Efficacy of boceprevir, an NS3 protease inhibitor, in combination with peginterferon alfa-2b and ribavirin in treatment-naive patients with genotype 1 hepatitis C infection (SPRINT-1): an open-label, randomised, multicentre phase 2 trial.
BACKGROUND
Peginterferon plus ribavirin achieves sustained virological response (SVR) in fewer than half of patients with genotype 1 chronic hepatitis C virus infection treated for 48 weeks. We tested the efficacy of boceprevir, an NS3 hepatitis C virus oral protease inhibitor, when added to peginterferon alfa-2b and ribavirin.


METHODS
In part 1 of this trial, undertaken in 67 sites in the USA, Canada, and Europe, 520 treatment-naive patients with genotype 1 hepatitis C virus infection were randomly assigned to receive peginterferon alfa-2b 1.5 mug/kg plus ribavirin 800-1400 mg daily for 48 weeks (PR48; n=104); peginterferon alfa-2b and ribavirin daily for 4 weeks, followed by peginterferon alfa-2b, ribavirin, and boceprevir 800 mg three times a day for 24 weeks (PR4/PRB24; n=103) or 44 weeks (PR4/PRB44; n=103); or peginterferon alfa-2b, ribavirin, and boceprevir three times a day for 28 weeks (PRB28; n=107) or 48 weeks (PRB48; n=103). In part 2, 75 patients were randomly assigned to receive either PRB48 (n=16) or low-dose ribavirin (400-1000 mg) plus peginterferon alfa-2b and boceprevir three times a day for 48 weeks (low-dose PRB48; n=59). Randomisation was by computer-generated code, and study personnel and patients were not masked to group assignment. The primary endpoint was SVR 24 weeks after treatment. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00423670.


RESULTS
Patients in all four boceprevir groups had higher rates of SVR than did the control group (58/107 [54%, 95% CI 44-64], p=0.013 for PRB28; 58/103 [56%, 44-66], p=0.005 for PR4/PRB24; 69/103 [67%, 57-76], p<0.0001 for PRB48; and 77/103 [75%, 65-83], p<0.0001 for PR4/PRB44; vs 39/104 [38%, 28-48] for PR48 control). Low-dose ribavirin was associated with a high rate of viral breakthrough (16/59 [27%]), and a rate of relapse (six of 27 [22%]) similar to control (12/51 [24%]). Boceprevir-based groups had higher rates of anaemia (227/416 [55%] vs 35/104 [34%]) and dysgeusia (111/416 [27%] vs nine of 104 [9%]) than did the control group.


CONCLUSIONS
In patients with untreated genotype 1 chronic hepatitis C infection, the addition of the direct-acting antiviral agent boceprevir to standard treatment with peginterferon and ribavirin after a 4-week lead-in seems to have the potential to double the sustained response rate compared with that recorded with standard treatment alone.


BACKGROUND
Merck.
Kwo
Paul Y
PY
Department of Medicine, Division of Gastroenterology/Hepatology, Indiana University School of Medicine, Indianapolis, IN 46202-5121, USA. pkwo@iupui.edu
Lawitz
Eric J
EJ
McCone
Jonathan
J
Schiff
Eugene R
ER
Vierling
John M
JM
Pound
David
D
Davis
Mitchell N
MN
Galati
Joseph S
JS
Gordon
Stuart C
SC
Ravendhran
Natarajan
N
Rossaro
Lorenzo
L
Anderson
Frank H
FH
Jacobson
Ira M
IM
Rubin
Raymond
R
Koury
Kenneth
K
Pedicone
Lisa D
LD
Brass
Clifford A
CA
Chaudhri
Eirum
E
Albrecht
Janice K
JK
D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D019698:Hepatitis C, Chronic / Q000188:drug therapy*; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011392:Proline / Q000031:analogs & derivatives* / Q000627:therapeutic use; D011480:Protease Inhibitors / Q000627:therapeutic use; D011994:Recombinant Proteins; D012254:Ribavirin / Q000627:therapeutic use*; D019562:Viral Load; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011092:Polyethylene Glycols; D011392:Proline; D011480:Protease Inhibitors; D011994:Recombinant Proteins; D012254:Ribavirin; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C512204:N-(3-amino-1-(cyclobutylmethyl)-2,3-dioxopropyl)-3-(2-((((1,1-dimethylethyl)amino)carbonyl)amino)-3,3-dimethyl-1-oxobutyl)-6,6-dimethyl-3-azabicyclo(3.1.0)hexan-2-carboxamide; C417083:peginterferon alfa-2b