Cat. No.: HY-100754

Ritlecitinib

(Synonyms: PF-06651600)

9 Cited Publications

Customer Review

Based on 9 publication(s) in Google Scholar

Ritlecitinib (PF-06651600) is a highly selective, orally active, irreversible covalent JAK3 inhibitor (IC₅₀=33 nM) without inhibitory activity towards JAK1, JAK2, and TYK2 (IC₅₀ >10 μ M). Ritlecitinib rapidly inactivates the JAK3 kinase, and blocks signaling and downstream STAT phosphorylation mediated by common gamma chain cytokines such as IL-2 and IL-15. Ritlecitinib can inhibit Th1/Th17 cell differentiation and function, and effectively suppress preclinical animal models such as alopecia areata, adjuvant-induced arthritis (AIA), and experimental autoimmune encephalomyelitis (EAE).

For research use only. We do not sell to patients.

Purity: 99.63%
CAS No.: 1792180-81-4
Formula: C₁₅H₁₉N₅O
Molecular Weight:285.35

Storage:

Powder -20°C, 3 years , 4°C, 2 years ; In solvent -80°C, 2 years , -20°C, 1 year

Ritlecitinib Chemical Structure

CAS No.: 1792180-81-4

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Top Publications Citing

Use of MCE Products

Fluorescent Dye

Strong Fluorescence Signal / Multi-Disciplinary Applications / High Fluorescence Specificity

Biological Activity
- Description
- IC₅₀ & Target
- Cellular Effect
- In Vitro
- In Vivo
- Clinical Trial
Chemical Information
Publications (9)
Solvent & Solubility
- In Vitro
- In Vivo
Purity & Documentation
References
Help & FAQs
Classifications
Bioz

Biological Activity

Description

IC₅₀ & Target^[1]

JAK3

33.1 nM (IC₅₀)

IL-4

IL7R

IL-15

STAT3

STAT5

STAT6

All JAK Isoforms :

All Interleukin Related Isoforms :

All STAT Isoforms :

Cellular Effect

Cell Line	Type	Value	Description	References
BaF3	IC₅₀	>10000 nM Compound: 11; PF-06651600	Antiproliferative activity against mouse BaF3 cells harboring TEL-JAK2 fusion protein assessed as inhibition of cell growth measured after 72 hrs by CCK-8 assay Antiproliferative activity against mouse BaF3 cells harboring TEL-JAK2 fusion protein assessed as inhibition of cell growth measured after 72 hrs by CCK-8 assay	[PMID: 35860875]
BaF3	IC₅₀	>10000 nM Compound: 11; PF-06651600	Antiproliferative activity against mouse BaF3 parent cell measured after 72 hrs by CCK-8 assay Antiproliferative activity against mouse BaF3 parent cell measured after 72 hrs by CCK-8 assay	[PMID: 35860875]
BaF3	IC₅₀	28.1 nM Compound: 11; PF-06651600	Antiproliferative activity against mouse BaF3 cells harboring JAK3 M5111 mutant assessed as inhibition of cell growth measured after 72 hrs by CCK-8 assay Antiproliferative activity against mouse BaF3 cells harboring JAK3 M5111 mutant assessed as inhibition of cell growth measured after 72 hrs by CCK-8 assay	[PMID: 35860875]
BaF3	IC₅₀	>10000 nM Compound: 11; PF-06651600	Antiproliferative activity against mouse BaF3 cells harboring TEL-JAK1 fusion protein assessed as inhibition of cell growth measured after 72 hrs by CCK-8 assay Antiproliferative activity against mouse BaF3 cells harboring TEL-JAK1 fusion protein assessed as inhibition of cell growth measured after 72 hrs by CCK-8 assay	[PMID: 35860875]
CD4+ve Th	IC₅₀	48 nM Compound: PF-06651600	Inhibition of Th1 cell differentiation in human peripheral blood CD4+ve Th cells assessed as decrease in IFNgamma production measured after 5 days Inhibition of Th1 cell differentiation in human peripheral blood CD4+ve Th cells assessed as decrease in IFNgamma production measured after 5 days	[PMID: 36561076]
U-937	IC₅₀	0.04 μM Compound: 5; PF-06651600	Antiproliferative activity against human U-937 cells harbouring JAK3 M511 mutation assessed as reduction in cell viability incubated for 72 hrs by CCK-8 assay Antiproliferative activity against human U-937 cells harbouring JAK3 M511 mutation assessed as reduction in cell viability incubated for 72 hrs by CCK-8 assay	[PMID: 35306167]
U-937	IC₅₀	19.5 nM Compound: 11; PF-06651600	Antiproliferative activity against human U-937 cells harboring JAK3 M511135 mutant assessed as inhibition of cell growth measured after 72 hrs by CCK-8 assay Antiproliferative activity against human U-937 cells harboring JAK3 M511135 mutant assessed as inhibition of cell growth measured after 72 hrs by CCK-8 assay	[PMID: 35860875]

