allocation of participants to arms by a chance process, so that unmeasured factors are balanced in expectation.
Absolute difference
An absolute difference is how many more people in a hundred were affected.
A picture of it, and where the picture fails
It is like counting heads in two rooms of a hundred.
Where that stops being true. Heads are easy to count. Study results carry a margin of error too.
What people get wrong. It is confused with a percentage change, which can look far larger.
The arithmetic difference in event rates between arms.
Confidence interval
A confidence interval is the range the true answer is likely to sit in.
A picture of it, and where the picture fails
It is like a weather forecast giving a range rather than one number.
Where that stops being true. A forecast range covers tomorrow. This one covers what the study could resolve.
What people get wrong. The middle number is read as the answer. A range crossing zero means no change is still possible.
An interval estimate that would contain the true parameter in a stated proportion of repeated studies.
What happened in people◇Read from sources, not yet reviewed
What happened in people
Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.
Unquantifiable HCV RNA 12 weeks after the end of treatment in the immediate-treatment group
✓ The study showed what it set out to show
Who was studied
C-EDGE TREATMENT-NAIVE (NCT02105467)
How many people
421
Study design
Phase 3, randomised 3:1 to immediate or deferred therapy, blinded, placebo-controlled
Compared against
A dummy treatment
Kind of result
A number that stands in for health
What was found
95% (299/316; 95% CI 92 to 97); serious adverse events 2.8% on active treatment against 2.9% on placebo
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. The authors list the absence of an active comparator and the small number of genotype 4 and 6 patients as limitations; genotype 6 SVR12 was 80% (8/10).
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral fixed-dose combination tablet with elbasvir
Interval reported. 95% CI 92 to 97); serious adverse events 2
Written into the record, not signed off as a reviewed claim.
96% (210/218; 95% CI 92.9 to 98.4), with all 35 cirrhotic patients cured
Repeated elsewhere
Unreplicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Single-arm with no comparator of any kind. Two of the seven relapses were later confirmed as reinfections, so the true virologic failure count is five rather than seven. Two patients on antiretroviral therapy had transient HIV viraemia.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral fixed-dose combination tablet with elbasvir
Interval reported. 95% CI 92
Written into the record, not signed off as a reviewed claim.
Sustained virologic response 12 weeks after treatment in genotype 1 with stage 4 or 5 chronic kidney disease
✓ The study showed what it set out to show
Who was studied
C-SURFER (NCT02092350)
How many people
235
Study design
Phase 3, randomised for safety against deferred treatment, observational for efficacy against a historical control
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
99% (115/116; 95% CI 95.3 to 100.0) against a historical control of 45% from interferon-based meta-analyses
Repeated elsewhere
Unreplicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. The efficacy comparison was explicitly non-randomised; the placebo randomisation served the safety endpoint. Five patients (4%) in the deferred group discontinued for an adverse event against none in the treated group.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral fixed-dose combination tablet with elbasvir
Interval reported. 95% CI 95
Written into the record, not signed off as a reviewed claim.
RNAWiki holds 3 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What it changes in the body◇Read from sources, not yet reviewed
The path through the body
From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.
Start
Grazoprevir Anhydrous
What a person takes: Oral fixed-dose combination tablet with elbasvir.
The measurement behind this step
One tablet once daily, with or without food, for 12 or 16 weeks depending on genotype, prior treatment and the baseline NS5A resistance test in genotype 1a. Grazoprevir is not sold separately.
Getting in
One tablet a day, after two pre-treatment tests
Everyone is tested for hepatitis B and has liver enzymes checked before the first dose, and the enzymes are checked again at week 8.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
Fixed-dose combination of 100 mg grazoprevir with 50 mg elbasvir, one tablet once daily with or without food. Apparent terminal half-life is approximately 31 hours for grazoprevir and 24 hours for elbasvir in infected subjects.
Grazoprevir does not simply diffuse into the liver. A transporter on the liver-cell surface pulls it in, which concentrates it exactly where the virus is.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Distributes predominantly to the liver, facilitated by active transport through the OATP1B1/3 uptake transporter. More than 90% of a radiolabelled dose is recovered in faeces and less than 1% in urine. Apparent volume of distribution approximately 1,250 L.
