Project no.: HIV-NAT 116 (Rifabutin with Lopinavir/Ritonavir)
This is a pilot, randomized, open-label, 2-arm per group, parallel, phase II study that will describe the pharmacokinetics of rifabutin 150 mg once daily versus rifabutin 300 mg thrice weekly in combination with LPV/r 400/100 mg based HAART in HIV/TB infected patients.
Results: A total of 21 patients were enrolled in the study. 10 patients were randomized to RFB 150mg QD and 11 patients received RFB 300mg TIW. AUC of RFB 150mg QD combined with LPV/r is moderately higher than RFB alone ( 41.9%). and AUC over 48 hours in patients with RFB 300 mg TIW combined with LPV/r is 23% higher than RFB alone. Geometric mean Cmax (CV) of RFB 150mg QD +LPV/r and 300mg QD alone were similar 0.65 mg/L versus 0.66mg/L, whereas the Cmax after RFB 300mg TIW + LPV/r was 24% higher.Exposure to desmetRFB was 1060% and 837% higher for 150mgRFB QD+LPV/r and 300mgRFB TIW+LPV/r. Overall RFB and desmetRFB exposure were 14% and 22% lower for the 300mgRFB TIW group compared to the 150mgRFB QD group. Pharmacokinetic parameters of LPV/r are in therapeutic level and were similar in both arms. Every patient in this study was cured from TB but uveitis which is associated to rifabutin developed in two patients who received RFB 300mg TIW.
(Source: Fujitnirun C, et al. Pharmacokinetics of rifabutin 150 mg qd vs 300 mg tiw with LPV/R in HIV/TB patients. Abstract 781. Presented at CROI 2018)
