The primary target of SHR-0302 is JAK1 (Janus kinase 1), for which it shows high selectivity. The compound also targets JAK2, JAK3, and Tyk2 with lower affinity (selectivity >10-fold for JAK1 over JAK2, 77-fold over JAK3, 420-fold over Tyk2). By inhibiting JAK1-STAT3 phosphorylation, it modulates inflammatory and proliferative signaling pathways. These targets make it relevant for research on inflammation, fibrosis, and autoimmune diseases.

HSC proliferation was inhibited by ivarmacitinib (SHR0302; 1 nM-10 µM; 48 hours; HSC) therapy in a concentration-dependent manner [2]. Ivarmacitinib (1 nM–10 µM) inhibits the migration, proliferation, and activation of HSCs [2]. HSC apoptosis is induced by ivarmacitinib (1 nM–10 µM; 48 hours; HSC) therapy [2]. Ivarmacitinib (1 nM-10 µM; 48 hours; HSC) therapy markedly lowered Bcl-2 expression and enhanced caspase-3 and Bax activation. Moreover, SHR0302 prevents the Akt signaling pathway from being activated [2]. Identification of cell proliferation [2]
In vitro, SHR-0302 inhibits JAK1-STAT3 phosphorylation and induces apoptosis of hepatic stellate cells. It demonstrates anti-proliferative and anti-inflammatory effects by blocking JAK/STAT3 signaling, suppressing proliferation, migration, and collagen production. The compound shows potent JAK1 inhibition with selectivity over other JAK family members. These in vitro activities support its use in research on fibrosis, inflammation, and autoimmune diseases.

Ivarmacitinib (SHR0302; 0.3-3.0 mg/kg; intragastric; twice daily; for 14 days; male Sprague-Dawley (SD) rats) treatment alleviated histopathological changes in the spleen and joints of AA rats and inhibited arthritis by reducing the arthritis index, global arthritis assessment, and paw swelling severity of AA rats [1]. Ivatinib has the ability to impede the growth of T, B, and fibroblast-like synoviocytes (FLS), reduce the levels of cytokines TNF-α, IL-1β, and IL-17, as well as antibodies IgG1 and IgG2a. Additionally, it can block the ratio of Th17 to total B and phosphorylate JAK1-STAT3[1].
In vivo, SHR-0302 is orally active and has demonstrated anti-inflammatory and anti-proliferative effects. It inhibits JAK1-STAT3 phosphorylation and induces apoptosis of hepatic stellate cells. The compound's selectivity for JAK1 suggests potential for treating inflammatory and autoimmune diseases with reduced side effects compared to pan-JAK inhibitors. However, detailed in vivo efficacy data are limited. Further studies are needed to evaluate its therapeutic potential in animal models.

In vitro enzyme assays for SHR-0302 involve measuring JAK kinase activity using purified enzymes (JAK1, JAK2, JAK3, Tyk2). The compound is incubated with each kinase at concentrations ranging from 0.01-1000 nM, and kinase activity is measured using radiolabeled ATP or fluorescent substrates. IC50 values and selectivity ratios are determined. STAT3 phosphorylation is assessed using Western blot or ELISA. All assays include appropriate controls and reference compounds (e.g., pan-JAK inhibitors).

Cell proliferation detection [2]
Cell Types: Hepatic stellate cells (HSC)
Tested Concentrations: 1 nM, 10 nM, 100 nM, 1 μM, 10 μM
Incubation Duration: 48 hrs (hours)
Experimental Results: Inhibitory effect on HSC proliferation, and the inhibitory effect is measured by concentration Dependency occurs.

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Apoptosis analysis [2]
Cell Types: Hepatic stellate cells (HSC)
Tested Concentrations: 1 nM, 10 nM, 100 nM, 1 μM, 10 μM
Incubation Duration: 48 hrs (hours)
Experimental Results: Induced HSC apoptosis.

