Implementation of Highly Sophisticated Flow Cytometry Assays in Multicenter Clinical Studies: Considerations and Guidance

Abstract

Flow cytometry is increasingly becoming an important technology for biomarkers used in drug discovery and development. Within clinical development flow cytometry is used for the determination of PD biomarkers, disease or efficacy biomarkers or patient stratification biomarkers. Significant differences exist between flow cytometry methodology and other widely used technologies measuring soluble biomarkers including ligand binding and mass spectrometry. These differences include the very heavy reliance on aspects of sample processing techniques as well as sample stabilization to ensure viable samples. These differences also require exploration of new approaches and wider discussion regarding method validation requirements. This paper provides a review of the current challenges, solutions, regulatory environment and recommendations for the application of flow cytometry to measure biomarkers in clinical development.

Interlaboratory comparison of the TransFix®/EDTA Vacuum Blood Collection tube with the 5 mL Cyto‐Chex® BCT

“…For the TVT, its utility has already been described in this fashion in publications such as Poirier et al (9) and Sommer et al (14). Regression analysis results showed that there was only one case where the correlation coefficient (r value) failed to meet the ≥0.90 target (TVT vs BD = 0.89 for CD16/56 on Day 11) for both devices.…”

“…These results highlight that both devices can be used in a capacity where a centralized analysis laboratory for immunophenotyping is required for clinical development purposes. For the TVT, its utility has already been described in this fashion in publications such as Poirier et al (9) and Sommer et al (14).…”

Cyt‐Geist: Current and Future Challenges in Cytometry: Reports of the CYTO 2018 Conference Workshops

“…Several variables such as sample/specimen choice and preparation, instruments setup and alignment, and data acquisition and analysis impact the outcome and reliability of large scale multicenter studies involving FCM; as identified by the survey and the live discussions. The main outcomes and suggestions from the WS were: Control of sample stability (from few hours to several days) is a critical factor in choosing a distributed processing approach and several methods to enhance sample stability are well documented and should be consulted . Lab‐to‐lab variations in sample processing and analyses were considered major sources of data variability resulting from subjective analyses along with the potential variability introduced by the use of multiple instruments and operators. The need for access to disease‐state samples for use in assay development and as control material. Suitable samples could come from commercial vendors, clinical partner networks, or the creation of biobanks of disease samples. …”

“…• Control of sample stability (from few hours to several days) is a critical factor in choosing a distributed processing approach and several methods to enhance sample stability are well documented and should be consulted (93,94). • Lab-to-lab variations in sample processing and analyses were considered major sources of data variability resulting from subjective analyses along with the potential variability introduced by the use of multiple instruments and operators.…”

“…Additional samples need to be included as controls both for the stimulation and for correct gating of the population of interest . Shipping of a sample to a central lab for inducible biomarker testing presents an additional challenge in that even though the cells' immunophenotypes do not change, their ability to respond to a stimulus might be compromised due to travel .…”