HAART Followed by Treatment Interruption Provides No Benefit for Patients with Primary HIV Infection

Most studies of structured treatment interruption, including the SMART and Staccato trials, have focused on patients with long-established HIV infection.

A study presented at the recent XVI International AIDS Conference in Toronto, however, looked at antiretroviral therapy followed by treatment interruptions in individuals with primary or acute HIV infection.

The French PRIMSTOP (ANRS 100) trial enrolled 29 patients with early symptomatic primary HIV infection. Participants received HAART for 34 weeks, then began a structured treatment interruption phase that consisted of three treatment breaks lasting 2, 4, and 8 weeks, interspersed with 12 weeks on therapy.

Results from the study were previously reported in the November 1, 2005 Journal of Acquired Immune Deficiency Syndromes. Data presented at the conference were from a longer-term follow-up analysis performed in December 2005, after a median duration of 36 months (range 20-43) after HAART discontinuation.

Results

Of the 26 patients who completed the trial, none restarted HAART within 6 months after treatment discontinuation.

As previously reported, only 1 patient (3.8%) achieved an HIV RNA level less than 50 copies/mL, though 6 subjects (23.1%) had viral loads below 1000 copies/mL.

In the longer-term follow-up analysis, 6 patients (27%) restarted HAART after a median of 12 months (range 7-25).

Patients restarted HAART with a median CD4 cell count of 245 cells/mm3 (range 197-266) and a median viral load of 4.75 log copies/mL (range 3.86-5.44).

Among those who restarted was the single patient whose viral load was below 50 copies/mL throughout the 6 months immediately following HAART discontinuation.

Among the 16 patients who did not restart HAART during the 30 months after treatment discontinuation:

- the median CD4 count was 456 cells/mm3 (range 333-639);
- the median CD4 cell decrease was 240 cells/mm3;
- the median viral load increase was 3.1 log copies/mL;
- 11 patients (68%) had viral loads greater than 4 log copies/mL.

One patient experienced clinical progression (oral candidiasis) and one developed non-Hodgkins lymphoma.

Conclusion

In conclusion, the researchers wrote, "These data show that virtually no primary HIV infection patient can maintain suppression of viremia after a sequence of HAART/structured treatment interruptions followed by HAART discontinuation." In addition, they added, "a significant proportion of them need to restart HAART, due to CD4 decrease below 300 cells/mm3."

The results of this study provide evidence against the hypothesis that treatment interruption might stimulate the immune system to better respond to and control HIV.

09/01/06

References

B Hoen, C Deveau, I Fournier, and others. Absence of sustained benefit of HAART followed by structured treatment interruptions in primary HIV-1 infection: prolonged follow-up of patients enrolled in the PRIMSTOP (ANRS 100) trial. XVI International AIDS Conference. Toronto, August 13-18, 2006. Abstract MOPE0059/7495.

B Hoen, I Fournie, C Lacabaratz, and others. Structured treatment interruptions in primary HIV-1 infection: the ANRS 100 PRIMSTOP trial. Journal of Acquired Immune Deficiency Syndromes 40(3): 307-316. November 1, 2005.