PI and NNRTI based regimens equally effective in treating KS, says study

A published study has shown for the first time that NNRTIs and protease inhibitor (PI)-based HAART regimens are equally effective in the treatment of the AIDS defining cancer Kaposi’s sarcoma (KS). In addition, the study, published in theJournal of Acquired Immune Deficiency Syndromes, demonstrated that PI and NNRTI regimens were equally likely to suppress to undetectable levels the reproduction of the virus thought to cause KS, and that people who achieve an undetectable HIV viral load are much more likely to see an improvement in their KS.

Investigators recruited 29 men to the study, 21 of whom had been diagnosed with KS. All the people enrolled in the study had either never received HAART before or had had very limited exposure to anti-HIV therapy.

On enrollment to the study, and then at four to twelve week intervals, patients had their HIV viral load and CD4 count measured. In addition, blood tests were performed to check viral load for KS associated herpes virus (KSHV, also called HHV-8) and for antibodies to KSHV. The average period of follow-up was 40 weeks (range four to 75 weeks).

It was established at baseline that neither the presence of antibodies to KSHV, nor a detectable KS viral load were related to CD4 count or HIV viral load. Nor were the amount of KSHV antibodies or higher KSHV viral loads related to baseline HIV viral loads.

A PI-based HAART regimen was provided to eight study members, an NNRTI regimen to eighteen, and a four drug regimen including both a PI and NNRTI to one person. Of the 21 people with KS, ten experienced an improvement in their KS (a complete response was noted in six and a partial response in four) on treatment with HAART alone. One person’s KS remained stable, and there was KS disease progression in three people. There was no difference in response between those receiving PI based regimens and NNRTI based treatments. Previous studies had suggested that people with KS should be treated with PIs.

Of the twenty people with detectable KSHV at baseline, twelve (60%) became undetectable with HAART. The four people at enrollment who had detectable KSHV viral load but no clinical evidence of KS achieved an undetectable KSHV viral load. Of the ten people whose KS improved with HAART, all but one was noted to have an undetectable KSHV viral load.

Furthermore, everybody whose KS improved on HAART had either an undetectable or very low (below 400 copies/mL) HIV viral load. However, only 45% of those who needed specific anti-KS therapy or who experienced KS disease progression had an undetectable HIV viral load. However, changes in CD4 count after treatment with HAART were not associated with improvement or worsening of KS.

The investigators conclude that both PI and NNRTI based regimens are equally effective at achieving an improvement in KS, and in “KSHV load clearance”, adding “our data suggest that a fall in HIV load plays an important role in the effect of KSHV load clearance and remission of AIDS and KS”.

For more information about KS click here.