you will attend a baseline appointment where personal health information, a physical exam, and blood tests will be performed. the blood tests will include measurement of hiv viral load (the amount of hiv virus in your blood) and cd4+ t‑cell count (a measure of immune system health).

after the baseline assessments, you will be randomly assigned to one of two treatment groups.

if you are assigned to the long‑acting antibody group, you will receive three injections on the same day: a subcutaneous injection of lenacapavir 600 mg, an intravenous infusion of teropavimab 3400 mg, and an intravenous infusion of zinlirvimab 3400 mg. these medications are given as a single dose that will provide protection for approximately six months.

if you are assigned to the comparator group, you will receive two intramuscular injections on the same day: cabotegravir 3400 mg and rilpivirine 900 mg. these injections are scheduled to be repeated every eight weeks.

for the antibody group, you will return for the same set of three injections every 24 weeks (approximately twice a year) for the duration of the study.

for the comparator group, you will receive the two intramuscular injections every eight weeks (about every two months) for the duration of the study.

you will attend clinic visits at weeks 4, 12, 24, 26, 52, 72, 92, and 104. at each visit, blood will be drawn to check hiv viral load, cd4+ t‑cell count, and routine safety labs. you will also be asked about any side effects or new health problems.

the study staff will record any adverse events (any unwanted medical problem that occurs during the study) and will assess whether the study medication needs to be adjusted or stopped.

additional blood samples will be taken at weeks 26, 52, and 104 to measure the levels of lenacapavir, teropavimab, and zinlirvimab in your bloodstream. this helps determine how the drugs are maintained over time.

at week 104, you will complete the final study visit. this visit includes the same laboratory assessments as earlier visits, a review of any adverse events that occurred during the study, and a discussion of the overall results.

if a serious adverse event occurs or if you develop a condition that makes continued use of the study medication unsafe, the study medication may be stopped before the scheduled end of the study. you will be monitored closely and provided appropriate medical care.