It jams the viral scissors, and unlike its predecessors Q80K does not save the virus
The virus makes all its proteins as one strip that must be cut apart. Grazoprevir sits in the cutting groove. The common natural variant that defeated the earlier drugs of this class does not affect it.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
A P2-to-P4 macrocyclic acylsulfonamide binding the NS3/4A active site, with biochemical IC50 of 7 pM (genotype 1a), 4 pM (1b) and 62 pM (4a), and replicon EC50 of 0.4, 0.5 and 0.3 nM. V36L/M, Q80K/R and V107I have no effect in cell culture.
The polyprotein is never cut, and the cell’s alarm comes back on
None of the individual viral proteins are released, so the copying machinery is never assembled. Blocking the same enzyme also restores part of the cell’s own antiviral alarm, which the virus normally disables.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
NS3/4A cleaves the polyprotein at the NS3-NS4A, NS4A-NS4B, NS4B-NS5A and NS5A-NS5B junctions, and also cleaves the host adaptor MAVS, blunting RIG-I-mediated interferon induction. Protease inhibition removes both the maturation step and the virus’s suppression of innate sensing.
Cured in twelve weeks, including with HIV and on dialysis
Ninety-five per cent of previously untreated patients, ninety-six per cent of those also living with HIV, and ninety-nine per cent of those with failing kidneys.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
SVR12 95% (299/316) in C-EDGE TREATMENT-NAIVE, 96% (210/218) in C-EDGE CO-INFECTION with all 35 cirrhotic patients cured, and 99% (115/116) in C-SURFER in stage 4 or 5 chronic kidney disease.
The limit is the liver, and it is the same property that helps the kidneys
Because the drug leaves only through the liver, a badly damaged liver lets it build up — twelvefold in the most severe cases. It is contraindicated there, and it is precisely that route of exit which makes it safe in kidney failure.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
Contraindicated in Child-Pugh B and C and in any history of hepatic decompensation, with a twelvefold exposure increase measured in Child-Pugh C subjects. Also contraindicated with OATP1B1/3 inhibitors, strong CYP3A inducers and efavirenz. ALT rose above five times the upper limit of normal in 1% of subjects, generally at or after week 8.
No suggested links are held for this record, so nothing is hidden from this path.
What we know
The record describes 6 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
Adults and children aged 12 and over with genotype 1 or 4, including those with HIV co-infection and those with advanced kidney disease. Contraindicated in anyone with moderate or severe liver impairment or any history of hepatic decompensation.
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
Where the result stopped carrying
Contraindicated in Child-Pugh B and C and in any history of hepatic decompensation, with postmarketing cases of decompensation and failure in advanced liver disease
ALT rose from normal to more than five times the upper limit in 1% of subjects, generally at or after week 8, requiring scheduled liver testing during treatment
D168A and D168V cost 110- to 320-fold in genotype 4, and A156 substitutions up to 375-fold in genotype 1b
Outright contraindicated with OATP1B1/3 inhibitors, strong CYP3A inducers and efavirenz
Two genotypes out of six, and displaced for most patients by pan-genotypic regimens within eighteen months
This is a scope explorer, not a diagnosis engine.
It shows who was studied so you can see whether people similar to you were included.
RNAWiki cannot tell whether a study fits you. It can show who was in it.
What it would be like to take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (11)
It was studied for a different goal
The studies measured something else entirely. Nothing in this record points to this reason.
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Prescription only
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Oral fixed-dose combination tablet with elbasvir
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form and route recorded on this substance.
No source is stored against this line.
Who oversees it
RNAWiki has not recorded a supervision or regulatory status for this substance.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
No register row and no identity class settled the question.
No source is stored against this line.
What is in the pack
One tablet once daily, with or without food, for 12 or 16 weeks depending on genotype, prior treatment and the baseline NS5A resistance test in genotype 1a. Grazoprevir is not sold separately.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold and what that means for what is in the pack.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take◇Read from sources, not yet reviewed
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
·Worth asking a clinician aboutWritten into the record from the studies named on this page
Boxed warning for hepatitis B virus reactivation, which has caused fulminant hepatitis, hepatic failure and death, requiring both HBsAg and anti-HBc before treatment. Contraindicated in Child-Pugh B or C hepatic impairment, in any history of hepatic decompensation, with OATP1B1/3 inhibitors, with strong CYP3A inducers and with efavirenz. Liver enzymes must be checked before therapy and at week 8, with a further check at week 12 on the 16-week regimen; about 1% of subjects developed ALT above five times the upper limit of normal, generally late in treatment and usually asymptomatic. In C-EDGE, serious adverse events were 2.8% on treatment against 2.9% on placebo, and in C-EDGE CO-INFECTION no patient discontinued for an adverse event.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear◇Read from sources, not yet reviewed
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Oral fixed-dose combination tablet with elbasvir
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form used in the studies cited on this page.
