Serial Assessment Of Circulating T Lymphocyte Phenotype And Receptor Repertoire During Treatment Of Non-Muscle Invasive Bladder Cancer With Adoptive T Cell Immunotherapy

Recurrence and progression of non-muscle-invasive bladder cancer (NMIBC), frequent despite the availability of multiple treatment modalities, may be partly explained by the presence of immunosuppressive cell populations. We hypothesized that progression of disease could be prevented by the administration of an activated T cell immunotherapy (ACT) at time points when immunosuppressive populations increased in peripheral blood. In an N-of-1 study, a patient with multiple primary bladder high grade urothelial carcinomas, previously treated with standard local resection and chemotherapy but with evidence of progression, received ACT consisting of dendritic cells mixed with cytokine induced killer cells (DC/CIK), intravenously 18 times over a 6 year period at indicated time of observed increases in peripheral blood immunosuppressive CD8(+)/CD28(-) cells. Peripheral blood was analyzed for T cell phenotype by flow cytometry, T cell receptor (TCR) repertoire, and circulating tumor DNA (ctDNA) by next generation sequencing (NGS) at the time of each infusion. Cystoscopy and pelvic CT scans were performed at routine intervals to assess clinical status of disease. There has been no recurrence or metastasis of urothelial carcinoma. Peripheral blood cytotoxic T cells and unique TCR clones increased and suppressive T cell populations decreased after DC/CIK infusions evidenced by the two more proof-of concept cases. ctDNA analysis detected mutations in six genes (ARID1B, MYCN, CDH23, SETD2, NOTCH4 and FAT1) which appeared at different times, but all of them disappeared after the DC-CIK infusions. These data suggest that DC/CIK infusions may be associated with beneficial changes in T cell phenotype, TCR repertoire, decreases in circulating tumor DNA and sustained recurrence-free survival.