Syk inhibitors

Syk, a non-receptor protein tyrosine kinase, is a key mediator of immune receptor signaling and platelets. Syk, with Src homology 2 (SH2) domains, plays essential roles in signalling activated by various types of receptors such as FccR, CR3, Dectin-1 and apoptotic cell-recognizing receptor. Syk also plays an important part in the uncontrolled growth of tumor cells. The tandem SH2-domain-containing Syk is activated when classical ITAMs is tyrosine-phosphorylated by SRC kinases. The downstream of syk includes Ras, Raf and MAPK signaling pathway.

Angiogenesis

DPP Aminopeptidase Procollagen C Proteinase P450 (e.g. CYP17) Phospholipase (e.g. PLA) Factor Xa PDE DHFR Carbonic Anhydrase Hydroxylase Liver X Receptor FAAH Acyltransferase Dehydrogenase Phosphorylase PPAR CYP17 CETP FXR HMG-CoA Reductase Transferase IDO/TDO Retinoid Receptor Casein Kinase NAMPT phosphatase Lipase Lipoxygenase Thioredoxin Decarboxylase Vitamin Serine/threonin kinase LDL Fatty Acid Synthase FOX Glycogen synthesis PKM Glycolysis HDL Carbohydrate Metabolism ATP-citrate lyase Acetyl-CoA carboxylase CYP450 PCSK9 Leukotriene PDHK PGC-1α ROR FABP Peroxidases Aldose Reductase Xanthine Oxidase THR Epoxide Hydrolase PEP GTPCH FAO PAI-1 LDH SCD CPSase Mannosidase Thioredoxin Reductase SGK FTase γGCS CPT SREBP Mitochondrial Metabolism PARG Glucosylceramide Synthase Catalase 3-MST Serine hydrolase CAR glucocerebrosidase Mitochondrial pyruvate carrier GOT SHIP SOD LCN Endogenous Metabolite ATGL NMT Aconitase AGEs Amino Acids and Derivatives Amylase Drug Metabolite Glucokinase Glucosidase glycosidase GSNOR GST Hexokinase Isocitrate Dehydrogenase (IDH) Lipid Liposome LPL Receptor MAGL NEDD4-1 NPC1L1 PGK1 Reductase stilbene oxidase UGT

