prepared to choose (ptc) is an implementation study of the delivery of cabotegravir long-acting, an injectable pre-exposure prophylaxis (prep) option for hiv prevention. injectable prep will be offered alongside oral and vaginal ring prep from within a real-world context in cape town, south africa.

Conditions: HIV Infection; Sexual and Reproductive Health

Summary: the goal of this clinical trial is to offer adolescents and young people in cape town, south africa different hiv pre-exposure prophylaxis (prep) products and describe how they use these products over an 18-month period. the study has both clinical and implementation primary aims. the primary clinical aim is short and long-term persistence on prep. persistence is defined as the length of time that a participant shows continuous use of a prep product as intended, without stopping prep or switching to another prep product. the primary implementation aim involves the determination of factors that either enable or serve as a barrier to prep uptake and continuation. participants will be offered a choice between three antiretroviral-containing prep products: (1) a tenofovir-based oral tablet that needs to be taken daily; (2) a vaginal ring containing dapivirine that provides hiv protection for up to one month; and (3) an intramuscular injection containing cabotegravir that provides hiv protection for up to two months. participants will be able to use the same product throughout the study, switch between products, or stop and restart on prep at any point. the study will be offered from two study sites: the first is a mobile clinic that rotates on a fixed schedule across the study area and the second is a fixed-location government primary healthcare clinic. the study will be open to confirmed hiv-negative individuals, including adolescent girls and young women (aged 15-29 years), young gender and sexually diverse populations aged 15-29 years (including men who have sex with men, transgender people, and non-binary people), and their collective sexual partners (including heterosexual, cisgender men) of any age.

the prepared to choose (ptc) study seeks to describe patterns of persistence on hiv pre-exposure prophylaxis (prep) products, individually and overall, amongst a cohort of south african adolescents and youth when offered a choice between prep products in real-world public health facility and mobile clinic settings. the study will further seek to understand implementation barriers and enablers in prep adoption (decision to use any prep product), initiation (first dose of any prep product), and persistence amongst both prep users (adolescents and youth) and prep providers (healthcare providers). this study will utilise a prospective cohort design that recruits 1800 adolescents and young people, specifically adolescent girls and young women, including pregnant and lacting women (15-29 years), young male key populations including men who have sex with men and male sex workers (15-29 years), and their collective intimate male partners (any age). participants will be invited to choose to initiate on one of three types of prep (injectable, oral, or vaginal ring prep). participants will be able to use the same product throughout the study, switch between products, or stop and restart on prep at any point. participants will be followed for 7 months to meet the primary outcome of short-term persistence and for a further 18 months to meet the secondary outcome of long-term persistence. persistence will be defined as the continuous use of the selected product as intended with (a) \<7 day gap and (b) \<28 day gap in prep availability for daily dosing (oral prep), vaginal ring insertion, or subsequent injection. the 7-day window aligns with previous trial definitions of on-time dosing while the 28-day window aligns with pragmatic definitions of on-time dosing for prep in the south african context. the three products available will include: (1) a tenofovir-based oral tablet that needs to be taken daily and is provided as a 30-day supply of oral tablets; (2) a intra-vaginal silicone ring containing slow-release dapivirine that provides hiv protection for up to 28 days; and (3) an intramuscular injection containing cabotegravir that provides hiv protection for up to two months. the study will aim to recruit up to 900 participants that initiate on injectable prep, up to 600 participants that initiate on oral prep, and up to 300 participants that initiate on vaginal ring prep. prep choice counselling will be co-created with prep providers and young prep users (members of an existing prep-orientated youth reference group) and delivered by trained, adolescent-friendly hiv counsellors. prep will be administered by nimart trained (nurse initiated management of anti-retroviral therapy) nurses at two clinical sites: a stationary government primary health care facility and a mobile clinic service that rotates on a fixed schedule through the study area. participants will initiate at a single site but remain eligible to receive subsequent product refills/doses at the other site if desired.

Eligibility criteria:
inclusion criteria: * all participants must be hiv negative at baseline * all participants must have a body weight ¬\> 35kg at baseline * all participants must be older than 15 years. specific age criteria will be applied to certain population groups. * all participants must be currently resident in the study area * all participants must be able to provide written, informed voluntary consent to partake in the study and willing and able to receive an injectable pre-exposure prophylaxis (prep) product exclusion criteria: * confirmed hiv-positive test result and/or signs and symptoms of an acute hiv infection * clinical conditions contraindicated for the chosen prep product as per sahpra regulations, including use of known contraindicated medications. * allergy to any of the study products * do not spend a reasonable amount of time in the study area as residents, for school, or work, or are otherwise unable to participate in clinical or study visits for geographical reasons, according to the site investigator * medical, social or other condition that, in the opinion of the site investigator, would interfere with the conduct of the study or safety of the participant (e.g., provided by self-report, or found upon medical history and examination or in available medical records) * current enrolment in another hiv prevention clinical trial that in the opinion of the site investigator, would interfere with the conduct of the study or safety of the participant (as verified by registration on the south african medical research council biometric co-enrolment prevention system).

Keywords: hiv prevention pre-exposure prophylaxis injectable prep adolescents and young people south africa cabotegravir long-acting prep choice