 HAART
Containing Tenofovir (Viread) plus Emtricitabine (Emtriva) Is Effective for HIV-HBV
Coinfected Patients, but Treatment Should Not Be Interrupted
By
Liz Highleyman Several
recent studies have added to the evidence that structured interruption of antiretroviral
therapy can lead to detrimental outcomes for people
with HIV.
The disadvantages of treatment interruption may be even more
pronounced among HIV positive individuals
with hepatitis B virus (HBV) coinfection, since some drugs used to treat HIV
are also active against HBV, including 3TC (lamivudine;
Epivir), emtricitabine (Emtriva),
and tenofovir (Viread). Emtricitabine
and tenofovir are the 2 drugs in the Truvada fixed-dose combination pill and -
along with efavirenz (Sustiva)
- are components of the Atripla combination
pill.
Discontinuation of these drugs may not only lead to loss of
HBV suppression, but can also trigger hepatitis "flares" characterized
by elevated transaminases (the liver enzymes ALT and AST).
In the January
2, 2008 issue of AIDS, researchers reported data from an analysis of 16
HIV-HBV coinfected (but HCV negative) Thai patients in the STACCATO trial (out
of a total 362 Thai participants).
Patients taking HAART regimens containing
emtricitabine/tenofovir were randomly assigned to receive continuous therapy or
to undergo CD4 cell count-guided interruptions. Those in the treatment interruption
arm stopped antiretroviral therapy when their CD4 count was greater than 350 cells/mm3,
and restarted when the count fell below this level.
Liver enzyme levels
and HBV viral load were measured at weeks 4, 8, 12, and then every 12 weeks through
the end of the trial. A complete hepatitis B serology was performed when emtricitabine/tenofovir
was initiated and again at week 48. The median follow-up period was 69 weeks (range
48-96).
Individuals
undergoing treatment interruption who experienced ALT/AST levels 5 or more times
the upper limit or normal (ULN) or bilirubin more than 2.5 times ULN immediately
restarted emtricitabine/tenofovir-containing HAART.
Results •
HBV replication
was suppressed below the level of detection in 15 of 16 coinfected patients.
•
Overall,
patients in the treatment interruption arm had worse control of HBV and higher
transaminase levels.
•
After
treatment interruption, HBV DNA increased by a median 2.52 logs (range 0.49-4.70).
•
Transaminase
levels and HBV viral load increased during treatment interruption in 5 of 6 patients
(mostly asymptomatic).
•
1
individual experienced a severe hepatitis flare.
•
All
respond completely when emtricitabine/tenofovir-containing HAART was restarted.
•
1
patient in the continuous therapy arm became HB "e" antigen (HBeAg)
negative and developed HBe antibodies.
•
1
person on continuous therapy lost hepatitis B surface antigen (HBsAg) but did
not develop HBs antibodies.
•
Conversion
to HBe antibody positivity occurred only in the continuous treatment arm.
Conclusion
In
conclusion, the authors wrote, "Tenofovir/emtricitabine-containing antiretroviral
therapy is highly effective in controlling chronic HIV-HBV coinfection but treatment
should not be interrupted."
HIV-NAT, Thai Red Cross AIDS Research
Center, Bangkok, Thailand; Outpatient Clinic of Internal Medicine and Division
of Infectious Diseases, University Hospital, Basel, Switzerland; National Centre
in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney,
Australia; Khon Kaen University, Khon Kaen, Thailand; Bamrasnaradura Institute,
Nonthaburi, Thailand; Sanpatong Hospital, Chiang Mai, Thailand; Division des Maladies
Infectieuses, Geneva University Hospital, Geneva, Switzerland.
01/11/08
Reference
R
Nuesch, J Ananworanich, P Srasuebkul, and others. Interruptions of tenofovir/emtricitabine-based
antiretroviral therapy in patients with HIV/hepatitis B virus co-infection. AIDS
22(1): 152-154. January 2, 2008. |
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