Isoform-selective Products

ZAP70

All (24)
Syk Inhibitors (24)
New Syk Products

Cat.No.	Product Name	Information	Product Use Citations
S2194	R406	R406(R406 besylate) is a potent Syk inhibitor with IC50 of 41 nM in cell-free assays, strongly inhibits Syk but not Lyn, 5-fold less potent to Flt3. R406 induces apoptosis. Phase 1.	J Allergy Clin Immunol, 2025, 155(2):569-582 Int J Biol Sci, 2025, 21(12):5287-5304 Front Immunol, 2025, 16:1636917
S1533	R406 (free base)	R406 (free base) is a potent Syk inhibitor with IC50 of 41 nM in a cell-free assay, strongly inhibits Syk but not Lyn, 5-fold less potent to Flt3. This compound triggers apoptosis. Phase 1.	Autophagy, 2025, 1-17. EMBO Rep, 2025, 10.1038/s44319-025-00444-2 J Transl Med, 2024, 22(1):283
S8032	PRT062607 (P505-15) HCl	PRT062607 (P505-15, BIIB057, PRT-2607) HCl is a novel, highly selective Syk inhibitor with IC50 of 1 nM in cell-free assays, >80-fold selective for Syk than Fgr, PAK5, Lyn, FAK, Pyk2, FLT3, MLK1 and Zap70.	Sci Adv, 2025, 11(31):eadu4270 Sci Rep, 2024, 14(1):7739 J Exp Med, 2023, 220(9)e20230054
S7523	Entospletinib (GS-9973)	Entospletinib (GS-9973) is an orally bioavailable, selective Syk inhibitor with IC50 of 7.7 nM in a cell-free assay. This compound showed 13- to >1000-fold cellular selectivity for Syk over other kinases (including Jak2, ckit, Flt3, Ret, KDR) as assessed by target protein phosphorylation or functional response.	Cancer Res, 2023, 83(2):316-331 Front Immunol, 2023, 14:1279155 J Leukoc Biol, 2023, qiad025
S2625	Fostamatinib (R788)	Fostamatinib (R788), a prodrug of the active metabolite R406, is a Syk inhibitor with IC50 of 41 nM. It strongly inhibits Syk but not Lyn, and is 5-fold less potent to Flt3. Phase 3.	Autophagy, 2025, 1-17. Int Immunopharmacol, 2025, 148:114122 Exp Ther Med, 2025, 29(6):110
S3026	Piceatannol	Piceatannol, a natural stilbene, is a selective Syk inhibitor and ~10-fold selectivity versus Lyn.	Autophagy, 2025, 1-17. Int J Mol Sci, 2025, 26(18)9134 ACS Appl Mater Interfaces, 2022, 14(21):24144-24159
S2206	Fostamatinib (R788) disodium	Fostamatinib disodium (R788, Tamatinib Fosdium), a prodrug of the active metabolite R406, is a Syk inhibitor with IC50 of 41 nM in a cell-free assay, strongly inhibits Syk but not Lyn, 5-fold less potent to Flt3. Phase 3.	Autophagy, 2025, 1-17. Sci Rep, 2025, 15(1):25312 FASEB J, 2024, 38(6):e23564
S7006	BAY 61-3606 dihydrochloride	BAY 61-3606 dihydrochloride is a potent and selective inhibitor of Syk kinase (Ki = 7.5 nM). BAY-61-3606 induces cell cycle arrest and apoptosis.	EMBO Rep, 2025, 10.1038/s44319-025-00444-2 bioRxiv, 2025, 2025.05.30.657101 Arterioscler Thromb Vasc Biol, 2024, 44(7):1646-1657
S7738	PRT-060318 2HCl	PRT-060318 (PRT318) is a novel selective inhibitor of the Syk tyrosine kinase with an IC50 of 4 nM, as an approach to HIT treatment.	Microbiol Spectr, 2025, 13(1):e0254921 Cell Mol Life Sci, 2024, 82(1):14 PLoS Pathog, 2024, 20(10):e1012674
S8442	TAK-659 Hydrochloride	TAK-659 Hydrochloride is a potent and selective inhibitor of spleen tyrosine kinase (SYK) with an IC50 value of 3.2 nM. It is selective against most other kinases, but potent toward both SYK and FLT3.	Exp Ther Med, 2025, 29(6):110 Int J Mol Sci, 2024, 25(18)9914 Int J Mol Sci, 2022, 23(23)14706
S4944	Fostamatinib disodium hexahydrate	Fostamatinib (R788) disodium (Tamatinib Fosdium) hexahydrate, a prodrug of the active metabolite R406, is a Syk inhibitor with IC50 of 41 nM in a cell-free assay.	Int J Hematol, 2022, 10.1007/s12185-021-03220-9 J Allergy Clin Immunol, 2021, S0091-6749(21)00979-9 ScholarsArchive@OSU, 2020, None
