Cellular potencies and plasma stability of AZD8848 and its acid metabolite, AZ12432045
| Assay | AZD8848 | n | AZ12432045 | n |
|---|---|---|---|---|
| Human TLR7 (pEC50) | 7.0±0.03 | 20 | <5.0 | 6 |
| Rat TLR7 (pEC50) | 6.6±0.03 | 11 | <5.0 | 7 |
| Human TLR8 (pEC50) | <5.0 | 7 | <5.0 | 7 |
| Human IFNα (pMEC) | 8.4±0.3 | 3 | ≤5.0 | 3 |
| Human IL-5 PHA(pIC50) | 9.0±0.1 | 14 | 5.5±0.2 | 6 |
| Human IL-5 DerP1 (pIC50) | 9.7±0.3 | 7 | 5.8±0.3 | 7 |
| Human plasma stability t1/2 (min) | 0.3±0 | 2 | N/A | |
| Rat plasma stability t1/2 (min) | <0.1 | 2 | N/A |
Dose–response curves were constructed for compounds to determine activity in HEK293 cells stably expressing human TLR7, rat TLR7 or human TLR8. Activity was calculated from the release of secretory alkaline phosphatase whose expression was linked to an NF-kB promoter. Human PBMC were incubated with compound over a range of concentrations and supernatants removed at 24 h for determination of IFNα induction by ELISA. For inhibition of IL-5, PBMC were incubated with PHA for 2 days or Der p 1 for 7d in the presence of a dose range of compound and the level of inhibition was compared to stimulus alone. Data show the number of individual determinations (n) with the mean value ± SEM. Activities for all cellular assays are shown as the negative logarithm (denoted p) of the experimentally determined value where EC50 is the molar concentration giving 50% effect, MEC is the minimum molar concentration showing an effect and IC50 is the molar concentration giving 50% inhibition. Plasma t1/2 was determined by incubating AZD8848 in human or rat plasma and quantifying the disappearance of parent compound. Determinations were from 2 separate incubations with the range shown. IFNα, interferon α; IL-5, interleukin 5; N/A, not applicable; TLR7, toll-like receptor 7.