The renaissance of cancer immunotherapies and the positive clinical responses observed with chimeric antigen receptor modified T cells in the hematomalignancy setting has stimulated substantial interest in monitoring immune cell activation and suppression to determine efficacy, prognosis and safety in new agent investigational trials. However, immunophenotyping capacity has been limited and required multi-test tube panels. To address the growing needs of clinical trials, we have developed three fit-for-purpose high complexity (10 or more markers) T-cell phenotyping flow cytometry panels on a qualified LSR FortessaTM platform that enables detection of up to 15 markers in a single test tube. The first panel allows identification of multiple phenotypes along the T-cell differentiation pathway, namely, T-naive (TN), T-stem cell memory (TSCM), T-effector memory (TEM) and T-central memory (TCM) and T-effector memory RA+ (TEMRA). The second panel identifies the most common helper T-cell phenotypes such as Th1, Th2, Treg, and Th17. A third panel determines the functional status of T-cells (e.g., activation vs. suppression) but also enables quantitation of important checkpoint inhibitor expression (e.g., PD-1) on T-cells of interest. These high complexity flow cytometry panels can serve as powerful tools for comprehensive examination of T-cells in a small volume of patient specimen. We believe these new flow cytometry panels will have a substantial impact on the determination of efficacy and safety correlates of immunomodulating agents administered alone or in combination to patients with leukemia.

Citation Format: Ghanashyam Sarikonda, Devika Ashok, Anil Pahuja, Jelveh Lameh, Shabnam Tangri, Naveen Dakappagari. High complexity flow cytometry panels to monitor target expression, T-cell activation and suppresssion by novel immunotherapies in hematomalignancy clinical trials. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1302. doi:10.1158/1538-7445.AM2015-1302