Accumulation of multiple mutations in vivo confers cross-resistance to new and existing integrase inhibitors.

Bictegravir (BIC) and cabotegravir (CAB) are the latest available HIV integrase inhibitors in clinical trials. The combination of major integrase inhibitor substitutions G140S/Q148H has been shown to confer high-level resistance to the approved integrase inhibitors raltegravir (RAL) and elvitegravir (EVG) but not necessarily dolutegravir (DTG). We assayed recombinant viruses made from patient-derived RNA extracts for resistance phenotype for a panel of viruses containing G140S/Q148H with additional accessory substitutions. The accumulation of multiple integrase substitutions confers high-level resistance to all 5 integrase inhibitors. There is extensive cross-resistance between DTG, BIC, and CAB (r = 0.96-0.97).