P505-15 hydrochloride

Biological Activity

P505-15 (also known as PRT062607) is a highly specific and potent, orally bioavailable small molecule spleen tyrosine kinase (Syk) inhibitor (IC50 = 1 nM) with anti-Syk activity that is at least 80-fold greater than its affinity for other kinases. P505-15 potently inhibited B cell antigen receptor-mediated B cell signaling and activation (IC50 0.27 and 0.28 μM, respectively) and Fcε receptor 1-mediated basophil degranulation (IC50 0.15 μM) in human whole blood. Similar levels of ex vivo inhibition were measured after dosing in mice (Syk signaling IC50 0.32 μM). P505-15 (PRT062607) decreased cell viability in NHL and CLL. Oral administration of P505-15 produced dose-dependent anti-inflammatory activity in two rodent models of rheumatoid arthritis. In addition, combination treatment of primary CLL cells with P505-15 plus fludarabine produced synergistic enhancement of activity at nanomolar concentrations.

Customer Product Validations & Biological Datas

	Source	J Pharmacol Exp Ther (2013). Figure 1. P505-15
	Method	flow cytometry
	Cell Lines	Ramos cells
	Concentrations	2 μM
	Incubation Time	72 h
	Results	These data are consistent with previous observations that P505-15 is a selective and potent inhibitor of Syk, with no appreciable activity against other BCR-related kinases

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of Compound A used for a mouse (20 mg/kg) to a dose based on the BSA for a rat, multiply 20 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for Compound A of 10 mg/kg.

Chemical Information

References

[1] Spurgeon SE, et al. J Pharmacol Exp Ther. The selective SYK inhibitor P505-15 (PRT062607) inhibits B cell signaling and function in vitro and in vivo and augments the activity of fludarabine in chronic lymphocytic leukemia.

[2] Coffey G, et al. J Pharmacol Exp Ther. Specific inhibition of spleen tyrosine kinase suppresses leukocyte immune function and inflammation in animal models of rheumatoid arthritis.