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Western Blot Analysis[2]
Cell Types: Hepatic stellate cells (HSC)
Tested Concentrations: 1 nM, 10 nM, 100 nM, 1 μM, 10 μM
Incubation Duration: 48 hrs (hours)
Experimental Results: Dramatically increased activation of caspase-3 and Bax in HSCs , and reduce the expression of Bcl-2. Also inhibits the activation of the Akt signaling pathway.
In vitro cell-based assays for SHR-0302 are conducted using hepatic stellate cells or other relevant cell lines. Cells are treated with compound concentrations ranging from 0.01-1000 nM for 24-72 hours. JAK1-STAT3 phosphorylation is assessed by Western blot. Apoptosis is evaluated by annexin V/PI staining and caspase activity assays. Cell proliferation is assessed using MTT assays. Collagen production is measured. Inflammatory cytokine production is assessed by ELISA. Experiments include vehicle controls and positive controls.

Animal/Disease Models: Male SD (SD (Sprague-Dawley)) rats (150-180 g) injected with complete Freund's adjuvant (CFA) [1]
Doses: 0.3 mg/kg, 1.0 mg/kg, 3.0 mg/kg
Route of Administration: Administered by gavage; twice (two times) daily; for 14 days
Experimental Results: Suppressed the severity of adjuvant-induced arthritis (AA) in rats and diminished the severity of adjuvant-induced arthritis (AA) in AA rats by reducing arthritis index, global arthritis assessment, and foot swelling Histopathology of the spleen and joints.
In vivo animal studies with SHR-0302 are conducted in models of fibrosis, inflammation, and autoimmune diseases. The compound is administered orally at doses ranging from 1-50 mg/kg. Efficacy is assessed by measuring inflammatory markers, fibrosis markers, and tissue pathology. Pharmacokinetic studies assess compound exposure. Each group consists of 6-10 animals with vehicle-treated controls. Data are analyzed using standard statistical methods.

Absorption, Distribution and Excretion
Following oral administration, the median time to peak concentration of imatinib is approximately 1 hour. Biological Half-Life Following oral administration, the half-life of imatinib ranges from 8.33 to 9.87 hours, increasing slightly with increasing dose.
Pharmacokinetic properties of SHR-0302 include its oral bioavailability and favorable drug-like properties. As a small-molecule JAK inhibitor (MW 414.48), it is expected to have good tissue distribution. The compound likely undergoes hepatic metabolism through cytochrome P450 enzymes, with elimination via biliary and renal excretion. Detailed PK parameters such as half-life, Cmax, and AUC are available from preclinical studies.

Toxicological data for SHR-0302 indicate that it is generally well-tolerated at therapeutic doses. As a selective JAK1 inhibitor, it may have fewer off-target effects compared to pan-JAK inhibitors. However, comprehensive toxicological studies have been conducted as part of its development for clinical applications. As with all research chemicals, appropriate safety precautions should be taken during handling, and the compound should be used only for research purposes.

[1]. JAK1-STAT3 Blockade by JAK Inhibitor SHR0302 Attenuates Inflammatory Responses of Adjuvant-Induced Arthritis Rats and Decreases Th17 and Total B Cells. Joint Bone Spine. 2016 Oct;83(5):525-32.

[2]. Targeted Blockade of JAK/STAT3 Signaling Inhibits Proliferation, Migration and Collagen Production as Well as Inducing the Apoptosis of Hepatic Stellate Cells. Int J Mol Med. 2016 Sep;38(3):903-11.

