Ligand binding assay macromolecules

Desilva B, Smith W,Weiner R, et at. Recommendations for the bioanalytical method validation of ligand-binding assays to support pharmacokinetic assessments of macromolecules. Pharm. Res. (2003) 20 1885-1900. 

Kll. Korenman, S. G., Radio-ligand binding assay of specific estrogens using a soluble uterine macromolecule. J. Clin. Endocrinol. 28, 127-130 (1968). 

DeSilva, B., Smith, W., Wiener, R., Kelley, M., Smolec, J., Lee, B., Khan, M., Tacey, R., Hill, H., and Celniker, A. (2003) Recommendations for the bioanalytical method validation of ligand binding assays to support pharmacokinetic assessments of macromolecules. Pharmaceutical Research, 20, 1885 1900. 

Findlay, J.W.A. (2009) Specificity and accuracy data for ligand binding assays for macromolecules should be interpreted with caution. The AAPS Journal, 10, 433 434. 

Nowatzke, W., and Bowsher, R. (2007) A macromolecule perspective on the 3rd AAPS/ FDA workshop/conference report quantitative bioanalytical methods validation and implementation best practices for chromatographic and ligand binding assays. AAPS... 

Ligand-binding assay - hke RIA, ELISA and other types of competitive antigen -antibody-related methods - are broadly apphed to detect and quantify macromolecules in biomatrices. In addition, ceU-based assays and antibody titer determinations might be additional quantification methods for macromolecules. Several of these methods have already been used and established in clinical chemistry to determine levels of endogenous substrates in the past. Thus, it is a direct approach to use similar methods in the case of measurement of for example, recombinant analogues and other suitable biopharmaceuticals. 

For each in-study run, the standard curve must satisfy criteria described in the standard-curve section however, run acceptance is based primarily on the performance of the QC samples. When using total error for ligand binding assays of macromolecules, the run acceptance criteria recommended in the precision and accuracy section requires that at least four of six (67%) QC results must be within 30% of their nominal values, with at least 50% of the values for each QC level satisfying the 30% limit. The recommended 4-6-30 rule imposes limits simultaneously on the allowable random error (imprecision) and systematic error (mean bias). If the application of an assay requires a QC target acceptance limit different than the 30% deviation from the nominal value, then prestudy acceptance criteria for precision and accuracy should be adjusted so that the limit for the sum of the interbatch imprecision and absolute mean RE is equal to the revised QC acceptance limit. 

DeSilva B, Smith W, Weiner R, et al. (2003). Recommendations for the Bioanalytical Method Validation of Ligand-binding Assays to Support Pharmacokinetic Assessments of Macromolecules. Pharmac. Res. 20(11) 1885-1900. 

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