Quantitative Analysis of Factor P (Properdin) in Monkey Serum Using Immunoaffinity Capturing in Combination with LC–MS/MS

AIM: Factor P (Properdin), an endogenous glycoprotein, plays a key role in innate immune defense. Its quantification is important for understanding the pharmacodynamics (PD) of drug candidate(s). RESULTS: In the present work, an immunoaffinity capturing LC-MS/MS method has been developed and validated for the first time for the quantification of factor P in monkey serum with a dynamic range of 125 to 25,000 ng/ml using the calibration standards and QCs prepared in factor P depleted monkey serum. The intra- and inter-run precision was ≤7.2% (CV) and accuracy within ±16.8% (%Bias) across all QC levels evaluated. Results of other evaluations (e.g., stability) all met the acceptance criteria. CONCLUSION: The validated method was robust and implemented in support of a preclinical PK/PD study.