In Vitro

Ritlecitinib inhibits IL-15 in peripheral blood mononuclear cells (PBMCs) and heparin treated human whole blood (HWB) with IC₅₀ of 51 nM and 197 nM, respectively^[1].
Ritlecitinib inhibits the phosphorylation of STAT proteins mediated by IL-2 (STAT5), IL-4 (STAT6), IL-7 (STAT5), IL-15 (STAT5), and IL-21 (STAT3) at concentrations of 244 nM, 340 nM, 407 nM, 266 nM, and 355 nM (IC₅₀), respectively^[2].
Ritlecitinib (30 nM, 167 nM; 5 days, 6 days) inhibits cell differentiation in Th1 and Th17 cell differentiation inhibition experiments for 5 days under Th1 conditions and 6 days under Th17 conditions, respectively^[2].

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

Western Blot Analysis^[1]

Cell Line:

Mouse splenocytes, human whole blood lymphocytes (HWB)
Concentration:

33.1 nM, 244 nM, 340 nM, 407 nM, 266 nM, 355 nM
Incubation Time:

1 hour (pre-treatment with Ritlecitinib) + 15-20 minutes (cytokine stimulation)
Result:

In mouse splenocytes, 33.1 nM inhibited JAK3 kinase activity, while 244 nM, 340 nM, 407 nM, and 266 nM inhibited STAT5 phosphorylation induced by IL-2, IL-4, IL-7, and IL-15 respectively. In human whole blood lymphocytes, 355 nM inhibited IL-21-induced STAT3 phosphorylation.

In Vivo

Ritlecitinib (3, 10, 30 mg/kg; oral; once daily; 7 days) reduces joint swelling and improves disease severity in a dose-dependent manner in the Sprague-Dawley rat adjuvant-induced arthritis (AIA) model^[2].
Ritlecitinib (30, 100 mg/kg (reversal); 20, 60 mg/kg (prevention); oral; once daily) reduces disease severity in the mouse experimental autoimmune encephalomyelitis (EAE) model^[2].
Ritlecitinib (30 mg/kg; oral; once daily; 4 weeks) can prevent the occurrence of alopecia areata in the C3H/HeJ mouse skin transplantation alopecia areata prevention model; Ritlecitinib (30 mg/kg; oral; once daily; 12 weeks) can reverse the symptoms of alopecia areata, promote hair regeneration and reduce skin inflammation in the C3H/HeJ mouse alopecia areata model^[3].

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

Animal Model:

C3H/HeJ mice (8-week-old) + alopecia areata model^[3]
Dosage:

30 mg/kg
Administration:

Oral via ALZET osmotic pump; once daily; 12 weeks
Result:

Significantly induced hair regrowth, reduced skin-infiltrating CD45⁺ leukocytes, CD44⁺CD62L⁻CD8⁺ T cells, NKG2D⁺CD8⁺ T cells, and IFN-γ⁺CD8⁺ T cells, and decreased Alopecia areata (AA)-associated skin inflammation.

Clinical Trial

NCT Number	Sponsor	Condition	Start Date	Phase A549
NCT01329991	Plexxikon\|		2011-05	PHASE1

Chemical Information

CAS No. 1792180-81-4
Appearance Solid
Molecular Weight 285.35
Formula C₁₅H₁₉N₅O
Color White to yellow
SMILES

C=CC(N1[C@@H](C)CC[C@@H](NC2=C3C(NC=C3)=NC=N2)C1)=O
Synonyms

PF-06651600
Shipping

Room temperature in continental US; may vary elsewhere.

