Validation of high-sensitivity assays to quantitate cerebrospinal fluid and serum β-galactosidase activity in patients with GM1-gangliosidosis.

GM1-gangliosidosis (GM1) is a lysosomal storage disorder caused by mutations in the galactosidase beta 1 gene () that leads to reduced β-galactosidase (β-gal) activity. This enzyme deficiency results in neuronal degeneration, developmental delay, and early death. A sensitive assay for the measurement of β-gal enzyme activity is required for the development of disease-modifying therapies.

Best Practices for Development and Validation of Enzymatic Activity Assays to Support Drug Development for Inborn Errors of Metabolism and Biomarker Assessment.

Aberrant or dysfunctional cellular enzymes are responsible for a wide range of diseases including cancer, neurodegenerative conditions, and metabolic disorders. Deficiencies in enzyme level or biofunction may lead to intracellular accumulation of substrate to toxic levels and interfere with overall cellular function, ultimately leading to cell damage, disease, and death. Marketed therapeutic interventions for inherited monogenic enzyme deficiency disorders include enzyme replacement therapy and small molecule chaperones.

A flow cytometric assay for HLA-DR expression on monocytes validated as a biomarker for enrollment in sepsis clinical trials.

Purpose: Decreased expression of HLA-DR on monocytes (mHLA-DR) is a reliable indicator of immunosuppression in patients with sepsis and is correlated with increased risk of secondary infection and mortality. A flow cytometry-based laboratory developed test for the measurement of mHLA-DR in whole blood was validated for clinical trial enrollment, which is considered medical decision-making, for patients with severe sepsis or septic shock.

Methods: The BD Quantibrite™ anti-HLA-DR/anti-monocyte reagent measures antibodies bound per cell of HLA-DR on CD14+ monocytes.

Validation of a flow cytometry-based assay to assess C5aR receptor occupancy on neutrophils and monocytes for use in drug development.

The C5a/C5a receptor (C5aR) pathway, a key component in the proinflammatory immune response, is an attractive therapeutic target since its dysregulation is implicated in a variety of autoimmune and inflammatory disorders. The objective of the present study was to validate a receptor occupancy (RO) assay for a human anti-C5aR monoclonal antibody drug candidate, NNC0215-0384 (NN0384). This flow cytometry-based assay measures the percentage (%), median fluorescence intensity (MFI), and molecules of equivalent soluble fluorochrome (MESF) of NN0384 binding to its target cells, neutrophils and monocytes, in whole blood from normal healthy donors and rheumatoid arthritis (RA) patients with clinically active disease.