No source is stored against this line.
What is sold
Grazoprevir is not sold separately.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on which forms are sold and how they compare.
No source is stored against this line.
What is recorded as being sold
4 products list this as an active ingredient in the United States drug directory. 2 of them contain it and nothing else.
FDA National Drug Code directory · 50473-0098 · read 2026-08-29
They are sold as powder and tablet, film coated, taken oral.
FDA National Drug Code directory · 50473-0098 · read 2026-08-29
1 published label names it as an active ingredient. None of them describes this substance alone, so no label text on this page can be attributed to it rather than to a combination.
US prescribing information · 164dc02a-9180-426a-b8b5-04ab39d2bbd4 · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · 164dc02a-9180-426a-b8b5-04ab39d2bbd4 · read 2026-08-29
ZEPATIER is oral at 3 DOSAGE FORMS AND STRENGTHS ZEPATIER is available as a beige-colored, oval-shaped, film-coated tablet debossed with "770" on one side and plain on the other., recorded as fda label in effect 2026-03-13 in the United States.
US prescribing information · 164dc02a-9180-426a-b8b5-04ab39d2bbd4 · read 2026-08-30
Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.
What it would be like to take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
RNAWiki could not confidently classify this substance, so no self-experiment plan is offered.
Questions worth asking
Which of the trials of Grazoprevir Anhydrous studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
Claims that go past the evidence
Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.
✗Goes past the evidence
That a 7 pM biochemical IC50 describes potency in a patient; the same drug reads about a hundredfold weaker in a replicon
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the 96% co-infection and 99% kidney-disease results were established against concurrent controls — one study had no comparator, the other used its control arm for safety
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the ALT subgroup differences in women, Asian patients and older patients are established risk factors; the denominators are 4 of 164 and 3 of 177
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That curing hepatitis C in advanced kidney disease reduces death or graft failure, which C-SURFER cites as its rationale and did not measure
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Grazoprevir Anhydrous are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Every line above can be traced to the study named beside it. Follow the link and read it.
Q80K, which forced testing before simeprevir, has no effect here
In plain words
A common natural variant in genotype 1a hepatitis C had crippled the previous generation of protease inhibitors badly enough that patients had to be screened for it. Grazoprevir is unaffected by it, and that was the point of the molecule.
What was measured
Fold-change in grazoprevir activity by NS3 substitution: none at Q80K/R, 110- to 320-fold at genotype 4 D168A/V
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
In genotype 1a replicons, single NS3 substitutions V36L/M, Q80K/R and V107I had no impact on grazoprevir antiviral activity in cell culture, and in the clinical dataset the NS3 Q80K polymorphism did not affect treatment response in genotype 1a-infected subjects. The structural reason is architectural: grazoprevir is a P2-to-P4 macrocycle, whereas simeprevir and the first-generation inhibitors span P1 to P3 and make contact near position 80. The advance is real, measured, and specific — it does not extend to the positions that do matter, where single substitutions Y56H, R155K, A156G/T/V and D168A/E/G/N/S/V/Y cost 2- to 81-fold in genotype 1a, up to 375-fold in genotype 1b at A156, and 110- to 320-fold in genotype 4 at D168.
Source
ZEPATIER United States prescribing information, Microbiology 12.4, resistance in cell culture and in clinical studies (NDA 208261)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
C-EDGE: 95% cured, with serious adverse events no more common than on placebo
In plain words
A blinded, placebo-controlled trial of 421 previously untreated people found 95% of those treated were cured, including 97% of those with cirrhosis, and serious side effects at 2.8% against 2.9% on placebo.
What was measured
Sustained virologic response at 12 weeks and serious adverse events, against a concurrent blinded placebo arm
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
C-EDGE TREATMENT-NAIVE randomised 421 treatment-naive adults with genotype 1, 4 or 6 infection 3:1 to immediate or deferred fixed-dose grazoprevir 100 mg with elbasvir 50 mg for 12 weeks, at 60 centres. SVR12 in the immediate-treatment group was 95% (299/316; 95% CI 92 to 97), with 92% (144/157) in genotype 1a, 97% (68/70) with cirrhosis and 80% (8/10) in genotype 6. Serious adverse events occurred in 9 patients (2.8%) on active treatment and 3 (2.9%) on placebo, difference under 0.05 percentage points (95% CI -5.4 to 3.1), none considered drug related. The commonest events were headache (17%), fatigue (16%) and nausea (9%).
