Fludarabine Modulates Immune Response and Extends In Vivo Survival of Adoptively Transferred CD8 T Cells in Patients with Metastatic Melanoma

Abstract

BackgroundAdoptive T cell therapy involving the use of ex vivo generated antigen-specific cytotoxic T lymphocytes provides a promising approach to immunotherapy. It has become increasingly apparent that anti-tumor efficacy using adoptively transferred T cells is linked to their duration of in vivo persistence and can only be achieved when combined with some form of pre-infusion patient conditioning regimen. An optimal conditioning regimen that provides a positive benefit without serious toxicities has yet to be defined. We have established a unique clinical model that allows for evaluation of a given conditioning regimen on adoptively transferred T cells in humans. In this first-in-human study (FHCRC #1796), we evaluate the use of fludarabine, an FDA-approved reagent with predictable lymphodepleting kinetics and duration of action, as a conditioning regimen that promotes homeostatic upregulation of cytokines and growth signals contributing to in vivo T cell persistence.Methods/FindingsWe conducted a phase I study in patients with refractory metastatic melanoma. Patients received two infusions of a single tumor-reactive antigen-specific CTL clone expanded to 1010/m2; the first infusion was given without fludarabine conditioning, and the second CTL infusion was given after a course of fludarabine (25 mg/m2/day×5 days). This design permits intra-patient comparison of in vivo T cell persistence pre- and post-fludarabine. Nineteen CTL infusions were administered to ten patients. No serious toxicities were observed. Three of nine evaluable patients experienced minor response or stable disease for periods of 5.8–11.0 months with two additional patients demonstrating delayed disease stabilization. The median overall survival in this heavily pre-treated population was 9.7 months. Fludarabine led to a 2.9 fold improvement in the in vivo persistence of transferred CTL clones from a median of 4.5 days (range 0–38+) to 13.0 days (range 2–63+) (p<0.05). Fludarabine lymphodepletion increased plasma levels of the homeostatic cytokines IL-7 and IL-15. Surprisingly, fludarabine also increased the relative percentage of CD4+ T cells expressing the regulatory protein Foxp3.Conclusions/SignificanceLymphodepletion with fludarabine enhances transferred T cell persistence but suggest that additional improvements to optimize T cell survival and address regulatory T cells are critical in providing anti-tumor efficacy.Trial RegistrationClinicalTrials.gov NCT00317759

Increased Plasma-Immune Cytokines throughout the High-Dose Melphalan-Induced Lymphodepletion in Patients with Multiple Myeloma: A Window for Adoptive Immunotherapy

“…Several studies in mice and humans showed that homeostatic expansion is associated with faster and more efficient immune response and that immunization with tumor Ags during lymphopenia generates CD8 T cells with enhanced antitumor capacities (16,(29)(30)(31)(32). Recently, two clinical trial studies in metastatic melanoma revealed that lymphodepletion-induced high levels of circulating IL-7 and IL-15 were associated with a longer in vivo persistence of infused autologous antitumor T cells (33,34). Wallen et al made an intrapatient comparison of two consecutive infusions of T cell clones, the first without fludarabine and the second with fludarabline as a conditioning regimen.…”

“…Wallen et al made an intrapatient comparison of two consecutive infusions of T cell clones, the first without fludarabine and the second with fludarabline as a conditioning regimen. They reported median plasma IL-7 and IL-15 levels of 3 pg/ml and 6 pg/ml, respectively, at the time of the second T cell infusion (34). The persistence of T cells from the second infusion was 2.9-fold longer than that of T cells from the first infusion, underlying the benefit effect of the conditioning regimen.…”

“…A, ALC and cytokine plasma levels. Data are the mean values 6 SD of ALC, of IL-6, IL-7, and IL-15 plasma concentrations measured in six patients before HDM infusion (day 2), on the day of ASCT (day 0) on day 3 or 4, on day 6, on day 8, on day 10 or 11, on day 12 or 13, on day 14 or 15, and around 1 mo after ASCT (day [32][33][34]. The x and p indicate that the mean ALC or cytokine value is significantly different (p # 0.05) from that of day 2, using a Mann-Whitney U test for pairs.…”

Tolerance and efficacy of autologous or donor-derived T cells expressing CD19 chimeric antigen receptors in adult B-ALL with extramedullary leukemia

“…Our findings suggest that conditioning regimens combined with intensive chemotherapy may prevent life-threatening CRS by reducing tumor burdens. Despite the well-documented benefits of conditioning chemotherapy in enhancing in vivo persistence and antitumor efficacy of adoptively transferred tumor-specific T cells, 32,[35][36][37] the role of the pre-infusion conditioning regimens needs to be carefully evaluated.…”

“…40 However, it is not clear that IL-2 injections will help the transferred cytotoxic T cells, so the patients in our trial did not receive IL-2 injections. Third, a number of studies suggest plausible mechanisms for coordinate effects of chemotherapy and CART cells 41,42 in addition to the lymph-depleting effects of chemotherapy, which promote homeostatic expansion of adoptive www.tandfonline.com e1027469-7 OncoImmunology T cells, 37 including CART-19 cells. This is consistent with our finding that patients 2 and 9, who received lymphodepleting therapy, demonstrated more rapid in vivo expansion after cell infusion ( Fig.…”