S7286	RO9021	RO9021 potently inhibits SYK kinase activity with an average IC50 of 5.6 nM and suppresses B-cell receptor signaling.	Microbiol Spectr, 2025, 13(1):e0254921 Int J Mol Sci, 2022, 23(23)14706
S6519	R112	R112 is an ATP-competitive spleen tyrosine kinase (Syk) inhibitor with Ki value of 96 nM.
E1836	Cevidoplenib dimesylate	Cevidoplenib dimesylate(SKI-O-703 dimesylate) is an orally available inhibitor of spleen tyrosine kinase (Syk) with potential anti-inflammatory and immunomodulating activities. It attenuates the progression of autoantibody-mediated autoimmune diseases by inhibiting both autoantibody-producing and autoantibody-sensing cells.
S0871	Gusacitinib (ASN-002)	Gusacitinib (ASN-002) is a novel and potent dual inhibitor of spleen tyrosine kinase (SYK) and Janus kinases (JAK) with IC50 values of 5-46 nM in biochemical assays.
S9715	Lanraplenib (GS-SYK)	Lanraplenib (GS-SYK) is a potent, highly selective and orally active inhibitor of Spleen Tyrosine Kinase (SYK) with IC50 of 9.5 nM. It inhibits SYK activity in platelets via the glycoprotein VI (GPVI) receptor without prolonging bleeding time (BT) in monkeys or humans.	Cell Rep, 2024, 43(10):114773 Blood Adv, 2024, bloodadvances.2024014167 bioRxiv, 2024, 2024.09.26.615160
S8948	SRX3207	SRX3207 is an orally active dual inhibitor of Syk-PI3K with IC50 of 39.9 nM, 31200 nM, 3070 nM, 3070 nM, 244 nM, 388 nM, 9790 nM for Syk, Zap70, BRD41, BRD42, PI3K alpha, PI3K delta, PI3K gamma, respectively. This compound blocks tumor immunosuppression and increases anti-tumor immunity.
E0437	ZAP-180013	ZAP-180013 is a inhibitor of zeta-chain-associated protein kinase 70 (ZAP-70) with an IC50 of 1.8 μM.
E7793	PRT062607	PRT062607 is a highly specific, potent and orally bioavailable inhibitor of purified Spleen tyrosine kinase (SYK) with an IC50 of 1-2 nM. It exhibits significant anti-inflammatory activity and can be used in non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL) and rheumatoid arthritis research.
E4580	Sovleplenib	Sovleplenib (HMPL-523) is a highly potent and selective SYK inhibitor with IC50 of 0.025 μM, that exhibits anti-tumor activities in vitro and in vivo. This compound exhibits synergistic activities in combination with BTK, PI3Kδ, and Bcl2 family inhibitors in killing human-diffused large B cell lymphoma (DLBCL).
S7634	Cerdulatinib (PRT062070) hydrochloride	Cerdulatinib (PRT-062070, PRT2070) hydrochloride is an oral active, multi-targeted tyrosine kinase inhibitor with IC50 of 12 nM/6 nM/8 nM/0.5 nM and 32 nM for JAK1/JAK2/JAK3/TYK2 and Syk, respectively. Also inhibits 19 other tested kinases with IC50 less than 200 nM.	Antimicrob Agents Chemother, 2024, 68(4):e0135023. Int J Mol Sci, 2023, 24(17)13623 Cells, 2023, 12(3)453
S3566	Cerdulatinib (PRT062070)	Cerdulatinib (PRT062070, PRT2070) is an oral active, multi-targeted tyrosine kinase inhibitor with IC50 of 12 nM/6 nM/8 nM/0.5 nM and 32 nM for JAK1/JAK2/JAK3/TYK2 and Syk, respectively, also inhibits19 other tested kinases with IC50 less than 200 nM.	Cell Rep Med, 2025, S2666-3791(25)00102-8 Methods, 2025, 241:13-23 NPJ Precis Oncol, 2024, 8(1):74
S4921	MNS (3,4-Methylenedioxy-β-nitrostyrene)	MNS (3,4-Methylenedioxy-β-nitrostyrene) is a tyrosine kinase inhibitor that inhibits Syk, Src, and p97 with IC50 values of 2.5 μM, 29.3 μM, and 1.7 μM, respectively.	Journal of Biomedical Engineering, 2021, 38(5):903-910 Phytomedicine, 2019, 61:152859 J Biomol Struct Dyn, 2019, 10.1080/07391102.2019.1640133
S3226	Dehydroabietic acid	Dehydroabietic acid (DAA, DHAA), a naturally occurring diterpene resin acid derived from coniferous plants such as Pinus and Picea, displays anti-inflammatory activity via suppression of Src-, Syk-, and TAK1-mediated pathways.
