Purpose
To determine the threshold blood omeprazole concentration for the maintenance of intragastric ph of at least 4.0 after oral dosing with AGN 201904-Z, an acid-stable, chemically metered absorption derivative of omeprazole (CMA-omeprazole).
Methods
Forty healthy male subjects received 240, 480, and 640 mg AGN 201904-Z or 40 mg esomeprazole orally once-daily for 5 days in a open-label, randomized, 4-way cross-over study. These doses were estimated to deliver molar equivalent omeprazole doses of 53%, 107%, and 143% of the esomeprazole dose, respectively. Pharmacokinetic (PK) blood samples were collected at 8 timepoints following the 1st and 5th dose of each treatment. Pharmacodynamics (PD) were evaluated via 24-hr intragastric ph monitoring before treatment and after the 1st and 5th doses of each treatment. Empirical PK/PD models were constructed for AGN 201904-Z data by regressing the % time that intragastric pH ≧4.0 during a 24-hr dosing period against the duration of time that blood omeprazole concentrations were greater than 8 different concentrations over the same 24-hr period. The possible threshold concentrations evaluated ranged from 10 to 400 ng/mL. The concentration that provided the best-fit was designated the threshold concentration. The best-fit concentration and model was chosen based on the WSSR, R2, visual inspection, and AIC value.
Results
Among the possible omeprazole threshold concentrations evaluated, 50 ng/mL was the best-fit concentration value in all of the models evaluated. The final model suggests the % time intragastric pH ≧4.0 is dependent on the duration of time that blood omeprazole concentrations are maintained above 50 ng/mL. This agreed with the actual results which showed AGN 201904-Z maintained drug concentrations above 50 ng/mL longer than esomeprazole (18.0 vs. 9.2 hr), and also maintained intragastric pH>4.0 longer than esomeprazole (80.1 vs. 68.4% of 24-hr; p<0.0001).
Conclusion
The 50 ng/mL blood omeprazole concentration provided the best correlation with the percent time intragastric pH was ≧4.0 over a 24-hr dosing interval and was designated as the threshold concentration of omeprazole AGN 201904-Z, a CMA-omeprazole designed to provide sustained omeprazole exposure, was more effective than esomeprazole at maintaining 24-hour intragastric ph ≧4.0.
AGN 201904-Z, sodium {4-[5-Methoxy-2-(4-methoxy-3,5-dimethyl-pyridin-2-ylmethanesulfinyl)-benzoimidazole-1-sulfonyl]-phenoxy}-acetate
This application is based on, and claims priority under 35 U.S.C. § 120 to U.S. Provisional Patent Application No. 60/805,166, filed on Jun. 19, 2006, and which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60805166 | Jun 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11734691 | Apr 2007 | US |
| Child | 12577800 | US |