HIV-1 resistance to dolutegravir: update and new insights

Integrase strand transfer inhibitors (INSTIs) are the latest class of potent anti-HIV drugs. Currently, three INSTIs have been approved by the US Food and Drug Administration: raltegravir (RAL), elvitegravir (EVG) and dolutegravir (DTG). Resistance mutations to RAL and EVG emerge rapidly, and significant cross-resistance between these compounds has been documented. In addition, limited cross-resistance has been observed among DTG, a newer INSTI, and RAL and EVG even though clinical resistance to DTG, or mutations associated with DTG resistance in treatment-naïve patients, has not yet been observed. This review summarises progress in studies on understanding resistance to DTG, mechanisms of possible resistance to DTG, and reasons for the absence of DTG-associated resistance mutations when the drug has been used in first-line therapy.