S2194	R406	R406(R406 besylate) is a potent Syk inhibitor with IC50 of 41 nM in cell-free assays, strongly inhibits Syk but not Lyn, 5-fold less potent to Flt3. R406 induces apoptosis. Phase 1.	J Allergy Clin Immunol, 2025, 155(2):569-582 Int J Biol Sci, 2025, 21(12):5287-5304 Front Immunol, 2025, 16:1636917
S1533	R406 (free base)	R406 (free base) is a potent Syk inhibitor with IC50 of 41 nM in a cell-free assay, strongly inhibits Syk but not Lyn, 5-fold less potent to Flt3. This compound triggers apoptosis. Phase 1.	Autophagy, 2025, 1-17. EMBO Rep, 2025, 10.1038/s44319-025-00444-2 J Transl Med, 2024, 22(1):283
S8032	PRT062607 (P505-15) HCl	PRT062607 (P505-15, BIIB057, PRT-2607) HCl is a novel, highly selective Syk inhibitor with IC50 of 1 nM in cell-free assays, >80-fold selective for Syk than Fgr, PAK5, Lyn, FAK, Pyk2, FLT3, MLK1 and Zap70.	Sci Adv, 2025, 11(31):eadu4270 Sci Rep, 2024, 14(1):7739 J Exp Med, 2023, 220(9)e20230054
S7523	Entospletinib (GS-9973)	Entospletinib (GS-9973) is an orally bioavailable, selective Syk inhibitor with IC50 of 7.7 nM in a cell-free assay. This compound showed 13- to >1000-fold cellular selectivity for Syk over other kinases (including Jak2, ckit, Flt3, Ret, KDR) as assessed by target protein phosphorylation or functional response.	Cancer Res, 2023, 83(2):316-331 Front Immunol, 2023, 14:1279155 J Leukoc Biol, 2023, qiad025
S2625	Fostamatinib (R788)	Fostamatinib (R788), a prodrug of the active metabolite R406, is a Syk inhibitor with IC50 of 41 nM. It strongly inhibits Syk but not Lyn, and is 5-fold less potent to Flt3. Phase 3.	Autophagy, 2025, 1-17. Int Immunopharmacol, 2025, 148:114122 Exp Ther Med, 2025, 29(6):110
S3026	Piceatannol	Piceatannol, a natural stilbene, is a selective Syk inhibitor and ~10-fold selectivity versus Lyn.	Autophagy, 2025, 1-17. Int J Mol Sci, 2025, 26(18)9134 ACS Appl Mater Interfaces, 2022, 14(21):24144-24159
S2206	Fostamatinib (R788) disodium	Fostamatinib disodium (R788, Tamatinib Fosdium), a prodrug of the active metabolite R406, is a Syk inhibitor with IC50 of 41 nM in a cell-free assay, strongly inhibits Syk but not Lyn, 5-fold less potent to Flt3. Phase 3.	Autophagy, 2025, 1-17. Sci Rep, 2025, 15(1):25312 FASEB J, 2024, 38(6):e23564
S7006	BAY 61-3606 dihydrochloride	BAY 61-3606 dihydrochloride is a potent and selective inhibitor of Syk kinase (Ki = 7.5 nM). BAY-61-3606 induces cell cycle arrest and apoptosis.	EMBO Rep, 2025, 10.1038/s44319-025-00444-2 bioRxiv, 2025, 2025.05.30.657101 Arterioscler Thromb Vasc Biol, 2024, 44(7):1646-1657
S7738	PRT-060318 2HCl	PRT-060318 (PRT318) is a novel selective inhibitor of the Syk tyrosine kinase with an IC50 of 4 nM, as an approach to HIT treatment.	Microbiol Spectr, 2025, 13(1):e0254921 Cell Mol Life Sci, 2024, 82(1):14 PLoS Pathog, 2024, 20(10):e1012674
S8442	TAK-659 Hydrochloride	TAK-659 Hydrochloride is a potent and selective inhibitor of spleen tyrosine kinase (SYK) with an IC50 value of 3.2 nM. It is selective against most other kinases, but potent toward both SYK and FLT3.	Exp Ther Med, 2025, 29(6):110 Int J Mol Sci, 2024, 25(18)9914 Int J Mol Sci, 2022, 23(23)14706
S4944	Fostamatinib disodium hexahydrate	Fostamatinib (R788) disodium (Tamatinib Fosdium) hexahydrate, a prodrug of the active metabolite R406, is a Syk inhibitor with IC50 of 41 nM in a cell-free assay.	Int J Hematol, 2022, 10.1007/s12185-021-03220-9 J Allergy Clin Immunol, 2021, S0091-6749(21)00979-9 ScholarsArchive@OSU, 2020, None
S7286	RO9021	RO9021 potently inhibits SYK kinase activity with an average IC50 of 5.6 nM and suppresses B-cell receptor signaling.	Microbiol Spectr, 2025, 13(1):e0254921 Int J Mol Sci, 2022, 23(23)14706
