Raltegravir approved in the US

On 12 October 2007, the Food and Drug Administration (FDA) granted accelerated approval for raltegravir (trade name Isentress), the first integrase inhibitors. Approval is based on efficacy and safety data from two double-blind, placebo-controlled studies (BENCHMRK 1 and 2) in 699 treatment-experienced HIV-1 infected adult patients (with documented resistance to at least 1 drug in each of NRTIs, NNRTI and PI classes), randomised 2:1 to receive either active drug or placebo, plus optimised background treatment.

The mean changes in plasma HIV-1 RNA from baseline were -1.85 log10 copies/mL in the raltegravir 400 mg twice daily arm and -0.84 log10 copies/mL for the control arm. The mean increase from baseline in CD4 cell counts were 89 cells and 35 cells/mm3, respectively.

The most common adverse events reported with raltegravir were diarrhoea, nausea, and headache. Blood tests showed abnormal elevated levels of a muscle enzyme in some patients receiving raltegravir. Caution is advised when using raltegravir in patients at increased risk for certain types of muscle problems, such as patients taking other medications that can cause muscle problems.

Comment

Raltegravir has already been filed in Europe, and a decision is expected by the new year.