Emergent resistance to dolutegravir among INSTI-naïve patients on first-line or second-line antiretroviral therapy: a review of published cases

None of the licensing studies of dolutegravir (DTG) reported any treatment-emergent resistance among DTG-treated individuals, though virological failure in treatment-naïve and treatment-experienced, integrase strand transfer inhibitor (INSTI)-naïve individuals has been reported in clinical practice. While the spectrum of dolutegravir-selected mutations and their effects on clinical outcome have been described, the clinical characteristics of these rare but important virological failure cases are often overlooked. In this perspective piece, we focus on key clinical aspects of emergent resistance to DTG among treatment-naïve and treatment-experienced INSTI-naïve patients, with an aim to inform clinical decision-making. Poor adherence and HIV disease factors contribute to emergent drug resistance, even in regimens with high resistance barriers. Patients with severe immunosuppression or poor adherence are under-represented in licensing studies, and these patients may be at higher risk of treatment failure with DTG resistance, which requires close clinical and laboratory follow-up.