S6519	R112	R112 is an ATP-competitive spleen tyrosine kinase (Syk) inhibitor with Ki value of 96 nM.
E1836	Cevidoplenib dimesylate	Cevidoplenib dimesylate(SKI-O-703 dimesylate) is an orally available inhibitor of spleen tyrosine kinase (Syk) with potential anti-inflammatory and immunomodulating activities. It attenuates the progression of autoantibody-mediated autoimmune diseases by inhibiting both autoantibody-producing and autoantibody-sensing cells.
S0871	Gusacitinib (ASN-002)	Gusacitinib (ASN-002) is a novel and potent dual inhibitor of spleen tyrosine kinase (SYK) and Janus kinases (JAK) with IC50 values of 5-46 nM in biochemical assays.
S9715	Lanraplenib (GS-SYK)	Lanraplenib (GS-SYK) is a potent, highly selective and orally active inhibitor of Spleen Tyrosine Kinase (SYK) with IC50 of 9.5 nM. It inhibits SYK activity in platelets via the glycoprotein VI (GPVI) receptor without prolonging bleeding time (BT) in monkeys or humans.	Cell Rep, 2024, 43(10):114773 Blood Adv, 2024, bloodadvances.2024014167 bioRxiv, 2024, 2024.09.26.615160
S8948	SRX3207	SRX3207 is an orally active dual inhibitor of Syk-PI3K with IC50 of 39.9 nM, 31200 nM, 3070 nM, 3070 nM, 244 nM, 388 nM, 9790 nM for Syk, Zap70, BRD41, BRD42, PI3K alpha, PI3K delta, PI3K gamma, respectively. This compound blocks tumor immunosuppression and increases anti-tumor immunity.
E0437	ZAP-180013	ZAP-180013 is a inhibitor of zeta-chain-associated protein kinase 70 (ZAP-70) with an IC50 of 1.8 μM.
E7793	PRT062607	PRT062607 is a highly specific, potent and orally bioavailable inhibitor of purified Spleen tyrosine kinase (SYK) with an IC50 of 1-2 nM. It exhibits significant anti-inflammatory activity and can be used in non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL) and rheumatoid arthritis research.
E4580	Sovleplenib	Sovleplenib (HMPL-523) is a highly potent and selective SYK inhibitor with IC50 of 0.025 μM, that exhibits anti-tumor activities in vitro and in vivo. This compound exhibits synergistic activities in combination with BTK, PI3Kδ, and Bcl2 family inhibitors in killing human-diffused large B cell lymphoma (DLBCL).
S7634	Cerdulatinib (PRT062070) hydrochloride	Cerdulatinib (PRT-062070, PRT2070) hydrochloride is an oral active, multi-targeted tyrosine kinase inhibitor with IC50 of 12 nM/6 nM/8 nM/0.5 nM and 32 nM for JAK1/JAK2/JAK3/TYK2 and Syk, respectively. Also inhibits 19 other tested kinases with IC50 less than 200 nM.	Antimicrob Agents Chemother, 2024, 68(4):e0135023. Int J Mol Sci, 2023, 24(17)13623 Cells, 2023, 12(3)453
S3566	Cerdulatinib (PRT062070)	Cerdulatinib (PRT062070, PRT2070) is an oral active, multi-targeted tyrosine kinase inhibitor with IC50 of 12 nM/6 nM/8 nM/0.5 nM and 32 nM for JAK1/JAK2/JAK3/TYK2 and Syk, respectively, also inhibits19 other tested kinases with IC50 less than 200 nM.	Cell Rep Med, 2025, S2666-3791(25)00102-8 Methods, 2025, 241:13-23 NPJ Precis Oncol, 2024, 8(1):74
S4921	MNS (3,4-Methylenedioxy-β-nitrostyrene)	MNS (3,4-Methylenedioxy-β-nitrostyrene) is a tyrosine kinase inhibitor that inhibits Syk, Src, and p97 with IC50 values of 2.5 μM, 29.3 μM, and 1.7 μM, respectively.	Journal of Biomedical Engineering, 2021, 38(5):903-910 Phytomedicine, 2019, 61:152859 J Biomol Struct Dyn, 2019, 10.1080/07391102.2019.1640133
S3226	Dehydroabietic acid	Dehydroabietic acid (DAA, DHAA), a naturally occurring diterpene resin acid derived from coniferous plants such as Pinus and Picea, displays anti-inflammatory activity via suppression of Src-, Syk-, and TAK1-mediated pathways.

Syk inhibitors

Angiogenesis

Isoform-selective Products

Signaling Pathway Map