Ezurpimtrostat hydrochloride  (Synonyms: GNS561 hydrochloride)

Ezurpimtrostat hydrochloride (GNS561 hydrochloride) is an orally active PPT1 inhibitor, autophagy inhibitor, immunomodulator, anti-inflammatory agent, and anticancer agent. Ezurpimtrostat hydrochloride inhibits PPT1, dysregulates lysosomal function, redistributes mTOR, and induces apoptosis. Ezurpimtrostat hydrochloride reduces IFN‑α, CRP, immune complex deposition, and SARS‑CoV‑2 viral load. Ezurpimtrostat hydrochloride can be used for the study of systemic lupus erythematosus, SARS‑CoV‑2, hepatocellular carcinoma, fibrosis, and related disorders^[1][2][3][4].

Ezurpimtrostat (2-6 μM; 24 h) hydrochloride blocks late-stage autophagic flux in uninfected Vero E6 cells, with a dose-dependent increase in LC3-II and p62 accumulation^[2].
Ezurpimtrostat (2 h pre-treatment, 24 h infection incubation) hydrochloride Ezurpimtrostat potently inhibits SARS-CoV-2 replication in Vero E6 and Calu-3 cells, with EC₅₀ values of 0.04 μM, 0.006 μM, and 1.1 μM, and CC₅₀ values of 8.19 μM, 2 μM, and 4.6 μM against the IHUMI-6 and USA-WA1/2020 strains^[2].
Ezurpimtrostat (1 μM; 2 h pre-treatment, 48 h infection incubation) hydrochloride enhances LC3B cluster formation and signal in SARS-CoV-2-infected Vero E6 cells at 1 μM, and colocalizes with SARS-CoV-2 in LAMP2-positive lysosomes, indicating modulation of the autophagy pathway during viral infection^[2].
Ezurpimtrostat (4 μM; 2 h pre-treatment, 24 h infection incubation) hydrochloride treatment at 4 μM increases autophagic vacuole volume and induces multilamellar body formation in SARS-CoV-2-infected Vero E6 cells, indicating disruption of autophagosome-lysosome fusion^[2].
Ezurpimtrostat (72 h) hydrochloride potently inhibits the viability of a broad panel of human cancer cell lines and primary HCC cells^[3].
Ezurpimtrostat (0-4 μM; 6-48 h) hydrochloride induces caspase-dependent apoptotic cell death in HepG2 cells in vitro in a dose- and time-dependent manner, with significant caspase activation observed after 24 hours of treatment^[3].
Ezurpimtrostat (10 μM GNS561D; 90 min) hydrochloride is a lysosomotropic agent that accumulates in HepG2 cell lysosomes, and its antitumor activity in these cells is dependent on this lysosomal localization^[3].
Ezurpimtrostat (0.5-10 μM; 1-24 h) hydrochloride modulates lysosomal function in HepG2 cells by inducing lysosomal enlargement, lysosomal unbound Zn²⁺ accumulation, impaired cathepsin maturation and activity, and blockage of autophagic flux^[3].
Ezurpimtrostat (0.5-100 μM; 3-24 h) hydrochloride binds to and inhibits PPT1 in HepG2 cells, leading to MTOR displacement from the lysosomal membrane and autophagic flux inhibition; its antitumor activity is partially mediated by PPT1 inhibition, with additional contributing mechanisms^[3].
Ezurpimtrostat (1-3 μM; 24-48 h) hydrochloride induces lysosomal membrane permeabilization in HepG2 cells, leading to cathepsin release and partially CTSB- and CTSD-dependent apoptotic cell death^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Ezurpimtrostat (GNS561) (15 mg/kg; p.o.; daily; 6 months (preventive); 3 months (therapeutic)) hydrochloride reduces systemic lupus erythematosus-related clinical manifestations, autoimmunity markers, and inflammatory profiles^[1].
Ezurpimtrostat (50 mg/kg; p.o.; once daily; 24 hours pre-infection to 7 days post-infection) hydrochloride disrupts the autophagy pathway in SARS-CoV-2-infected K18-hACE2 mice and reduces lung viral load^[2].
Ezurpimtrostat (50 mg/kg; p.o.) hydrochloride reduces hepatocellular carcinoma tumor volume by 37.1% and tumor weight by 34.4%, and decreases serum AFP levels significantly at days 21 and 28 post inoculation in a BALB/c nude mouse orthotopic xenograft model^[3].
Ezurpimtrostat (15 mg/kg/day; p.o.; daily; 6 weeks) hydrochloride reduces hepatocellular carcinoma tumor progression by 33%, decreases mean tumor size and tumor nodule count, and lowers CCND1 and MKI67 staining in a DEN-induced cirrhotic Fischer 344 rat HCC model^[3].
Ezurpimtrostat (15-50 mg/kg/day; p.o.; daily; 21-28 days) hydrochloride shows high liver tropism in rats, with the highest accumulation in liver, stomach, and lung, and limited crossing of the blood-brain and blood-testis barriers^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

459.45

C₂₅H₃₂Cl₂N₄

1914148-73-4

Solid

Off-white to light yellow

CC(NC1CCN(C2=CC(NCC3=CC=C(Cl)C=C3)=NC4=CC=CC=C24)CC1)(C)C.[H]Cl

Room temperature in continental US; may vary elsewhere.

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

• [1]. Toumi E, et al. GNS561 (ezurpimtrostat), a small basic lipophilic molecule, prevents lupus phenotype in a pristane-induced lupus mouse model. Br J Pharmacol. 2025;182(16):3786-3799.  [Content Brief]

  [2]. Bestion E, et al. GNS561 Exhibits Potent Antiviral Activity against SARS-CoV-2 through Autophagy Inhibition. Viruses. 2022;14(1):132. Published 2022 Jan 12.  [Content Brief]

  [3]. Brun S, et al. GNS561, a clinical-stage PPT1 inhibitor, is efficient against hepatocellular carcinoma via modulation of lysosomal functions. Autophagy. 2022;18(3):678-694.  [Content Brief]

  [4]. Halfon P, et al. Substituted 2,4 diamino-quinoline as new medicament for fibrosis, autophagy and cathepsins b (ctsb), l (ctsl) and d (ctsd) related diseases, EP, EP3620164A1, 2020-03-11.