Tenofovir alafenamide and rifabutin coadministration does not lead to loss of HIV-1 suppression: a retrospective observational study.

OBJECTIVES Tenofovir alafenamide (TAF) is a preferred nucleotide reverse transcriptase inhibitor used in the treatment of HIV. Coadministration of TAF with rifabutin (RFB) is not recommended due to concerns that RFB decreases TAF gastrointestinal absorption. The objective of this study was to determine the efficacy of ART regimens that included the coadministration of TAF and RFB. METHODS We retrospectively identified persons with HIV (PWH) who received TAF-RFB coadministration for ≥1 month. The primary outcome was the maintenance of HIV viral load <200 copies/ml (cpm) for those already on HIV therapy at RFB initiation or suppression of viral load to <200 cpm for those with unsuppressed HIV viral load prior to TAF-RFB coadministration. RESULTS 22 PWH met the inclusion criteria. Four out of five patients (80%) maintained viral load <200 cpm and 15/17 (88%) achieved viral load <200 cpm during TAF-RFB coadministration. After exclusion of patients that self-discontinued therapy or were lost to follow up, 19/19 (100%) met the combined primary endpoint of HIV viral load <200 cpm. CONCLUSIONS Our study suggests that TAF-RFB coadministration may be effective despite concerns that RFB could reduce TAF absorption.