Evaluation of Trimer 4571 Therapeutic Vaccination in Adults Living With HIV on Suppressive Antiretroviral Therapy

The immune system is composed of special cells, proteins, tissues, and organs that protect against germs and microorganisms and is the body's defense against infections. Antibodies are a type of protein that helps the body fight infection and are usually made by a person's own immune system. A type of antibody that can recognize and block many types of HIV from entering healthy cells are called broadly neutralizing antibodies, or 'bnAbs', and may also activate other immune cells to help destroy HIV-infected cells. Research has shown that people with HIV who develop bnAbs against the virus are better able to control the infection. While the immune systems of some people with HIV show signs of early bnAb production, only a small percentage of people with HIV naturally develop bnAbs. Approximately 32 participants will be sequentially enrolled and randomized 3:1 by chance like rolling dice to receive either the Trimer 4571 vaccine or a placebo vaccine that does not contain Trimer 4571. Participants will be asked to attend 11 study visits over a period of approximately 50 weeks and receive 3 doses of their assigned study vaccine: one at Entry, one at Week 8 and one at Week 20. Researchers will compare the results from participants who get the Trimer 4571 vaccine with results from participants who get the placebo vaccine. Participants, the researchers and the clinic staff will not know which vaccine participants are getting. After Week 20, participants will be followed for 24 additional weeks with study visits and tests to monitor their health and safety and to see how the study vaccine affects the immune system and the virus.