Introduction: Rilpivirine (RPV) and Etravirine (ETR) are second-generation non-nucleoside reverse transcriptase inhibitors (NNRTIs) that are not used for HIV-1 treatment in Kenya. In this cross-sectional study, we analyzed the reverse transcriptase region of HIV-1 from 140 HIV-1 infected individuals from Busia County Referral Hospital, Busia County, Kenya, who were on treatment with confirmed virologic failure. Methods: All the patients were on first-generation NRTI’s and NNRTI’s for more than 12 months at the time of the study. Briefly, RNA was extracted from plasma samples and sequenced to analyze for the presence of HIV-1 drug resistance mutations. Results: The study findings showed that approximately 46% of the population had genotypic drug resistance against both Etravirine and Rilpivirine which was classified as ranging from potentially low level resistance to high level resistance despite being exposed to first-generation NNRTIs only. Conclusions: There was demonstrated cross-resistance between primary and secondary drug first line medications. The development of cross resistance for RPV and ETR in patients on EFV and NVP poses a challenge in the use of these drugs as second generation NNRTI drugs. Introduction: Rilpivirine (RPV) and Etravirine (ETR) are second-generation non-nucleoside reverse transcriptase inhibitors (NNRTIs) that are not used for HIV-1 treatment in Kenya. In this cross-sectional study, we analyzed the reverse transcriptase region of HIV-1 from 140 HIV-1 infected individuals from Busia County Referral Hospital, Busia County, Kenya, who were on treatment with confirmed virologic failure. Methods: All the patients were on first-generation NRTI’s and NNRTI’s for more than 12 months at the time of the study. Briefly, RNA was extracted from plasma samples and sequenced to analyze for the presence of HIV-1 drug resistance mutations. Results: The study findings showed that approximately 46% of the population had genotypic drug resistance against both Etravirine and Rilpivirine which was classified as ranging from potentially low level resistance to high level resistance despite being exposed to first-generation NNRTIs only. Conclusions: There was demonstrated cross-resistance between primary and secondary drug first line medications. The development of cross resistance for RPV and ETR in patients on EFV and NVP poses a challenge in the use of these drugs as second generation NNRTI drugs.

Keywords: NNRTIs, NRTIs, Kenya, cross-resistance, ETR, RPV, HIV-1.