Storage

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	2 years
	-20°C	1 year

Publications (9)

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Journal Impact Factor

Ann Rheum Dis

Augmentation of immunothrombosis as a key mechanism underlying JAK inhibition associated hypercoagulability in rheumatoid arthritis. [Abstract]

2025 Sep 25:S0003-4967(25)04383-3. PMID: 41006174
Blood Adv

Latent membrane proteins from EBV differentially target cellular pathways to accelerate MYC-induced lymphomagenesis. [Abstract]

2022 Jul 26;6(14):4283-4296. PMID: 35605249
Int J Mol Sci

Epstein-Barr Virus BRRF1 Induces Butyrophilin 2A1 in Nasopharyngeal Carcinoma NPC43 Cells via the IL-22/JAK3-STAT3 Pathway. [Abstract]

2024 Dec 15;25(24):13452. PMID: 39769218

Ritlecitinib purchased from MedChemExpress. Usage Cited in: Int J Mol Sci. 2024 Dec 15;25(24):13452. [Abstract]

Ritlecitinib (0.5-5 μM) significantly decreased the gene expression level of BTN2A1 in NPC43 cells.

Ritlecitinib purchased from MedChemExpress. Usage Cited in: Int J Mol Sci. 2024 Dec 15;25(24):13452. [Abstract]

STAT3, p-STAT3, STAT1, p-STAT1, STAT5, p-STAT5, JNK, and p-JNK protein expression of NPC43 cells by BRRF1 overexpression with or without Ritlecitinib (5 μM) treatment. Representative immunoblots are shown.
Int J Mol Sci

JAK Signaling Is Critically Important in Cytokine-Induced Viral Susceptibility of Keratinocytes. [Abstract]

2023 May 25;24(11):9243. PMID: 37298195
Expert Opin Investig Drugs

Ritlecitinib: an investigational drug for the treatment of moderate to severe alopecia areata. [Abstract]

2021 Dec;30(12):1169-1174. PMID: 34826225
Clin Immunol

Novel janus kinase 3 inhibitor ritlecitinib suppresses T and B cell responses to prevent acute cardiac allograft rejection in mice. [Abstract]

2025 Feb 13:273:110445. PMID: 39954912
Res Sq

2026 Apr 13.
bioRxiv

2026 Mar 7.
bioRxiv

2023 Aug 17.

Solvent & Solubility

In Vitro:

DMSO : 100 mg/mL (350.45 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

View the Complete Stock Solution Preparation Table

Preparing Stock Solutions

View the Complete Stock Solution Preparation Table

Concentration Solvent Mass

1 mg

5 mg

10 mg

Concentration

Solvent

Mass

1 mM

3.5045 mL

17.5223 mL

35.0447 mL

5 mM

0.7009 mL

3.5045 mL

7.0089 mL

10 mM

0.3504 mL

1.7522 mL

3.5045 mL

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, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

Molarity Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

Mass Mass

Concentration Concentration

Volume Volume

Molecular Weight Molecular Weight

Dilution Calculator

Concentration _(start) × Volume _(start) = Concentration _(final) × Volume _(final)

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In Vivo:

Select the appropriate dissolution method based on your experimental animal and administration route.

Stock Solution Working Solution

For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for In Vivo experiments, it is recommended to prepare freshly and use it on the same day.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 10% DMSO 40% PEG300 5% Tween-80 45% Saline

Solubility: ≥ 2.08 mg/mL (7.29 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.

Protocol 2

Add each solvent one by one: 10% DMSO 90% (20% SBE-β-CD in Saline)

Solubility: ≥ 2.08 mg/mL (7.29 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.

Protocol 3

Add each solvent one by one: 10% DMSO 90% Corn Oil

Solubility: ≥ 2.08 mg/mL (7.29 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown). If the continuous dosing period exceeds half a month, please choose this protocol carefully.

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL Corn oil, and mix evenly.

Working Solution

For the following dissolution methods, please prepare the working solution directly:

It is recommended to prepare fresh solutions and use them promptly within a short period of time.