Written into the record, not signed off as a reviewed claim
C-EDGE CO-INFECTION: 96% of 218 patients with HIV, and every cirrhotic patient cured
In plain words
In 218 people living with HIV and hepatitis C, 210 were cured. All 35 who had cirrhosis were cured. Nobody stopped treatment because of a side effect.
What was measured
Sustained virologic response at 12 weeks in HIV/HCV co-infection
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
C-EDGE CO-INFECTION was a non-randomised, open-label, single-arm phase 3 study in 218 treatment-naive patients with genotype 1, 4 or 6 hepatitis C and HIV co-infection, either antiretroviral-naive or stable on therapy for at least 8 weeks, at 37 centres in nine countries. SVR12 was 96% (210/218; 95% CI 92.9 to 98.4). One failure was for a non-virological reason and seven non-cirrhotic patients relapsed, two of which were subsequently confirmed as reinfections rather than treatment failures. All 35 patients with cirrhosis achieved SVR12. Commonest events were fatigue (13%), headache (12%) and nausea (9%), with no discontinuations for adverse events. Two patients on antiretroviral therapy had transient HIV viraemia.
Written into the record, not signed off as a reviewed claim
Twelvefold higher exposure in severe liver impairment, hence a contraindication
In plain words
The drug is actively pumped into the liver and leaves in bile. When the liver fails, it accumulates: in people with the most severe liver impairment, blood levels were twelve times higher than normal. The label forbids its use there.
What was measured
Twelvefold increase in grazoprevir exposure in Child-Pugh C subjects; >90% faecal and <1% urinary excretion
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
ZEPATIER is contraindicated in moderate hepatic impairment (Child-Pugh B) for lack of clinical safety and efficacy experience, and in severe hepatic impairment (Child-Pugh C) because of a twelvefold increase in grazoprevir exposure measured in non-HCV-infected Child-Pugh C subjects. It is also contraindicated in any patient with a history of hepatic decompensation, and postmarketing cases of hepatic decompensation and failure have been reported in patients with advanced liver disease. The mechanism is the drug’s own design: grazoprevir distributes predominantly to the liver by active transport through OATP1B1/3, more than 90% of a radiolabelled dose is recovered in faeces and less than 1% in urine, so hepatic clearance is the only meaningful exit. The same property that makes it usable in kidney failure makes it unusable in liver failure.
Source
ZEPATIER United States prescribing information, Contraindications 4, Use in Specific Populations 8.9 and Clinical Pharmacology 12.3 (NDA 208261)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Late liver enzyme rises in about one in a hundred, and unevenly distributed
In plain words
About 1% of people had liver enzymes rise from normal to more than five times the upper limit, usually after week 8. The rate was double that in women, in Asian patients and in people over 65.
What was measured
ALT rise from normal to more than 5x upper limit of normal in 1% overall; 2% in women, Asian patients and those aged 65 or older
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
During clinical trials with or without ribavirin, 1% of subjects experienced elevations of ALT from normal levels to greater than five times the upper limit of normal, generally at or after treatment week 8. The elevations were typically asymptomatic and most resolved with ongoing or completed therapy. Higher rates occurred in three subpopulations: female sex 2% (10/608), Asian race 2% (4/164), and age 65 or older 2% (3/177). The label therefore requires hepatic laboratory testing before therapy, at treatment week 8, and again at week 12 for patients on the 16-week regimen, with discontinuation if ALT stays above ten times the upper limit or if elevation is accompanied by signs of liver inflammation or rising conjugated bilirubin. The subgroup denominators are small — 4 of 164 and 3 of 177 — so the twofold differences are unstable estimates rather than established risk factors.
Source
ZEPATIER United States prescribing information, Warnings and Precautions 5.2 (NDA 208261)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
A picomolar enzyme number and a nanomolar cell number, both on the same label
In plain words
Against the isolated viral enzyme, grazoprevir works at seven trillionths of a gram per litre. Inside a living cell it needs about fifty to a hundred times more. Both figures are printed in the label, and only one of them describes what happens in a patient.
