Assay lifecycle development for traditional biopharmaceuticals such as vaccines and monoclonal antibodies (MAbs) has a clearly defined pathway, from preclinical method selection, development, and optimization through the milestones in preclinical phase trials, and finally to postlicensure method evaluations, comparability, and improvements. The analytical development roadmap for nontraditional biologics such as chimeric antigen receptor (CAR) T-cell therapies and gene therapies are not as clearly defined and can present many challenges along the way. Understanding the “what, how, and when” of analytical…