Allogeneic cell-mediated immunotherapy at the stage of minimal residual disease following high-dose chemotherapy supported by autologous stem cell transplantation

Immunotherapy with cure potential of multi-drug resistant hematologic malignancies using IL-2 preactivated intentionally mismatched donor lymphocyte

PURPOSE

Unfortunately, cure of multi-drug resistant (MDR) hematologic malignancies remains an unmet need. Donor lymphocyte infusion (DLI) following allogeneic stem cell transplantation (SCT) can sometimes eliminate multi-drug resistant leukemia but at a risk of acute and chronic graft-vs-host disease (GVHD) and procedure-related toxicity. Supported by pre-clinical experiments in animal models, we hypothesized that immunotherapy induced by non-engrafting intentionally mismatched IL-2 activated killers (IMAK) including both T & NK cells could induce safer, faster and much more effective immunotherapy while avoiding the need for SCT and the risks of GVHD.

METHODS

IMAK treatment was applied in 33 patients with MDR hematologic malignancies conditioned with cyclophosphamide 1000 mg/m² based protocol. Haploidentical or unrelated donor lymphocytes were preactivated with IL-2 6000 IU/ml for 4 days. IMAK was combined with Rituximab in 12/23 patients with CD20⁺ B cells.

RESULTS

A total of 23/33 patients with MDR (4 failing SCT) achieved complete remission (CR). First patient currently 30 years with no further treatment and 6 observed for > 5 years (2 AML; 2 multiple myeloma, 1 ALL & 1 NHL) can be considered cured. No patient developed > grade 3 toxicity or GVHD. No residual male cells were detectable among six females treated with male cells beyond day + 6, confirming that GVHD was prevented by consistent early rejection of donor lymphocytes.

CONCLUSIONS

We hypothesize that safe and superior immunotherapy of MDR with cure potential may be accomplished by IMAK, most probably in patients with low tumor burden, but that remains to be confirmed by future clinical trials.

Harnessing the power of alloreactivity without triggering graft-versus-host disease: how non-engrafting alloreactive cellular therapy might change the landscape of acute myeloid leukemia treatment

Human leukocyte antigen-mismatched leukocyte infusions outside of the context of transplantation are a promising strategy for acute myeloid leukemia. Recent studies using such non-engrafting alloreactive cellular therapy (NEACT) revealed that survival of elderly patients increased from 10% to 39% when NEACT was given following chemotherapy, and that durable complete remissions were achieved in about a third of patients with relapsed or chemorefractory disease. We review the clinical reports of different NEACT approaches to date and describe how although T-cell and NK alloreactivity could generate immediate anti-leukemic effects, long-term disease control may be achieved by stimulating recipient-derived T-cell responses against tumor-associated antigens. Other variables likely impacting NEACT such as the release of pro-inflammatory cytokines from donor-host bidirectional alloreactivity and the choice of chemotherapeutics as well as future avenues for improving NEACT, such as optimizing the cell dose and potential synergies with adjuvant pharmacologic immune checkpoint blockade, are discussed.

Liver natural killer cell inoculum for liver transplantation with hepatocellular carcinoma

PURPOSE OF REVIEW

Natural killer (NK) cells are innate immune lymphocytes. NK cells contribute to host antimicrobial and antitumor immunity. Liver transplantation in patients with hepatocellular carcinoma (HCC) has increased recently. The possibility of NK cell immunotherapy for liver cancer has been studied.

RECENT FINDINGS

Adoptive transfer of interleukin-2 (IL-2)-stimulated NK cells extracted from donor liver perfusate could increase an antitumor response without causing toxicity against 1-haplotype identical recipient intact tissues in patients with live donor liver transplant. Donor liver NK cells showed the most vigorous cytotoxicity against an HCC after in-vitro IL-2 stimulation, compared with donor and recipient peripheral blood NK cells and recipient liver NK cells. IL-2 stimulation led to an increased expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on liver NK cells. T-cell contamination and risk of graft-versus-host disease can be minimized with a T-cell depleting agent such as anti-CD3 antibody.