What was measured
That a picomolar biochemical IC50 describes potency in a patient — the same drug reads roughly a hundredfold weaker in a cell, and the label reports both
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
In the biochemical assay grazoprevir inhibited recombinant NS3/4A protease from genotypes 1a, 1b and 4a with IC50 values of 7 pM, 4 pM and 62 pM. In full-length replicon assays the EC50 values for the same genotypes were 0.4 nM, 0.5 nM and 0.3 nM. The gap is not an error and it is not unusual — it is what membrane permeability, plasma-protein binding, active transport and intracellular sequestration cost between a purified enzyme and a living cell. It matters because the picomolar figure is the one most likely to be quoted, and because a comparison between two drugs is meaningless unless both numbers come from the same kind of assay. Elbasvir, quoted at 4 pM in this batch, is a replicon number; grazoprevir at 7 pM is an enzyme number.
Source
ZEPATIER United States prescribing information, Microbiology 12.4, mechanism of action and antiviral activity (NDA 208261)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Three categories of outright contraindicated co-medication
In plain words
Some medicines cannot be taken with this one at all: drugs that push its levels up through the liver uptake pump, drugs that strip it out, and efavirenz by name.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
The regimen is contraindicated with inhibitors of the organic anion transporting polypeptides OATP1B1/3 that are known or expected to significantly increase grazoprevir concentrations, with strong inducers of CYP3A, and with efavirenz. The transporter dependence explains the shape of the list: because grazoprevir is delivered into hepatocytes by OATP1B1/3 rather than by passive diffusion, blocking that transporter raises systemic exposure of a drug whose liver toxicity is already exposure-related and whose Child-Pugh C exposure is twelvefold elevated. Both elbasvir and grazoprevir are partially eliminated by CYP3A oxidation, which is the second half of the list.
Source
ZEPATIER United States prescribing information, Contraindications 4 and Clinical Pharmacology 12.3 (NDA 208261)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Neither co-infection nor kidney-disease efficacy was established against a control
In plain words
The HIV trial had no comparison group at all. The kidney trial had a placebo group but used it only to judge safety; the cure rate was compared against a number from older interferon studies.
What was measured
That the 96% and 99% figures in co-infection and kidney disease were established against concurrent controls — one trial had none, and the other used its control arm for safety only
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
C-EDGE CO-INFECTION describes itself as an uncontrolled, non-randomised, open-label, single-arm study. C-SURFER describes itself as a phase 3 randomised study of safety and observational study of efficacy: the primary efficacy outcome was a non-randomised comparison of SVR12 against a historical control of 45% derived from meta-analyses of interferon-based regimens in haemodialysis patients, while the randomised immediate-against-deferred comparison served the safety endpoint. Both designs were reasonable in 2015 and both produced strong numbers — 96% and 99%. Neither number is a randomised efficacy result, and the 45% comparator comes from a different drug class, a different era and a differently selected population.
Written into the record, not signed off as a reviewed claim
Every endpoint is a blood test twelve weeks after the last tablet
In plain words
C-EDGE, C-EDGE CO-INFECTION and C-SURFER all measured virus in blood. None counted deaths, cancers, transplants, graft failures or dialysis outcomes.
What was measured
That an undetectable blood test twelve weeks after treatment predicts fewer deaths, cancers or graft failures — plausible, and not what any of these trials measured
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The 2017 Cochrane review of 138 randomised direct-acting antiviral trials in 25,232 participants found no usable randomised evidence on hepatitis C-related morbidity or on hepatocellular carcinoma, and mortality data from only 11 trials. C-SURFER states its own rationale as the increased risk of death and renal graft failure in this population, and then measures viral RNA at twelve weeks. C-EDGE CO-INFECTION notes that two of its seven relapses were subsequently confirmed as reinfections rather than treatment failures — a reminder that even the surrogate is measuring something slightly different from what it is read as.
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What is not here
7 questions this page could not answer
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What was measured, goal by goal — found nothing in the sources checked.
How close this is to real life — found nothing in the sources checked.
Felt, measured, or meaningful — found nothing in the sources checked.
How long anything takes — found nothing in the sources checked.
What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
What changed on this page — found nothing in the sources checked.
The record as stored
The full record, for auditing
Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.
The older medicine-wide conclusion held in this record
Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.
An NS3/4A protease inhibitor that blocks the recombinant enzyme at 7, 4 and 62 picomolar across genotypes 1a, 1b and 4a and is untouched by the Q80K variant that defeated simeprevir, curing 95% of 316 previously untreated patients, 96% of 218 with HIV co-infection and 99% of 116 with stage 4 or 5 kidney disease — and contraindicated in Child-Pugh C liver disease because grazoprevir exposure rises twelvefold there.
