Inclusion Criteria:  HIV-1-infected Aged 12-19 years Aware of HIV status Body weight ≥35Kg On ART consisting of 2NRTI and a third agent On ART for ≥1 year with no previous regimen change for treatment failure* Virologically suppressed with all HIV-1 RNA viral loads <50copies/mL¥ in the last 12 months up to and including screening. Additionally, there must be one result <50copies/mL at least 12 months prior to screening and the viral load at trial screening must be <50 copies/mL Written informed consent provided by participant (if aged 18 to 19 years) and/or carer/legal guardian (if participant aged 12 to 17 years) as appropriate Written informed assent in participants aged 12 to 17 years  Females who are sexually active must be willing to adhere to highly effective methods of contraception⌂  Treatment failure includes virological, immunological or clinical failure where regimen has been changed for lack of response to treatment  The screening sample VL must be <50 copies/mL. For samples prior to screening, a diluted sample may be used; if the viral load in the diluted sample is below lower limit of quantification (LLQ), a calculated VL<100 copies/mL is allowed; if the viral load in the diluted sample is equal or above LLQ the calculated VL should be below 50 copies/mL.  Highly effective contraception are injectable, implantable, oral and intrauterine contraceptives which have an expected failure rate <1% per year; in the LA group, must avoid pregnancy for 12 months after the last dose of the CAB and RPV LA  Exclusion Criteria:  Known HIV-2 infection Females who are pregnant or breastfeeding Females who plan to become pregnant during the trial follow-up or are sexually active and are unwilling to avoid pregnancy for the duration of the trial Moderate or high-risk score on the Columbia-Suicide Severity Rating Scale Hepatitis B SAg positive ALT ≥3 x upper limit of normal On treatment for active TB Known contraindication to receipt of dolutegravir, cabotegravir, rilpivirine, emtricitabine/ lamivudine and any formulation of tenofovir Participants determined by the investigator to have a high risk of seizure, including those with unstable or poorly controlled seizure disorder Unwilling or contraindication to receiving injections Contraindication to receiving injectable agents in the buttock area Underlying medical condition (e.g. bleeding disorder; use of warfarin) that in the opinion of the investigator precludes participation Previous randomisation in the BREATHER Plus trial  Known major^ resistance to non-nucleoside reverse transcriptase inhibitors or integrase inhibitors  Major NNRTI and INSTI mutations are those listed in the IAS report (www.iasusa.org/resources/hiv-drug-resistance-mutations/ - which is likely to change over time