Quantification of Pharmacokinetic Profiles of PD-1/PD-L1 Antibodies by Validated ELISAs
Sara Zalba1, Ana M Contreras-Sandoval1,2, Eva Martisova3
1Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, University of Navarra, 31008 Pamplona, Spain.
Abstract:
Immunotherapy has changed the paradigm of cancer treatments. In this way, several combinatorial strategies based on monoclonal antibodies (mAb) such as anti (a)-PD-1 or anti (a)-PD-L1 are often reported to yield promising clinical benefits. However, the pharmacokinetic (PK) behavior of these mAbs is a critical issue that requires selective analytical techniques. Indeed, few publications report data on a-PD1/a-PD-L1 exposure and its relationship with therapeutic or toxic effects. In this regard, preclinical assays allow the time profiles of antibody plasma concentrations to be characterized rapidly and easily, which may help to increase PK knowledge. In this study, we have developed and validated two in-house ELISAs to quantify a-PD-1 and a-PD-L1 in plasma collected from tumor-bearing mice. The linear range for the a-PD-1 assay was 2.5-125 ng/mL and 0.11-3.125 ng/mL for the a-PD-L1 assay, whereas the intra-and inter-day precision was lower than 20% for both analytes. The PK characterization revealed a significant decrease in drug exposure after administration of multiple doses. Plasma half-life for a-PD-1 was slightly shorter (22.3 h) than for a-PD-L1 (46.7 h). To our knowledge, this is the first reported preclinical ELISA for these immune checkpoint inhibitors, which is sufficiently robust to be used in different preclinical models. These methods can help to understand the PK behavior of these antibodies under different scenarios and the relationship with response, thus guiding the choice of optimal doses in clinical settings.
Insights
We developed validated ELISAs to quantify anti-PD-1 and anti-PD-L1 in mice plasma. This helps understand drug exposure and optimize dosing for cancer immunotherapy.
Area of Science:
- Immunology
- Pharmacology
- Analytical Chemistry
Background:
- Cancer immunotherapy utilizing monoclonal antibodies (mAbs) like anti-PD-1 and anti-PD-L1 has transformed treatment paradigms.
- Understanding the pharmacokinetic (PK) behavior of these mAbs is crucial for therapeutic and toxic effect correlation, yet data remains limited.
- Preclinical assays are vital for characterizing antibody plasma concentration profiles and enhancing PK knowledge.
Purpose of the Study:
- To develop and validate sensitive, robust in-house ELISAs for quantifying anti-PD-1 and anti-PD-L1 in preclinical plasma samples.
- To characterize the PK profiles of anti-PD-1 and anti-PD-L1 in tumor-bearing mice.
- To establish a foundation for correlating drug exposure with therapeutic outcomes in preclinical cancer models.
Main Methods:
- Development and validation of two in-house Enzyme-Linked Immunosorbent Assays (ELISAs) for quantifying anti-PD-1 and anti-PD-L1.
- Assay validation included determination of linear ranges (2.5-125 ng/mL for anti-PD-1, 0.11-3.125 ng/mL for anti-PD-L1) and precision (intra- and inter-day <20%).
- Quantification of antibody concentrations in plasma from tumor-bearing mice to assess PK parameters.
Main Results:
- Successfully developed and validated ELISAs with defined linear ranges and acceptable precision for both analytes.
- PK characterization demonstrated a significant decrease in drug exposure following multiple dose administrations.
- Determined plasma half-lives: approximately 22.3 hours for anti-PD-1 and 46.7 hours for anti-PD-L1.
Conclusions:
- This study presents the first reported preclinical ELISAs for quantifying anti-PD-1 and anti-PD-L1, suitable for diverse preclinical models.
- The developed methods provide a robust tool for understanding the PK behavior of these immune checkpoint inhibitors.
- These assays will aid in correlating drug exposure with efficacy and toxicity, guiding optimal dose selection in clinical settings.
