Asapiprant

Biological Activity

Asapiprant is a potent and selective DP1 receptor antagonist, with a Ki of 0.44 nM. Asapiprant exhibited high affinity and selectivity for the DP1 receptor. Treatment with Asapiprant in rats at 10 mg/kg significantly (P<0.05) reduces airway hyper-responsiveness (AHR), infiltration of inflammatory cells, and mucin production in bronchoalveolar lavage fluid (BALF), although treatment with Asapiprant at 0.1 mg/kg does not have a significant effect on any responses. In addition, treatment with asapiprant suppressed antigen-induced asthmatic responses, airway hyper-responsiveness, and cell infiltration and mucin production in lung. These results show that asapiprant is a potent and selective DP1 receptor antagonist, and exerts suppressive effects in the animal models of allergic diseases.

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

Effect of the potent and selective DP1 receptor antagonist, asapiprant (S-555739), in animal models of allergic rhinitis and allergic asthma.
Takahashi G, et al. Eur J Pharmacol. 2015 Oct 15;765:15-23. PMID: 26277322.