The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 0.5% Methyl cellulose/0.5% Tween-80 in Saline water

Solubility: 6.67 mg/mL (23.37 mM); Suspended solution; Need ultrasonic

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage Dosage
mg/kg
Animal Weight (Per Animal) Animal Weight (Per Animal)
g
Dosing Volume (Per Animal) Dosing Volume (Per Animal)
μL
Number of Animals Number of Animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Please enter your animal formula composition:

%
DMSO +

Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
%
+
+
%
Tween-80 + +
%
Saline +

The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).

Working solution concentration: 0.22 mg/mL

Purity & Documentation

Select Batch:

Purity: 99.98%

Assay: 99.98%

ee.: 99.98%

Data Sheet (282 KB)
SDS (396 KB)
- English - EN (396 KB)
- Français - FR (396 KB)
- Deutsch - DE (396 KB)
- Norwegian - NO (396 KB)
- Español - ES (396 KB)
- Swedish - SV (396 KB)
- Italian - IT (396 KB)
- Korean - KR (396 KB)
- Portuguese - PT (396 KB)
COA (2659 KB)
Elemental Analysis Report (2659 KB)
HNMR (2659 KB)
CNMR (2659 KB)
RP-HPLC (2659 KB)
NP-HPLC (2659 KB)
MS (2659 KB)
LCMS (2659 KB)
IR (2659 KB)
GC (2659 KB)
OR (2659 KB)
SDS-PAGE (2659 KB)
SEC-HPLC (2659 KB)
Other Report (2659 KB)
Handling Instructions (2659 KB)

References

[1]. Thorarensen A, et al. Design of a Janus Kinase 3 (JAK3) Specific Inhibitor 1-((2 S, 5 R)-5-((7 H-Pyrrolo [2, 3-d] pyrimidin-4-yl) amino)-2-methylpiperidin-1-yl) prop-2-en-1-one (PF-06651600) Allowing for the Interrogation of JAK3 Signaling in Humans. Journal of medicinal chemistry, 2017, 60(5): 1971-1993.

[2]. Telliez JB, et al. Discovery of a JAK3-Selective Inhibitor: Functional Differentiation of JAK3-Selective Inhibition over pan-JAK or JAK1-Selective Inhibition. ACS Chem Biol. 2016 Dec 16;11(12):3442-3451. [Content Brief]

Help & FAQs

How should lyophilized recombinant proteins be reconstituted and stored?

1. Before opening the cap, centrifuge the vial at 13000 rpm for 20-30 seconds. This step will ensure that any lyophilized powder that may have adhered to the cap or walls is collected at the bottom of the vial, minimizing the risk of product loss.

Complete Stock Solution Preparation Table

Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg
DMSO	1 mM	3.5045 mL	17.5223 mL	35.0447 mL	87.6117 mL
	5 mM	0.7009 mL	3.5045 mL	7.0089 mL	17.5223 mL
	10 mM	0.3504 mL	1.7522 mL	3.5045 mL	8.7612 mL
	15 mM	0.2336 mL	1.1682 mL	2.3363 mL	5.8408 mL
	20 mM	0.1752 mL	0.8761 mL	1.7522 mL	4.3806 mL
	25 mM	0.1402 mL	0.7009 mL	1.4018 mL	3.5045 mL
	30 mM	0.1168 mL	0.5841 mL	1.1682 mL	2.9204 mL
	40 mM	0.0876 mL	0.4381 mL	0.8761 mL	2.1903 mL
	50 mM	0.0701 mL	0.3504 mL	0.7009 mL	1.7522 mL
	60 mM	0.0584 mL	0.2920 mL	0.5841 mL	1.4602 mL
	80 mM	0.0438 mL	0.2190 mL	0.4381 mL	1.0951 mL
	100 mM	0.0350 mL	0.1752 mL	0.3504 mL	0.8761 mL

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Ritlecitinib

Epigenetics Compound Library

Immunology/Inflammation Compound Library

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Publications Citing Use of MedChemExpress (MCE) Ritlecitinib

All JAK Isoforms

All Interleukin Related Isoforms

All STAT Isoforms

Biological Activity

Chemical Information

Publications (9)

Solvent & Solubility

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

Ritlecitinib Related Classifications

HY-100754 Related Classifications