Safety and efficacy of lamivudine-zidovudine combination therapy in zidovudine-experienced patients. A randomized controlled comparison with zidovudine monotherapy. Lamivudine European HIV Working Group.
OBJECTIVE
To compare the safety and efficacy of 2 doses of lamivudine given in combination with zidovudine with continued zidovudine monotherapy.


METHODS
Double-blind, randomized, multicenter, comparative trial of 223 patients treated for 24 weeks.


METHODS
Patients from 32 hospitals in Europe were enrolled throughout a 1-year period.


METHODS
Adult human immunodeficiency virus type 1 (HIV-1)-positive, zidovudine-experienced ( > or = 24 weeks prior zidovudine) patients with CD4+ cell counts between 0.10 and 0.40 x 10(9)/L (100-400 cells/microL).


METHODS
Patients received either 200 mg of zidovudine every 8 hours, 150 mg of lamivudine every 12 hours plus zidovudine, or 300 mg of lamivudine every 12 hours plus zidovudine for 24 weeks. All patients were then allowed to receive zidovudine and open-label lamivudine combination therapy. Twelve patients withdrew because of adverse events during the 24-week treatment period.


METHODS
Efficacy was measured by evaluating immunological and viral load changes, and safety was assessed by evaluating clinical manifestations and laboratory indexes of toxic effects.


RESULTS
Patients receiving low- or high-dose combination therapy had greater treatment effects compared with patients receiving continued zidovudine monotherapy during the first 24 weeks as documented by changes in CD4+ cell counts (+0.04 vs +0.03 vs -0.02 x 10(9)/L, respectively; P < .001); log10 HIV-1 RNA as measured by the Roche assay (-0.96 vs -0.77 vs +0.07 copies/mL, respectively; P < .001) or log10 HIV-1 RNA measured by the quantitative nucleic acid sequence-based amplification assay (-0.59 vs -1.06 vs -0.02 copies/mL, respectively; P < .011); and immune-complex dissociated (ICD) p24 antigen (-74% vs -68% vs +27%, respectively; P < .001). There were no statistically significant differences in viral measurements, in CD4+ cell counts, or in safety profile between the groups receiving 2 doses of lamivudine in combination with zidovudine. The effects on CD4+ cell counts and ICD p24 antigen were sustained throughout 48 weeks for patients continuing combination therapy. Patients switching to combination therapy at week 24 showed improvement.


CONCLUSIONS
In zidovudine-experienced HIV-1-infected patients, combination treatment with lamivudine and zidovudine is well tolerated and provides greater and more sustained increases in CD4+ cell counts and decreases in viral load than continued zidovudine monotherapy.
Staszewski
S
S
Klinikum der Johann Wolfgang Goethe Universität, Frankturt, Germany.
Loveday
C
C
Picazo
J J
JJ
Dellarnonica
P
P
Skinhøj
P
P
Johnson
M A
MA
Danner
S A
SA
Harrigan
P R
PR
Hill
A M
AM
Verity
L
L
McDade
H
H
D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004352:Drug Resistance, Microbial / Q000235:genetics; D004359:Drug Therapy, Combination; D005838:Genotype; D016655:HIV Core Protein p24 / Q000032:analysis; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics; D006801:Humans; D019259:Lamivudine; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000097:blood; D018894:Reverse Transcriptase Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D016047:Zalcitabine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D015215:Zidovudine / Q000008:administration & dosage / Q000627:therapeutic use*
D000998:Antiviral Agents; D016655:HIV Core Protein p24; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; D015215:Zidovudine; D016047:Zalcitabine