Pacritinib (SB1518) citrate is a potent inhibitor of wild-type JAK2 and JAK2V617F mutant with IC50 of 23 nM and 19 nM, respectively. Pacritinib citrate also inhibits FLT3 and its mutant FLT3D835Y with IC50 of 22 nM and 6 nM, respectively. Pacritinib citrate can be used in the research of acute myeloid leukemia (AML) and myelofibrosis (MF).

Physicochemical Properties

Molecular Formula	C34H40N4O10
Molecular Weight	664.70
Exact Mass	664.274
CAS #	1228923-42-9
PubChem CID	46216795
Appearance	Typically exists as solid at room temperature
Hydrogen Bond Donor Count	5
Hydrogen Bond Acceptor Count	14
Rotatable Bond Count	9
Heavy Atom Count	48
Complexity	871
Defined Atom Stereocenter Count	0
SMILES	C1CN(CCOC2=CC=C3N=C4N=CC=C(C5=CC=CC(COCC=CCOCC2=C3)=C5)N4)CC1.OC(=O)CC(O)(C(=O)O)CC(=O)O |t:10,24|
InChi Key	BAHHBHSHSRTKNK-BJILWQEISA-N
InChi Code	InChI=1S/C28H32N4O3.C6H8O7/c1-2-13-32(12-1)14-17-35-27-9-8-25-19-24(27)21-34-16-4-3-15-33-20-22-6-5-7-23(18-22)26-10-11-29-28(30-25)31-26;7-3(8)1-6(13,5(11)12)2-4(9)10/h3-11,18-19H,1-2,12-17,20-21H2,(H,29,30,31);13H,1-2H2,(H,7,8)(H,9,10)(H,11,12)/b4-3+;
Chemical Name	2-hydroxypropane-1,2,3-tricarboxylic acid;(16E)-11-(2-pyrrolidin-1-ylethoxy)-14,19-dioxa-5,7,27-triazatetracyclo[19.3.1.12,6.18,12]heptacosa-1(24),2(27),3,5,8(26),9,11,16,21(25),22-decaene
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Toxicity/Toxicokinetics	Effects During Pregnancy and Lactation ◉ Summary of Use during Lactation No information is available on the use of pacritinib during breastfeeding. The manufacturer recommends that breastfeeding be withheld during therapy and for 2 weeks after the last dose. An alternate drug is preferred, especially while nursing a newborn or preterm infant. ◉ Effects in Breastfed Infants Relevant published information was not found as of the revision date. ◉ Effects on Lactation and Breastmilk Relevant published information was not found as of the revision date.
References	[1].SB1518, a novel macrocyclic pyrimidine-based JAK2 inhibitor for the treatment of myeloid and lymphoid malignancies. Leukemia. 2011 Nov;25(11):1751-9. [2].Pacritinib (SB1518), a JAK2/FLT3 inhibitor for the treatment of acute myeloid leukemia. Blood Cancer J. 2011 Nov;1(11):e44. [3].Results of a phase 2 study of pacritinib (SB1518), a JAK2/JAK2(V617F) inhibitor, in patients with myelofibrosis. Blood. 2015 Apr 23;125(17):2649-55.
Additional Infomation	Pacritinib citrate is the citrate salt of pacritinib. It has a role as an antineoplastic agent and an EC 2.7.10.2 (non-specific protein-tyrosine kinase) inhibitor. It contains a pacritinib(1+). Pacritinib Citrate is the citrate salt form of pacritinib, an orally bioavailable inhibitor of Janus kinase 2 (JAK2), the JAK2 mutant JAK2V617F and FMS-like tyrosine kinase 3 (FLT3; CD135; STK1; FLK2), with potential antineoplastic activity. Upon oral administration of pacritinib citrate, pacritinib competes with JAK2 and the JAK2 mutant JAK2V617F for ATP binding, which may result in inhibition of JAK2 activation, inhibition of the JAK-signal transducer and activator of transcription (STAT) signaling pathway, and the induction of apoptosis. In addition, pacritinib targets, binds to and inhibits the activity of FLT3. This inhibits FLT3-mediated signaling and the proliferation of FLT3-expressing cancer cells. JAK2, often upregulated or mutated in a variety of cancer cells, plays a key role in tumor cell proliferation and survival. The JAK2V617F gain-of-function mutation involves a valine-to-phenylalanine modification at position 617. The JAK-STAT signaling pathway is a major mediator of cytokine activity. FLT3, a class III receptor tyrosine kinase (RTK), is overexpressed or mutated in most B-lineage neoplasms and in acute myeloid leukemias. In addition, JAK2 and FLT3 play a key role in the regulation of the inflammatory response and dendritic cell (DC) proliferation, differentiation and function. Inhibition of JAK2- and FLT3-mediated signaling may suppress the generation and differentiation of DCs, and may regulate inflammatory and immune responses. See also: Pacritinib (has active moiety).

Solubility Data

Solubility (In Vitro)

Typically soluble in DMSO (e.g. 10 mM)

Solubility (In Vivo)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples. Injection Formulations (e.g. IP/IV/IM/SC) Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] *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. Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline) Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline) Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline) Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil) Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Oral Formulations Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). Oral Formulation 3: Dissolved in PEG400 Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose Oral Formulation 6: Mixing with food powders Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.5044 mL	7.5222 mL	15.0444 mL
	5 mM	0.3009 mL	1.5044 mL	3.0089 mL
	10 mM	0.1504 mL	0.7522 mL	1.5044 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.