Selective Inhibitors of G2019S-LRRK2 Kinase Activity

Abstract

Pathogenic variants in the leucine-rich repeat kinase 2 (LRRK2) gene have been identified that increase the risk for developing Parkinson's disease in a dominantly inherited fashion. These pathogenic variants, of which G2019S is the most common, cause abnormally high kinase activity, and compounds that inhibit this activity are being pursued as potentially disease-modifying therapeutics. Because LRRK2 regulates important cellular processes, developing inhibitors that can selectively target the pathogenic variant while sparing normal LRRK2 activity could offer potential advantages in heterozygous carriers. We conducted a high-throughput screen and identified a single selective compound that preferentially inhibited G2019S-LRRK2. Optimization of this scaffold led to a series of novel, potent, and highly selective G2019S-LRRK2 inhibitors.

The tale of proteolysis targeting chimeras (PROTACs) for Leucine‐Rich Repeat Kinase 2 (LRRK2)

“…The data taken together with our results, show that the selection of LRRK2 inhibitors is crucial for the development of degraders. Additionally, very recently, a high‐throughput screen resulted in the discovery of a small molecule, which showed remarkable selectivity for G2019S‐LRRK2, the most common LRRK2 pathogenic mutation [24] . This could be an interesting starting point for future studies of selective G2019S‐LRRK2 degraders.…”

“…Pomalidomide was also used in an acylation reaction with 2-chloroacetyl chloride to obtain the intermediate (22), which with a substitution reaction led to intermediate (23). In a similar way, the condensation of 4-fluoroisobenzofuran-1,3dione with 3-aminopiperidine-2,6-dione was performed to obtain the fluoro-substituted imide (24), which underwent a nucleophilic aromatic substitution with linear Boc-protected diamines to obtain intermediates (25) and (26).…”

Differential Inhibition of LRRK2 in Parkinson's Disease Patient Blood by a G2019S Selective LRRK2 Inhibitor

“…These data evaluating the impact of a G2019S selective inhibitor in a system utilizing endogenous levels of LRRK2 in humans critically extends the findings from an artificial overexpression system. 15 Though the therapeutic rationale for inhibiting pathogenic LRRK2 kinase activity is compelling, it is also complicated by concerns over on-target safety liabilities associated with the loss of normal WT LRRK2 activity. 16,17 In a study evaluating three structurally distinct LRRK2 inhibitors, only partial inhibition of LRRK2 in the lung in macaque monkeys could be sustained without inducing on-target pathological phenotypes in type II pneumocytes.…”

“…Conversely, both the downstream substrate phosphorylation of Rab10 at Thr73 (pThr73 Rab10) and an established indirect LRRK2 inhibitor sensitive phosphorylation site at Ser935 (pSer935 LRRK2) have been utilized as target modulation biomarkers for therapeutic trials of LRRK2 kinase inhibitors. [11][12][13] The aim of the present study was to compare the biomarker sensitivity of a novel, highly selective G2019S LRRK2 inhibitor (EB-42168), shown to inhibit G2019S LRRK2 100-fold more potently than wild-type (WT) LRRK2 (Garofalo A., et al 2020), with a nonselective LRRK2 inhibitor (MLi-2). 14 Inhibition of pSer935 LRRK2 and pThr73 Rab10 were compared in an ex vivo assay of human peripheral blood mononuclear cells (PBMCs) isolated from fresh blood samples from subjects who were homozygous, heterozygous, or noncarriers for the G2019S LRRK2 variant.…”

The development of inhibitors of leucine‐rich repeat kinase 2 (LRRK2) as a therapeutic strategy for Parkinson's disease: the current state of play

“…One recent development that is worthy of mention, however, is the discovery of ATP-competitive LRRK2 inhibitors that exhibit selectivity for the pathogenic G2019S LRRK2 variant over wild-type LRRK2 (Garofalo et al, 2020). Via compound library screening followed by in silico docking analysis and systematic chemical modifications, Garofalo and colleagues identified a number of indazole molecules displaying selectivity for G2019S (Garofalo et al, 2020). The most selective compound was reported to have a >300x greater potency in cellular assays and >200x greater potency in vitro.…”