Biochemical and viral response to consensus interferon (CIFN) therapy in chronic hepatitis C patients: effect of baseline viral concentration. Consensus Interferon Study Group.
OBJECTIVE
The effect of baseline viral concentration on response was assessed as part of a multicenter phase 3 trial evaluating the safety and efficacy of CIFN therapy for chronic HCV infection.


METHODS
Patients (n = 472) received either CIFN 9 microg or IFN alpha-2b 3 MU subcutaneously t.i.w. for 24 wk, followed by 24 wk of observation.


RESULTS
Efficacy was assessed by the percentage of patients who achieved normal ALT values or undetectable HCV RNA values (using RT-PCR with a sensitivity of 100 copies/ml). There was a clear relationship between baseline viral concentration and either ALT or HCV RNA response; patients with lower titer HCV RNA had better response rates. End-of-treatment HCV RNA responses were better for patients with low viral concentrations treated with CIFN (51%) than for patients treated with IFN a-2b (31%) (p = 0.03). ALT responses in patients with low viral concentrations were 60% for CIFN-treated patients and 27% for IFN alpha-2b-treated patients (p < 0.01) at the end of treatment. Patients with high titer HCV RNA were more likely to have a sustained HCV RNA response after treatment with CIFN 9 microg, compared with those treated with IFN alpha-2b (7% vs 0%, p = 0.03).


CONCLUSIONS
Both genotype and baseline viral concentration were independent factors that affected response to interferon.
Jensen
D M
DM
Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA.
Krawitt
E L
EL
Keeffe
E B
EB
Hollinger
F B
FB
James
S P
SP
Mullen
K
K
Everson
G T
GT
Hoefs
J C
JC
Fromm
H
H
Black
M
M
Foust
R T
RT
Pimstone
N R
NR
Heathcote
E J
EJ
Albert
D
D
D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D007279:Injections, Subcutaneous; D007370:Interferon Type I / Q000008:administration & dosage*; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood; D011994:Recombinant Proteins; D016896:Treatment Outcome; D019562:Viral Load
D000998:Antiviral Agents; D007370:Interferon Type I; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012367:RNA, Viral; D011994:Recombinant Proteins; C050739:interferon alfacon-1; D000410:Alanine Transaminase