Baricitinib for Reduction of HIV – CNS

Description

HIV infection is controllable with antiretroviral therapy (ART), but ART cannot eliminate HIV reservoirs. Thus, there is no available cure for HIV. There is a large and growing body of evidence that the central nervous system (CNS) is an HIV reservoir site and a barrier to HIV eradication. HIV DNA is commonly found in brain from people with HIV (PWH) on suppressive ART. HIV genetic compartmentalization occurs in both the brain and CSF, showing that CNS HIV is distinct from peripheral sources such as blood. Multiple studies have demonstrated that CSF HIV RNA can be detected at very low levels during suppressive ART. A study from the AIDS Clinical Trials Group (ACTG) found HIV DNA in CSF cells from approximately 50% of PWH on suppressive ART, a finding that was associated with neurocognitive impairment. The study team’s group recently demonstrated a significant advance in quantitating HIV from the CSF. Specifically, CSF cell associated HIV RNA was quantifiable in 90% and CSF HIV DNA was quantifiable in 80% of PWH on suppressive ART. Based on these multiple lines of evidence that the CNS is an HIV reservoir, more research is needed on therapies that have the potential to target the CNS reservoir.

The study team has performed extensive pre-clinical and clinical work on the Janus Kinase (Jak 1/2) inhibitor drug class for viral infections. This includes work on ruxolitinib and baricitinib, two FDA approved orally bioavailable agents for myelofibrosis and polycythemia vera (ruxolitinib) as well as rheumatoid arthritis (baricitinib). The investigators have evaluated their potential to target HIV in the CNS in vitro, ex vivo, and in vivo Specifically, the study team has demonstrated that these agents block HIV replication and infection in key CNS cells, reduce the lifespan of HIV CNS reservoirs, and block reservoir reseeding. In vivo, the study team has shown in the murine model that baricitinib decreases CNS HIV and reverses behavioral abnormalities associated with HIV, which correlates with reversal of phenotypic markers of brain inflammation. This has also demonstrated that baricitinib reaches therapeutic CNS concentrations in the rhesus macaque model (including in brain parenchyma) as well as in humans. In a recently published multi-site Phase 2a ACTG-sponsored study with ruxolitinib (A5336, n = 60),the research group demonstrated that ruxolitinib is safe, well-tolerated, and reduces key markers of immune activation. New data that ruxolitinib decreased the peripheral HIV reservoir in a subset of A5336 participants provides even more evidence for this drug class to be included in eradication strategies. However, A5336 did not have any CNS assessments. The investigators now propose to study baricitinib, one of the most promising Jak 1/2 inhibitors with once daily dosing, renal clearance, and a more favorable safety/ pharmacokinetic profile, as a therapy to decrease the HIV CNS reservoir in PWH with durable virologic suppression on ART.