Development and Validation of an Ultra-Sensitive UPLC-MS/MS Method for Quantification of Monomethyl Auristatin E in Cynomolgus Monkey Plasma: Application to Pharmacokinetic Study

◢ Bioanalysis. 2026 Mar 9:1-7. doi: 10.1080/17576180.2026.2641573. Online ahead of print.

Bing Zhang ¹, Lei Zhang ¹, Yanfeng Liu ¹, Weimin Hu ², Rui Diao ¹, Lili Xing ², Yi Tao ², Liang Shen ²

¹DMPK Department, Lab Testing Division, WuXi AppTec Co., Ltd, Nantong, Jiangsu, China.

²DMPK Department, Lab Testing Division, WuXi AppTec Co., Ltd, Shanghai, China.

Abstract

Introduction: Antibody-drug conjugates (ADCs) represent a cutting-edge approach in cancer therapy, with monomethyl auristatin E (MMAE) frequently used as a payload in ADC development. We have established a novel bioanalytical method characterized by high sensitivity, accuracy, and efficiency for quantifying MMAE in cynomolgus monkey plasma.

Methodology: MMAE was extracted using liquid-liquid extraction (LLE) and quantified by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Results: The method exhibited excellent linearity across a concentration range of 5 to 3000 pg/mL (r ≥ 0.99) in cynomolgus monkey plasma, it fulfilled precision (CV ≤ 15%, 20% for lower limit of quantification (LLOQ)) and accuracy (83.98-112.75%) criteria according to meeting validation requirements per regulatory bioanalytical validation guidelines.

Conclusion: This validated method is instrumental in exploring the in vivo pharmacokinetic profile of ADC and elucidating their exposure-response dynamics.

Keywords: Antibody-drug conjugates; LC-MS/MS; bioanalysis; method validation; monomethyl auristatin E; pharmacokinetics.