Breakthrough HIV-1 infection in setting of cabotegravir for HIV pre-exposure prophylaxis.

OBJECTIVES: We describe the first case of HIV-1 infection in the setting of long-acting injectable cabotegravir (CAB-LA) for HIV pre-exposure prophylaxis (PrEP) to occur in the real world.

DESIGN: Case report.

METHODS: Electronic medical records were reviewed to assess patient history and CABLA administration details. Plasma 4th generation HIV-1/2 Ag/Ab combination immunoassay and HIV-1 RNA quantitative PCR were performed at each injection visit.

RESULTS: We report a 28-year-old gender diverse person assigned male at birth who acquired HIV-1 infection 91 days after transitioning from tenofovir alafenamideemtricitabine (TAF/FTC) to CAB-LA despite on-time dosing and appropriate laboratory monitoring.

CONCLUSIONS: This patient's history suggests HIV infection despite on-time and appropriate CAB-LA injections. To our knowledge, this is the first case of CAB-LA PrEP failure outside the setting of a clinical trial and highlights diagnostic and management challenges that may occur with such breakthrough infections.