A pilot study to examine the tolerability and antiviral activity of switching to Biktarvy tablets taken once daily compared to baseline over 48 weeks in HIV-1 infected antiretroviral therapy (ART) experienced participants aged 55 years and older who are virologically suppressed on a current antiretroviral regimen (CAR) which includes a Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) and /or a Protease Inhibitor (PI).