Recorded evidence blocks (6)
Q1
49 registered trials of Grazoprevir Anhydrous — at which phases?
Registered studies posting no result
18 of 49
49 registered studies of Grazoprevir Anhydrous: 19 phase2, 16 phase4, 8 phase1, 7 na or unstated, 5 phase3. CLINICALTRIALS_SNAPSHOT · 2026-09-01
55 with a PubMed record
Show the evidence
phase2
19
phase4
16
phase1
8
na or unstated
7
phase3
5
completed
34
3 more recorded rows
terminated
6
withdrawn
6
unknown
3
recorded 2026-09-01 · last checked 2026-09-04
Q2
11 of Grazoprevir Anhydrous's trials stopped: accrual/recruitment, funding/business, other?
accrual/recruitment (5), funding/business (2) and other (4): Grazoprevir Anhydrous's stop wording, clustered. CLINICALTRIALS_SNAPSHOT · 2026-09-01
"Preliminary results of MK-5172 PN003 (NCT01353911) suggested a possible dose relationship to elevated transaminase levels in treatment with grazoprevir."; 11 of 49 registered studies
Show the evidence
Trial
NCT01440595
terminated; "Preliminary results of MK-5172 PN003 (NCT01353911) suggested a possible dose relationship to elevated transaminase levels in treatment with grazoprevir."
NCT02895958
terminated; "Insufficient study participants enrolled"
NCT02940691
terminated; "Poor recruitment due to new treatments becoming available."
NCT03026023
withdrawn; "moved forward with another protocol utilizing pan genotypic treatment once it became commercially available and FDA approved"
NCT03093740
withdrawn; "Withdrew IRB application, never approved and no subjects enrolled"
NCT03105349
withdrawn; "No availability of investigational medication."
5 further recorded trials
NCT03143998
withdrawn; "Business reasons"
NCT03221582
terminated; "Site unable to recruit the agreed upon number of participants"
NCT03723824
terminated; "COV-19 pandemic"
NCT03791814
withdrawn; "The study was stopped due to difficulty in identifying potential patients."
NCT03797066
terminated; "Changing parameters in HCV management, resulted in poor recruitment; additionally onset of SARS CoV2 resulted in the cessation of all mobile clinical services."
recorded 2026-09-01 · last checked 2026-09-04
Q3
Human studies of Grazoprevir Anhydrous used 800 mg Grazoprevir — over how long?
Human studies of Grazoprevir Anhydrous used "800 mg Grazoprevir". ClinicalTrials.gov · 2026-09-01
11 recorded entries; human; also "100 mg Grazoprevir", "Grazoprevir 100 mg/d 8 weeks", "MK-5172 100 mg"
Which 5 trials of Grazoprevir Anhydrous posted no result?
Posted no result
5 of 5 completed trials
Registrations
NCT02333292, NCT03186365, NCT03706222, NCT04047680 and NCT04048850
Completion dates
oldest 2017-06-30; newest 2022-09-09
Show the evidence
Trial
NCT02333292
2017-06-30
NCT03186365
2018-09-19
NCT03706222
2019-02-25
NCT04047680
2019-06
NCT04048850
2022-09-09
Q5
At the median, Grazoprevir Anhydrous's trials enrolled 50 people — anything larger?
Median enrolment
50
Largest enrolment
2438
Registered trials counted
49
Q6
What do 1595 spontaneous reports say about Grazoprevir Anhydrous — and not say?
These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.
Grazoprevir Anhydrous appears in spontaneous reports to regulators. Across the 8 most-reported reaction terms, 1595 reaction mentions were counted: fatigue 577; headache 432; nausea 269; diarrhoea 138. FAERS via Open Targets · CHEMBL2063090 · 2026-06-24
Show the evidence
fatigue
577
headache
432
nausea
269
diarrhoea
138
insomnia
133
hepatitis c
43
2 more recorded rows
drug hypersensitivity
2
hypotension
1
recorded 2026-06-24 · last checked 2026-09-04
Where it is registeredIdentifiers, relations and other names
ChEMBL 37 — CC BY-SA 3.0 Unported · ClinicalTrials.gov — US Government work · Open Targets 26.06 — CC0 · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md
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✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 5 source rows
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✓ canonical metadata passed: slug and display name present
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