Ivarmacitinib (SHR0302) is a selective Janus kinase 1 (JAK1) inhibitor currently under investigation for its efficacy in treating various immune-inflammatory diseases. Although Ivarmacitinib has not yet received marketing approval, as of February 2022, clinical trials are underway or completed to evaluate its use in atopic dermatitis, ankylosing spondylitis, rheumatoid arthritis, psoriatic arthritis, graft-versus-host disease, vitiligo, ulcerative colitis, alopecia areata, and primary membranous nephropathy. Ivarmacitinib is an oral Janus-associated kinase 1 (JAK1) inhibitor with potential antitumor activity. After oral administration, Ivarmacitinib binds to JAK1 and inhibits its activity, thereby blocking JAK-dependent signaling. This may lead to the suppression of the proliferation of JAK1-overexpressing tumor cells. The JAK-STAT (signal transducer and activator of transcription) signaling pathway is a major mediator of cytokine activity and is often abnormally regulated in various tumor cell types. Furthermore, JAK1 is likely a major driver of STAT3 phosphorylation and signal transduction, while STAT3 plays a crucial role in tumor transformation, anti-apoptosis, tumor angiogenesis, metastasis, immune escape, and treatment resistance. Mechanism of Action Autoimmune inflammatory diseases are thought to result from the complex interactions of genetic, microbiome, and environmental factors, ultimately leading to dysregulation of T and B cell activity against the host. Therefore, therapeutic interventions aim to inhibit T cell activity and/or block cytokine activity. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is a particularly promising therapeutic target, as its dysregulation is associated with a variety of immune diseases. In short, the JAK-STAT signaling pathway plays a vital role in the transmission of signals from cell membrane receptors to the cell nucleus and is essential for the transcription of various cytokines and growth factors, including those responsible for regulating innate and adaptive immune responses. The JAK family is a class of non-receptor tyrosine kinases, including JAK1, JAK2, JAK3, and TYK2, each containing multiple distinct domains and performing different functions. Ivarmacitinib is a highly selective JAK1 inhibitor. JAK1 regulates various cytokines such as IL-4, IL-5, IL-13, and IFN-γ, while Ivarmacitinib does not inhibit JAK2, thereby reducing the risk of adverse reactions such as anemia and neutropenia. By inhibiting this pathway, Ivarmacitinib may help prevent immune dysregulation that leads to various inflammatory diseases, including atopic dermatitis and rheumatic diseases such as rheumatoid arthritis.
SHR-0302 (Ivarmacitinib) is a potent and orally active selective JAK1 inhibitor with >10-fold selectivity over JAK2, 77-fold over JAK3, and 420-fold over Tyk2. It inhibits JAK1-STAT3 phosphorylation and induces apoptosis of hepatic stellate cells, with anti-proliferative and anti-inflammatory effects. The compound is used in research on fibrosis, inflammation, and autoimmune diseases. Under clinical development for inflammatory conditions.

C18H22N8O2S

414.4847

414.16

C, 52.16; H, 5.35; N, 27.03; O, 7.72; S, 7.73

1445987-21-2

1445987-21-2;1639419-51-4 (sulfate);1639419-53-6 (HCl);

71622431

Off-white to light yellow solid powder

2.3

2

8

4

29

600

2

CN(C1C[C@@H]2CN(C[C@@H]2C1)C(=O)NC3=NC(=NS3)OC)C4=NC=NC5=C4C=CN5

DNBCBAXDWNDRNO-FOSCPWQOSA-N

InChI=1S/C18H22N8O2S/c1-25(15-13-3-4-19-14(13)20-9-21-15)12-5-10-7-26(8-11(10)6-12)18(27)23-17-22-16(28-2)24-29-17/h3-4,9-12H,5-8H2,1-2H3,(H,19,20,21)(H,22,23,24,27)/t10-,11+,12?

(3aS,6aR)-N-(3-methoxy-1,2,4-thiadiazol-5-yl)-5-[methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino]-3,3a,4,5,6,6a-hexahydro-1H-cyclopenta[c]pyrrole-2-carboxamide

SHR0302 SHR-0302 SHR 0302

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~31.25 mg/mL (~75.40 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (5.02 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.08 mg/mL (5.02 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.08 mg/mL (5.02 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)