The goal of this Fast-Track STTR project is to develop a Deterministic Lateral Displacement (DLD) microfluidic device that can enrich white blood cells (WBCs) from a typical leukapheresis unit in 1 hr, for use in manufacturing cancer cellular immunotherapy. Chimeric antigen receptor T cell (CAR-T) therapy has been recommended for FDA approval to treat relapsed or refractory pediatric and young adult patients with B-cell acute lymphoblastic leukemia. There is a critical need for cost-effective automated methods to improve the efficiency and yield of large-scale enrichment of WBCs for use in manufacturing CAR-T and other cellular therapies. GPB is a pioneer in developing novel DLD microchips to process blood cells for cell analysis (19,26). GPB now proposes to develop, evaluate and commercialize a compact device in which an entire leukapheresis unit (up to 5x1010 WBCs in up to 300 ml) can be processed in a ?Leuko-stack? of disposable single-use multi-channel DLD chips to produce in 1 hr a washed cell suspension that is enriched in WBCs and depleted of red blood cells (RBCs) and platelets (PLT). In Phase I, Aim 1 is to increase cell throughput through the current prototype chips by: 1) optimizing DLD chip design and operation to increase flow rate; 2) increasing throughput by stacking plastic chips and running them in parallel (?Leuko-stacks?); and 3) translating chip production to high-volume manufacturing material such as Cyclic Olefin Polymer (COP). Final Phase I milestones to proceed to Phase II are: 1) final chip design with a flow rate of at least 25 mL/hr via a single chip, at least 70% recovery of viable WBCs and immunophenotype- defined T-lymphocytes, and ability to process cells for 1 hr without clogging; 2) Leuko-stack of at least 6 chips run in parallel, with the same output as in #1; 3) combined increases in throughput via #1 and #2 sufficient to process a 300 ml leukapheresis unit in 1 hr; 4) confirmation that the chips can be produced from COP. In Phase II, Aim 2 is to build final prototype COP plastic chip-based microfluidic device capable of processing a leukapheresis sample at 300 mL/hr.
Aim 3 is to test performance of prototypes from Aim 2 with leukapheresis aliquots and then full-size human leukapheresis samples. The final milestone of this project is to produce a set of commercial prototype Leuko-stacks that can process an entire 300-ml leukapheresis unit in 1 hr with at least 70% WBC and T-lymphocyte recovery, at least 90% depletion of RBCs, at least 80% depletion of PLTs, and at least 70% recovery of T-cell expansion capacity (as compared with the input samples) in significantly more than 50% of samples tested at 2 sites. The GPB Leuko-stack platform will preserve the advantages of DLD microfluidic cell processing over current methods, while massively increasing throughput rate and cell processing capacity, thus transitioning from analytic- to preparative-scale WBC enrichment for subsequent manufacture of CAR-T and other cell therapies.

Public Health Relevance

Targeted cellular immunotherapies for several hematologic malignancies, and potentially for solid cancers, are nearly at hand. In order to increase their availability, there is a critical need for better methods to efficiently and cost-effectively isolate large quantities of the white blood cells needed to manufacture the therapeutic cells in sufficient quantities. This project proposes to scale up a proprietary microfluidic cell processing technology to enrich white blood cells from leukapheresis harvests, the first step in engineering/manufacture of therapeutic chimeric antigen receptor T cells (CAR-T) that can cure leukemias and other cancers. Successful completion of this work will result in a well-characterized prototype for a white blood cell enrichment device that will be ready for product development and extensive testing and suitable to meet regulatory approval standards.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Small Business Technology Transfer (STTR) Grants - Phase II (R42)
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Special Emphasis Panel (ZRG1)
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Lou, Xing-Jian
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Gpb Scientific, LLC
United States
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