Bioanalysis最新文献

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) has transformed molecular biology through its precise gene-editing capabilities. Beyond its initial applications in genetic modification, CRISPR has emerged as a powerful tool in diagnostics and biosensing. This review explores its transition from genome editing to innovative detection methods, including nucleic acid identification, single nucleotide polymorphism (SNP) analysis, and protein sensing. Advanced technologies such as SHERLOCK and DETECTR demonstrate CRISPR's potential for point-of-care diagnostics, enabling rapid and highly sensitive detection. The integration of chemical modifications, CRISPR-Chip technology, and enzymatic systems like Cas12a and Cas13a enhances signal amplification and detection efficiency. These advancements promise decentralized, real-time diagnostic solutions with significant implications for global healthcare. Furthermore, the fusion of CRISPR with artificial intelligence and digital health platforms is paving the way for more accessible, cost-effective, and scalable diagnostic approaches, ultimately revolutionizing precision medicine.

Background: Technologies such as ELISA, MSD, and Gyrolab have been employed for quantifying protein therapeutics in clinical trials. However, these technologies have limitations with dynamic range often requiring multiple dilution steps, introducing potential errors and variability.

Results/methodology: A pharmacokinetics assay was successfully developed on the NUcleic acid Linked Immuno-Sandwich Assay (NULISA) platform with a concentration dynamic range exceeding 6 logs. This enabled assessment of all clinical samples across different concentrations with a single dilution, yielding results with good correlation to ELISA and Gyrolab.

Conclusions: NULISA technology offers high sensitivity, full automation, and a wide dynamic range, streamlining assay development and optimization, simplifying sample analysis, minimizing errors, and increasing throughput.

Background: Commonly, ligand-binding platforms are being used for immunogenicity assessment, but with the recent advent of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for protein quantification, this technology has become an alternative for the measurement of anti-drug antibodies (ADAs), when combined with an immunocapture step to extract them out of the biological sample.

Method: The monoclonal antibody adalimumab was immobilized on magnetic beads to isolate ADAs against this drug from serum samples. Multiple repetitions of immunopurification were used to minimize nonspecific binding and improve drug tolerance while maintaining sufficient recovery. A subsequent tryptic digestion released peptides, from which unique peptide sequences, originating from the constant region of seven ADA subclasses, were selected. These were then analyzed by LC-MS/MS against (unextracted) subclass-specific reference standards for semi-quantification.

Results: With two immunocapture and two immunopurification steps, the method simultaneously measures the ADA subclasses IgG1, IgG2, IgG3, IgG4, IgM, IgE and IgA within their relevant ranges, with good repeatability and drug tolerance, and limited interference of endogenous immunoglobulins. The method was successfully applied for the analysis of serum samples of subjects dosed with adalimumab.

Conclusion: Hybrid LBA-LC-MS/MS is a viable platform for measuring ADAs and adds value, especially when ADA isotyping is needed.

Background: Circulating tumor DNA (ctDNA) is a promising biomarker for cancer prognosis and drug development. A major challenge in the ctDNA determination method is discriminating ctDNA from highly similar but significantly more abundant wild-type DNA sensitively and accurately.

Method: An ultrasensitive qPCR method termed Triple Enrichment Amplification of Mutation PCR (TEAM-PCR) was developed to detect EGFR T790M mutation.

Results: EGFR T790M was quantified over the assay range of 25-10⁶ copies/reaction in the presence of 10⁶ wild-type copies. This method was fully validated following the essential bioanalysis guidance, with the limit of detection (LOD) being five copies/reaction.

Conclusion: This study established and validated a qPCR-based strategy to detect EGFR T790M mutation with ultra-high sensitivity and reliability.

Aims: Polyethylene glycol (PEG) is used in many applications including drug development. Due to exposure to environmental products, there is a high prevalence of preexisting anti-PEG antibodies in the global human population. The presence of anti-PEG antibodies is a concern for potentially reducing the efficacy of therapeutics after administration and represents a risk of safety events after exposure to PEGylated drug products. We developed and validated a creative and sensitive method for the detection of anti-PEG antibodies in human serum to support clinical programs for PEGylated drugs.

Methods: In this method, biotin-PEG streptavidin beads were used to extract anti-PEG antibodies from human serum for analysis in an anti-PEG ELISA assay. The same serum sample was analyzed in an anti-drug antibody assay.

Results: The anti-PEG antibody assay was validated with a screening cut point of 1.41 normalized signal, confirmatory cut point of 32.2% inhibition, sensitivity of 7.81 ng/mL and sufficient reproducibility, selectivity, and drug tolerance in accordance with the FDA 2019 Immunogenicity guidance.

Conclusion: This method of removal of anti-PEG antibodies enables the use of a single sample to detect anti-drug and anti-PEG antibodies to support drug development programs.

Following up on our most recent discussion paper focusing on the continued regulatory challenges for bioanalysis of biotherapeutic and biomarker proteins with LC-MS/MS, the European Bioanalysis Forum reports back on their internal discussions on and experience with method development for biotherapeutic and biomarker proteins in research and regulated bioanalysis. Due to the broad array of topics discussed, this information is spread over two research papers, where one focusses on the fundamental principles on which the technology is built (i.e., the what?) and another on the practical considerations (i.e., the how). In this paper, we discuss 'the what'. Both papers should be helpful for the bioanalytical community to better understand the challenges and provide an insight on why bioanalysis of biotherapeutic and biomarker proteins with LC-MS/MS should not be compared with the more traditional LC-MS/MS assay for small molecules or ligand binding assays for biotherapeutics.

The ICH M10 guideline establishes global standards for bioanalytical method validation for pharmacokinetic assays, focusing on data reliability and accuracy across studies. A significant component is cross-validation, which should be performed to ensure data comparability when multiple methods or laboratories are involved in a single study or across studies where comparison will be performed. However, ICH M10 does not specify acceptance criteria for cross-validation, creating challenges for the industry because traditionally many laboratories have always utilized acceptance criteria to "pass" or "fail" the study. This editorial discusses how bioanalytical labs should conduct cross-validation for PK assays post-ICH M10, highlighting the role of statistical methods and the need for close collaboration with clinical pharmacology and biostatistics departments. Proper implementation and strategic focus on relevant studies are essential for effective cross-validation.

Aims: Gastrointestinal stromal tumors (GISTs) account for about 80% of the mesenchymal tumors of the GI tract. About 5000-6000 patients are diagnosed in the United States (US) alone, and up to 14.5 cases per million discovered in Europe annually. Avapritinib (AVP) is a potent selective targeted medication that has been recently approved, by the US Food and Drug Administration, in 2020 for treatment of GISTs. AVP is currently considered the first-line treatment for mutant GIST, which is resistant to other medications. This in turn stimulates the need for fast, green, and efficient methods for routine AVP estimation in quality control and clinical studies.

Materials and methods: The proposed approach designs a spectrofluorimetric tool to estimate AVP in different matrices, based on a nucleophilic substitution reaction. A highly fluorescent product was measured at 535 nm following excitation at 470 nm. The research procedure was bioanalytically validated within AVP range between 80 and 900 ng mL^-1, where the limit of quantitation (LOQ) was 15.78 ng mL^-1.

Conclusion: The developed approach was successfully applied to investigate AVP in content uniformity testing of tablet dosage forms, and biological plasma in AVP pharmacokinetic study. The proposed approach could be recommended for AVP therapeutic drug monitoring.