SUMMARY

Allogeneic NK cells might have an advantage for adoptive immunotherapy. Liver NK cells from a deceased donor liver can be used safely as adoptive immunotherapy under current good manufacturing practice conditions for the treatment of liver transplantation with HCC. IL-2-stimulated liver NK cells have strong cytotoxicity, express TRAIL and secret interferon-γ.

Control of minimal residual cancer by low dose ipilimumab activating autologous anti-tumor immunity

In this perspective article, we address the controversy regarding the safety-efficacy issue in ipilimumab trials. While the CTLA-4 blockade interrupted T-cell pathways responsible for immune down-regulation and mediated regression of established malignant tumors in a minority of patients, this has to be weighed against the immune related adverse events (irAEs) suffered by the majority. Based on two groundbreaking but neglected proof-of-principle papers that demonstrated augmented graft-vs.-malignancy (GVM) effect that reversed the relapse of malignancy without worsening the graft-vs.-host disease (GVHD) by a CTLA-4 blockade, here we suggest a therapeutic paradigm shift, which may help break the impasse and resolve this timely issue in oncology.

Adoptive immunotherapy with polyclonal T cells and natural killer cells for hematological malignancies: current status and future prospects

SUMMARY Adoptive cellular therapy with polyclonal T cells and natural killer cells are immunotherapeutic modalities being studied in solid tumors and hematological malignancies to treat disease and prevent relapse. These include unexpanded polyclonal T cells, short-term activation by cytokine into lymphokine-activated killer cells, longer term expansion by cytokine stimulation giving rise to cytokine-induced killer cells or expansion under costimulation with beads expressing anti-CD3 and anti-CD28. Similarly natural killer cells can be given with or without activation and expansion. Here we review the published work and clinical trials involving each cell type in the autologous, matched allogeneic, haploidentical and nontransplant settings, comparing and contrasting each cell type and discussing their potential applications.

Immunotherapy in high-risk chemotherapy-resistant patients with metastatic solid tumors and hematological malignancies using intentionally mismatched donor lymphocytes activated with rIL-2: a phase I study

The feasibility and safety of immunotherapy mediated by intentionally mismatched rIL-2 activated killer lymphocytes (IMAK) with no prior stem cell engraftment was investigated in patients with advanced chemotherapy-resistant hematological malignancies and metastatic solid tumors. Our goals were to maximize anti-cancer activity by using intentionally mismatched donor lymphocytes; amplify killing of target cancer cells by rIL-2 activation of killer cells in vitro and in vivo, and avoid the risk of graft-versus-host disease (GVHD) by anticipated rejection of alloreactive donor lymphocytes. Conditioning consisted of 5 days of fludarabine 25 mg/m(2) or a single dose of cyclophosphamide 1,000 mg/m(2), 2 subcutaneous injections of alpha interferon (IFN) 3 x 10(6) and COX2 inhibitors, followed by administration of IMAK (65 +/- 5 CD3(+)CD56(-); 17 +/- 5 CD3(-)CD56(+)) in conjunction with low dose subcutaneous rIL-2 (6 x 10(6) IU/m(2)/day) for 5 days for continuous activation of alloreactive donor lymphocytes prior to their anticipated rejection. Here, we present our phase 1 clinical study data in a cohort of 40 high-risk patients with metastatic solid tumors and hematological malignancies. Treatment was accompanied by some malaise and occasional self-limited fever but otherwise well tolerated on an outpatient basis. Transient engraftment of donor cells was documented in two patients and only one developed self-limited grade 1 GVHD. Among patients with chemotherapy-resistant disease, long-term progression-free survival was recorded in 5 of 21 evaluable patients with metastatic solid tumors and in four of five patients with hematological malignancies. We conclude that the proposed procedure is feasible, safe, and potentially effective, with some otherwise resistant cancer patients long-term disease-free, thus justifying larger Phase II studies in patients with hematological malignancies and metastatic solid tumors, preferably at a stage of minimal residual disease with the goal in mind to eradicate all malignant cells at an early stage of the disease.

