| Autor: |
Canil G; Immunopathology and Cancer Biomarkers Unit, Centro di Riferimento Oncologico (CRO), IRCCS Aviano, 33081 Aviano, Italy. giuseppe.corona@cro.it., Miolo G; Medical Oncology and Cancer Prevention Unit, Centro di Riferimento Oncologico di Aviano (CRO), IRCCS, 33081 Aviano, Italy., Simula M; Clinical Pathology Unit, ASFO General Hospital, 33170 Pordenone, Italy., Rupolo M; Oncohematology and Cell Therapy Unit, Centro di Riferimento Oncologico di Aviano (CRO), IRCCS, 33081 Aviano, Italy., Steffan A; Immunopathology and Cancer Biomarkers Unit, Centro di Riferimento Oncologico (CRO), IRCCS Aviano, 33081 Aviano, Italy. giuseppe.corona@cro.it., Corona G; Immunopathology and Cancer Biomarkers Unit, Centro di Riferimento Oncologico (CRO), IRCCS Aviano, 33081 Aviano, Italy. giuseppe.corona@cro.it. |
| Abstrakt: |
Daratumumab, a pivotal treatment for multiple myeloma, exhibits considerable inter-patient variability in pharmacological clinical outcomes, likely attributed to serum concentration that may underscore the need for its therapeutic drug monitoring. This study aims to develop and validate a straightforward analytical method for quantifying daratumumab in serum, focusing on intact light chain determination, using liquid chromatography high-resolution mass spectrometry. The sample preparation involved immunoglobulin enrichment using Melon gel followed by a reduction step to dissociate the light from the heavy chains of immunoglobulins. The latter were then separated using a MabPac RP 2.1 × 50 mm chromatographic column and the intact light chains were detected and quantified using a Q Exactive Orbitrap mass spectrometer operating in ESI-positive ion mode at 17 500 resolution. The method demonstrated excellent linearity ( R 2 > 0.992) across a serum concentration range of 100 to 2000 μg mL -1 and good precision and accuracy: intra- and interday relative errors ranged from -5.1% to 6.5%, with a relative standard deviation of less than 5.8%. Clinical suitability was confirmed by analyzing 80 clinical samples from multiple myeloma patients treated with 1800 mg of daratumumab. 99% of the samples fell within the analytical range with a mean daratumumab concentration evaluated before the next administration ( C trough ) of 398 μg mL -1 . These findings highlighted that intact light chain monoclonal antibody quantification could be a valid and robust alternative to either immunoassays or to LC-MS/MS targeting peptides for measuring daratumumab in clinical samples, positioning it as a suitable method for therapeutic drug monitoring applications. |
