Early triple combination therapy blocked viral rebound. CytoDyn's (CYDY) clinical trial candidate, leronlimab (PRO 140), a humanized IgG4 antibody, blocks the C-C chemokine receptor 5 (CCR5), which HIV uses to enter CD4+ T cells. Researchers administered a combination of antiretroviral therapy (ART), broadly neutralizing antibodies PGT121-LS and VRC07-523-LS, and leronlimab to 4-week-old red rhesus monkeys infected with SHIV-SF162P3, starting 72 hours post-infection. After 27 weeks, no viral rebound or detectable lymphoid and cell-associated viral DNA was observed in the eight animals in the triple combination group that discontinued ART. This is a key finding, as it demonstrates a preclinical effect of blocking reservoir formation shortly after infection, rather than treating established chronic HIV. The synergistic mechanism is more important than individual components. Two animals receiving ART and neutralizing antibodies alone rebounded rapidly after treatment discontinuation, and four of the six animals receiving ART and leronlimab experienced viral rebound within 10 weeks. In contrast, the eight animals receiving the combination of CCR5 entry blockade, viral envelope neutralization, and replication inhibition maintained long-term viral suppression. PGT121-LS targets the V3 glycan of the HIV envelope protein gp120, and VRC07-523-LS targets the CD4-binding site, so there is no overlap in the targets with leronlimab. As a result, this data demonstrates the potential for a complementary combination strategy to suppress the viral reservoir, rather than proving leronlimab's efficacy as a standalone cure. Separate validation is needed for human development. Leronlimab has undergone Phase 3 clinical trials as a combination therapy for patients with multi-drug resistant HIV, but it is not an approved product. The FDA issued a refuse-to-file letter for the Biologics License Application (BLA) in July 2020, and CytoDyn withdrew the BLA in October 2022, citing data management issues at the clinical trial site. The partial clinical hold on the HIV program, imposed in March 2022, was lifted on February 27, 2024, but this infant monkey study has not led to a pivotal clinical trial or approval for humans. Separate studies on dosage, safety, and treatment discontinuation are needed in adults with chronic infection, as they have larger established reservoirs and greater viral diversity. The standard of care in the commercial HIV market is already high. The standard of care is a once-daily combination ART, such as Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) from Gilead Sciences (GILD), which generated $20.8 billion in HIV sales in 2025. A long-acting competitor, Cabenuva (cabotegravir/rilpivirine) from ViiV Healthcare, was approved by the FDA on January 21, 2021, and Selzentry (maraviroc), a CCR5 antagonist, was approved on August 6, 2007. Trogarzo (ibalizumab-uiyk), an anti-CD4 antibody for multi-drug resistant patients, was approved on March 6, 2018, setting a commercial precedent for antibody therapy. The value of leronlimab will be fully realized when it can replicate sustained viral remission without ART in humans, rather than competing on dosing convenience. The key variable for corporate value is the design of a confirmatory study and an early clinical trial in humans to restore development credibility, which was damaged by the FDA's refusal to file the BLA in 2020 and the subsequent withdrawal in 2022.