VIKING was a 24-week, Phase IIb pilot study designed to examine safety and efficacy of DTG in treatment-experienced subjects with genotypic evidence of RAL resistance.43 It was a multicenter study including 25 study sites. Initially patients were treated with DTG 50 mg daily; however, the protocol was amended to include a second cohort (DTG 50 mg twice daily) due to low viral load response among some patients in cohort one. Patients in cohort two were also required to have one fully active antiretroviral agent in the optimized background regimen; this was not required in cohort one.