In vivo effects of the alpha-synuclein misfolding inhibitor minzasolmin supports clinical development in Parkinson's disease.

Direct targeting of alpha-synuclein (ASYN) has emerged as a disease-modifying strategy for Parkinson's disease and other synucleinopathies which is being approached using both small molecule compounds and ASYN-targeted biologics. Minzasolmin (UCB0599) is an orally bioavailable and brain-penetrant small molecule ASYN misfolding inhibitor in clinical development as a disease-modifying therapeutic for Parkinson's disease. Herein the results of preclinical evaluations of minzasolmin that formed the basis for subsequent clinical development are described. Pharmacokinetic evaluations of intraperitoneal 1 and 5 mg/kg minzasolmin in wildtype mice revealed parallel and dose-proportional exposures in brain and plasma. Three-month administration studies in the Line 61 transgenic mouse model of PD were conducted to measure ASYN pathology and other PD-relevant endpoints including markers of CNS inflammation, striatal DAT labeling and gait. Reductions in ASYN pathology were correlated with improved aspects of gait and balance, reductions in CNS inflammation marker abundance, and normalized striatal DAT levels. These findings provide support for human dose determinations and have informed the translational strategy for clinical trial design and biomarker selection for the ongoing clinical studies of minzasolmin in patients living with early-stage Parkinson's disease (ClinicalTrials.gov ID: NCT04658186; EudraCT Number 2020-003265).

Phase 1/1b Studies of UCB0599, an Oral Inhibitor of α-Synuclein Misfolding, Including a Randomized Study in Parkinson's Disease.

BACKGROUND: Parkinson's disease (PD) and its progression are thought to be caused and driven by misfolding of α-synuclein (ASYN). UCB0599 is an oral, small-molecule inhibitor of ASYN misfolding, aimed at slowing disease progression. OBJECTIVE: The aim was to investigate safety/tolerability and pharmacokinetics (PK) of single and multiple doses of UCB0599. METHODS: Safety/tolerability and PK of single and multiple doses of UCB0599 and its metabolites were investigated in two phase 1 studies in healthy participants (HPs), where food effect and possible interaction with itraconazole (ITZ) were assessed (UP0030 [randomized, placebo-controlled, dose-escalation, crossover study, N = 65] and UP0078 [open-label study, N = 22]). Safety/tolerability and multi-dose PK of UCB0599 were subsequently investigated in a phase 1b randomized, double-blind, placebo-controlled study of participants with PD (UP0077 [NCT04875962], N = 31). RESULTS: Across all studies, UCB0599 displayed rapid absorption with linear, time-independent PK properties; PK of multiple doses of UCB0599 were predictable from single-dose exposures. No notable food-effect was observed; co-administration with ITZ affected UCB0599 disposition (maximum plasma concentration and area under the curve increased ~1.3- and ~2 to 3-fold, respectively) however, this did not impact the safety profile. Hypersensitivity reactions were reported in UP0030 (n = 2) and UP0077 (n = 2). Treatment-related adverse events occurred in 43% (UCB0599), and 30% (placebo) of participants with PD were predominantly mild-to-moderate in intensity and were not dose related. CONCLUSIONS: Seventy-three HPs and 21 participants with PD received UCB0599 doses; an acceptable safety/tolerability profile and predictable PK support continued development of UCB0599 for the slowing of PD progression. A phase 2 study in early-stage PD is underway (NCT04658186). © 2022 UCB Pharma. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Anti-inflammatory drug therapy alters beta-amyloid processing and deposition in an animal model of Alzheimer's disease.

Alzheimer's disease (AD) is characterized by a microglial-mediated inflammatory response elicited by extensive amyloid deposition in the brain. Nonsteroidal anti-inflammatory drug (NSAID) treatment reduces AD risk, slows disease progression, and reduces microglial activation; however, the basis of these effects is unknown. We report that treatment of 11-month-old Tg2576 mice overexpressing human amyloid precursor protein (APP) with the NSAID ibuprofen for 16 weeks resulted in the dramatic and selective reduction of SDS-soluble beta-amyloid (Abeta)42, whereas it had smaller effects on SDS-soluble Abeta40 levels. Ibuprofen treatment resulted in 60% reduction of amyloid plaque load in the cortex of these animals. In vitro studies using APP-expressing 293 cells showed that ibuprofen directly affected APP processing, specifically reducing the production of Abeta42. Ibuprofen treatment resulted in a significant reduction in microglial activation in the Tg2576 mice, as measured by CD45 and CD11b expression. NSAIDs activate the nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARgamma); however, a potent agonist of this receptor, pioglitazone, only modestly reduced SDS-soluble Abeta levels and did not affect amyloid plaque burden or microglia activation, indicating that PPARgamma activation is not involved in the Abeta lowering effect of NSAIDs. These data show that chronic NSAID treatment can reduce brain Abeta levels, amyloid plaque burden, and microglial activation in an animal model of Alzheimer's disease.

Oxidative dimer formation is the critical rate-limiting step for Parkinson's disease alpha-synuclein fibrillogenesis.

Intraneuronal deposition of alpha-synuclein as fibrils and oxidative stress are both implicated in the pathogenesis of Parkinson's disease. We found that the critical rate-limiting step in nucleation of alpha-synuclein fibrils under physiological conditions is the oxidative formation and accumulation of a dimeric, dityrosine cross-linked prenucleus. Dimer formation is accelerated for the pathogenic A30P and A53T mutant alpha-synucleins, because of their greater propensity to self-interact, which is reflected in the smaller values of the osmotic second virial coefficient compared to that of wild-type synuclein. Our finding that oxidation is an essential step in alpha-synuclein aggregation supports a mechanism of Parkinson's disease pathogenesis in which the separately studied pathogenic factors of oxidative stress and alpha-synuclein aggregation converge at the critical step of alpha-synuclein dimer formation.