Does enfuvirtide increase the risk of bacterial pneumonia in patients receiving combination antiretroviral therapy?

Background: Pooled analysis of the TORO comparative clinical trial data sets showed a significantly higher incidence rate (IR) of bacterial pneumonia (BP) among patients treated with enfuvirtide-containing combination antiretroviral therapy (ENF-cART) than in those treated with other cART regimens.
Objectives: To examine the possible impact of ENF-cART on the risk of BP.
Methods: From the French Hospital Database on HIV, we selected two groups of patients among cART-treated patients who were prescribed a new cART regimen during the period 2001-2006, when their CD4 counts were <350 cells/mm(3). The ENF-cART and cART groups consisted of 1220 and 9374 patients, respectively. Poisson regression models were used to quantify the relationship between ENF-cART therapy and the risk of BP.
Results: At baseline the median CD4 counts were 100 and 211 cells/mm(3) and the median plasma viral load (pVL) values were 60 276 and 2702 copies/mL in the ENF-cART and cART groups, respectively. The respective BP IRs were 0.65 [95% confidence interval (CI) 0.25-1.06] and 0.31 (95% CI 0.25-0.38) cases per 100 person-years. After adjustment for age, the HIV transmission group, the time period, co-trimoxazole prophylaxis, and stratified CD4 cell counts and pVL values, we found that the BP risk ratio was not increased by enfuvirtide treatment (relative rate 1.39; 95% CI 0.46-4.13). In contrast, lower CD4 cell counts and higher pVL values were significantly associated with a higher risk of BP.
Conclusions: ENF-cART is not associated with a significantly higher risk of BP than other cART regimens, although the value of the adjusted risk and the upper limit of the CI do not allow us to exclude a small increased risk.