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Simultaneous quantification of davalintide, a novel amylin-mimetic peptide, and its active metabolite in beagle and rat plasma by online SPE and LC-MS/MS.

BACKGROUND
Davalintide, an investigational therapeutic peptide for the treatment of obesity, is rapidly metabolized by enzymatic cleavage of its N-terminal lysine residue to produce an active des-Lys metabolite in vivo. While a sensitive ELISA assay is available, it is unable to distinguish davalintide from its metabolite. Consequently, we developed an online SPE-LC-MS/MS method for simultaneous quantification of the drug and its active metabolite in beagle and rat plasma samples and compared the resulting pharmacokinetic profiles with those determined by ELISA.


RESULTS
The total concentration of active drug measured by ELISA correlated well with the total concentration of davalintide and its metabolite using online SPE-LC-MS/MS.


CONCLUSION
The technique is a viable alternative to immunochemistry-based methods for peptide quantitation in terms of sensitivity, reproducibility and specificity, and importantly, does not require developing antibody-based reagents.