Managing HIV in the extreme: Viral load and drug monitoring in a patient with BMI > 60 on long-acting cabotegravir/rilpivirine therapy.

This case describes the use of long-acting injectable (LA-I) cabotegravir/rilpirivine (CAB/RPV) therapy in a morbidly obese person (body mass index [BMI] = 62 kg m-2) living with HIV without sustained viral load (VL) suppression after historic poor adherence to daily oral antiretroviral therapy. Increased BMI > 30 kg m-2 is a known risk factor for VL rebound with CAB/RPV failures; thus, RPV therapeutic drug monitoring (TDM) was followed with regularly scheduled VL assessments. Based on TDM concentrations, monthly dose titration from standard CAB/RPV 400 mg/600 mg to 600 mg/900 mg increased trough concentrations with VL suppression (<200 copies mL-1) maintained. TDM may be an additional tool in this population with high BMI values to optimize CAB/RPV dosing strategies as data accumulate in this high-risk group for viral rebound with LA-I therapy.