urmc-099 and HIV-Infections

During studies to extend the half-life of crystalline nanoformulated antiretroviral therapy (nanoART) the mixed lineage kinase-3 inhibitor URMC-099, developed as an adjunctive neuroprotective agent was shown to facilitate antiviral responses. Long-acting ritonavir-boosted atazanavir (nanoATV/r) nanoformulations co-administered with URMC-099 reduced viral load and the numbers of HIV-1 infected CD4+ T-cells in lymphoid tissues more than either drug alone in infected humanized NOD/SCID/IL2Rγc-/- mice. The drug effects were associated with sustained ART depots. Proteomics analyses demonstrated that the antiretroviral responses were linked to affected phagolysosomal storage pathways leading to sequestration of nanoATV/r in Rab-associated recycling and late endosomes; sites associated with viral maturation. URMC-099 administered with nanoATV induced a dose-dependent reduction in HIV-1p24 and reverse transcriptase activity. This drug combination offers a unique chemical marriage for cell-based viral clearance. From the Clinical Editor: Although successful in combating HIV-1 infection, the next improvement in antiretroviral therapy (nanoART) would be to devise long acting therapy, such as intra-cellular depots. In this report, the authors described the use of nanoformulated antiretroviral therapy given together with the mixed lineage kinase-3 inhibitor URMC-099, and showed that this combination not only prolonged drug half-life, but also had better efficacy. The findings are hoped to be translated into the clinical setting in the future.

Topics: Animals; Anti-Retroviral Agents; Antiretroviral Therapy, Highly Active; Atazanavir Sulfate; Drug Therapy, Combination; HIV Infections; HIV-1; Humans; MAP Kinase Kinase Kinases; Mice; Mice, SCID; Mitogen-Activated Protein Kinase Kinase Kinase 11; Nanocapsules; Protein Kinase Inhibitors; Pyridines; Pyrroles; Treatment Outcome

Inhibition of mixed lineage kinase 3 (MLK3) is a potential strategy for treatment of Parkinson's disease and HIV-1 associated neurocognitive disorders (HAND), requiring an inhibitor that can achieve significant brain concentration levels. We report here URMC-099 (1) an orally bioavailable (F = 41%), potent (IC50 = 14 nM) MLK3 inhibitor with excellent brain exposure in mouse PK models and minimal interference with key human CYP450 enzymes or hERG channels. The compound inhibits LPS-induced TNFα release in microglial cells, HIV-1 Tat-induced release of cytokines in human monocytes and up-regulation of phospho-JNK in Tat-injected brains of mice. Compound 1 likely functions in HAND preclinical models by inhibiting multiple kinase pathways, including MLK3 and LRRK2 (IC50 = 11 nM). We compare the kinase specificity and BBB penetration of 1 with CEP-1347 (2). Compound 1 is well tolerated, with excellent in vivo activity in HAND models, and is under investigation for further development.

Topics: Administration, Oral; Animals; Area Under Curve; Biological Availability; Blood-Brain Barrier; Brain; Carbazoles; Cells, Cultured; Cognition Disorders; Drug Discovery; HIV Infections; Humans; JNK Mitogen-Activated Protein Kinases; Male; MAP Kinase Kinase Kinases; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase Kinase Kinase 11; Models, Chemical; Molecular Structure; Monocytes; Phosphorylation; Protein Kinase Inhibitors; Pyridines; Pyrroles; tat Gene Products, Human Immunodeficiency Virus; Tumor Necrosis Factor-alpha

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) is a significant source of disability in the HIV-infected population. Even with stringent adherence to anti-retroviral therapy, >50% of patients living with HIV-1 will develop HAND (Heaton et al., 2010). Because suppression of viral replication alone is not enough to stop HAND progression, there is a need for an adjunctive neuroprotective therapy in this population. To this end, we have developed a small-molecule brain-penetrant inhibitor with activity against mixed-lineage kinase 3 (MLK3), named URMC-099. MLK3 activation is associated with many of the pathologic hallmarks of HAND (Bodner et al., 2002, 2004; Sui et al., 2006) and therefore represents a prime target for adjunctive therapy based on small-molecule kinase inhibition. Here we demonstrate the anti-inflammatory and neuroprotective effects of URMC-099 in multiple murine and rodent models of HAND. In vitro, URMC-099 treatment reduced inflammatory cytokine production by HIV-1 Tat-exposed microglia and prevented destruction and phagocytosis of cultured neuronal axons by these cells. In vivo, URMC-099 treatment reduced inflammatory cytokine production, protected neuronal architecture, and altered the morphologic and ultrastructural response of microglia to HIV-1 Tat exposure. In conclusion, these data provide compelling in vitro and in vivo evidence to investigate the utility of URMC-099 in other models of HAND with the goal of advancement to an adjunctive therapeutic agent.

Topics: Animals; Bone Marrow Transplantation; Cell Line, Transformed; Cells, Cultured; CX3C Chemokine Receptor 1; Cytokines; Disease Models, Animal; Embryo, Mammalian; Gene Products, tat; Green Fluorescent Proteins; Hippocampus; HIV Infections; HIV-1; Humans; Inflammation; MAP Kinase Kinase Kinases; Mice; Mice, Transgenic; Microscopy, Immunoelectron; Mitogen-Activated Protein Kinase Kinase Kinase 11; Neuroprotective Agents; Phagocytosis; Phosphorylation; Pyridines; Pyrroles; Rats; Receptors, Chemokine; Signal Transduction; Statistics, Nonparametric; tat Gene Products, Human Immunodeficiency Virus; Time Factors; Transfection