Improving sensitivity and drug tolerance of assays for neutralizing anti-drug antibodies to semaglutide and native GLP-1.

AIM: The purpose of this work was to optimize the sensitivity and the drug tolerance of two cell-based assays for the detection of neutralizing antibodies (nAbs) to semaglutide (a GLP-1 analogue) and to endogenous GLP-1. METHODOLOGY: The two assays were developed and validated in three distinct iterations. Enhancements in sensitivity and drug tolerance were achieved through platform optimization, sample pre-treatment and the alteration of control antibodies. RESULTS: The sensitivity and drug tolerance improved gradually with the different versions of the assays. For detection of nAbs to semaglutide, sensitivity was improved from 3,400 ng to 98 ng/ml antibody, and drug tolerance was improved from 2.5 nM semaglutide when detecting 3,400 ng/ml antibodies to 4.8-5.6 nM semaglutide when detecting 1,000 ng/ml antibody. For the endogenous GLP-1 assay, sensitivity was improved from 6,900 ng/ml to 46 ng/ml antibody, and drug tolerance improved from 1.0 nM semaglutide when detecting antibody concentration of 8,800 ng/ml to 2.5 nM semaglutide when detecting 1,000 ng/ml antibody. CONCLUSION: Key factors for enhancing the sensitivity and drug tolerance of the assays included the concentration of the drug standard for receptor activation, pre-treatment of the samples, and better understanding of the binding properties of the control antibody.