Manufacture of GMP compliant functional adenovirus specific T cell therapy for treatment of post transplant infectious complications.
BACKGROUND AIMS In pediatric patients, adenovirus (ADV) reactivation after allogeneic hematopoietic stem cell transplantation (allo HSCT) is a major cause of morbidity and mortality. For patients who do not respond to antiviral drug therapy, a new treatment approach using ADV specific T cells can present a promising alternative. Here we describe the clinical scale Good Manufacturing Practice (GMP) compliant manufacture and characterization of 40 ADV specific T cell products, Cytovir ADV, which are currently being tested in a multi center phase I/IIa clinical trial. This process requires minimal intervention, is high yield, and results in a pure T cell product that is functional. METHODS Mononuclear cells (2 x 10(7) were cultured in a closed system in the presence of GMP grade ADV peptide pool and cytokines for 10 days. On day 10, the T cell product was harvested, washed in a closed system, counted and assessed for purity and potency. Additional characterization was carried out where cell numbers allowed. RESULTS Thirty eight of 40 products (95% met all release criteria. Median purity of the cell product was 88.3% CD3+ cells with a median yield of 2.9 x 10(7) CD3+ cells. Potency analyses showed a median ADV specific interferon (IFN)g response of 5.9% of CD3+ and 2345 IFNg spot forming cells/million. CD4 and CD8 T cells were capable of proliferating in response to ADV (63.3 and 56.3% respectively) These virus specific T cells (VST) were heterogenous, containing both effector memory and central memory T cells. In an exemplar patient with ADV viremia treated in the open ASPIRE trial, ADV specific T cell response was detected by IFNg enzyme linked immunospot from 13 days post infusion. ADV DNA levels declined following cellular therapy and were below level of detection from day 64 post infusion onward. CONCLUSIONS The clinical scale GMP compliant One Touch manufacturing system is feasible and yields functional ADV specific T cells at clinically relevant doses.
Cytotherapy