In both groups, TB-IRIS occurred in about 6%, cryptococcal-IRIS in about 2%, and IRIS of unknown etiology in about 2%. Also in both groups, IRIS risk was highest among older subjects as well as those who went into treatment with particularly low CD4 counts or tuberculosis (TB).
“Basically, the increase in IRIS was not there. We believe these results can be extrapolated across the class of integrase inhibitors. This provides great reassurance,” especially given the prospect of first-line integrase inhibitors in developing countries, where patients tend to present with more advanced disease, said lead investigator Diana Gibb, MD, an epidemiology professor and researcher at the University College London at the Conference on Retroviruses and Opportunistic Infections.
The wrinkle in the findings was that “we didn’t see any benefit to adding raltegravir to the first 12 weeks of treatment. Everyone thought that by [driving] down the viral load faster, you might get less disease progression, and so fewer deaths. We didn’t see any difference at all. The mortality was identical at 24 weeks [around 10.5% in both arms] and at 48 weeks [around 12.5%]. The same if you looked at” severe AIDS complications, she said.
Fast, steep declines in VL “might not necessarily translate” to clinical benefit, Dr. Gibb said.
What did make a difference was IRIS prophylaxis.