Correlation of pretransplant and early post-transplant response assessment with outcomes after reduced-intensity allogeneic hematopoietic stem cell transplantation for non-Hodgkin's lymphoma

BACKGROUND

Chemotherapy sensitivity, defined simply as at least a partial response to chemotherapy, is an important outcome predictor for non-Hodgkin lymphoma (NHL) patients undergoing reduced-intensity allogeneic hematopoietic stem cell transplantation (allo-HCT). The authors hypothesized that further differentiation of chemotherapy sensitivity by specific response, complete remission (CR) versus partial remission (PR) versus stable disease (SD) versus progression of disease (PD), correlates with post-transplant outcomes.

METHODS

The impact of pretransplant and early (28 days) post-transplant disease response on transplant outcomes was analyzed in 63 NHL patients treated with reduced-intensity allo-HCT.

RESULTS

The 3-year event-free survival (EFS) and overall survival (OS) (median potential follow-up after reduced-intensity allo-HCT = 58 months) for all patients was 37% and 47%, respectively. The 3-year EFS based on pretransplant response was: CR = 50%; PR = 66%; SD = 18%; no patient with PD pretransplant reached 3-year follow-up. The 3-year OS based on pretransplant response was: CR = 63%; PR = 69%; SD = 45%. The 3-year EFS based on post-transplant response was: CR = 57%; PR = 32%; SD = 33%; no patient with PD post-transplant reached 3-year follow-up. The 3-year OS based on post-transplant response was: CR = 65%; PR = 43%; SD = 50%. In multivariate analyses, pretransplant response was the best predictor of EFS (P < .0001). Pretransplant response (P < .0001) and age (P = .0035) were jointly associated with OS.

CONCLUSIONS

These data suggest that NHL patients with pretransplant SD, generally considered inappropriate candidates, may benefit from reduced-intensity allo-HCT, and patients with pretransplant PD should only receive this therapy in clinical trials.

HLA-G expression in human breast cancer: implications for diagnosis and prognosis, and effect on allocytotoxic lymphocyte response after hormone treatment in vitro

OBJECTIVE

The aim of this study is to investigate clinical implications of human leukocyte antigen-G (HLA-G) expression in breast cancer.

METHODS

HLA-G expression in 235 primary breast cancer tissues was investigated using immunohistochemistry, and plasma soluble HLA-G (sHLA-G) was measured in 44 breast cancer patients using a specific HLA-G enzyme-linked immunosorbent assay (ELISA). Effects of estradiol/progesterone and their antagonists tamoxifen/RU486 on HLA-G expression in cultured breast cancer MCF-7 cells were determined by real-time polymerase chain reaction (PCR) and the ELISA. Alterations of HLA-G expression by the hormone treatments on subsequent allocytotoxic lymphocyte (allo-CTL) response were also examined.

RESULTS

In the study, approximately 66% of neoplasm lesions were identified to have positive HLA-G expression. This expression was significantly correlated with tumor size, nodal status, and clinical disease stage (P = 0.0001, 0.012, and 0.0001, respectively). Patients with positive HLA-G expression had a lower survival rate than those with negative expression (P < 0.028). Plasma sHLA-G levels were significantly higher in breast cancer patients than in healthy controls (P < 0.001), with the area under the receiver-operating characteristic (ROC) curve being 0.95. HLA-G expression in breast cancer MCF-7 cells was enhanced by estradiol/progesterone but reduced by their antagonists. Cytotoxicity studies showed that allo-CTL response in MCF-7 cells was inhibited by prior treatment with estradiol/progesterone, but was amplified by their antagonists. The effects could be restored or further strengthened by the addition of anti-HLA-G antibodies.

CONCLUSION

Our findings suggest that HLA-G may have potential clinical implications in diagnosis, prognosis, and immunotherapy of patients with breast cancer.

NK cell-mediated targeting of human cancer and possibilities for new means of immunotherapy

Insights into the molecular basis for natural killer (NK) cell recognition of human cancer have been obtained in recent years. Here, we review current knowledge on the molecular specificity and function of human NK cells. Evidence for NK cell targeting of human tumors is provided and new strategies for NK cell-based immunotherapy against human cancer are discussed. Based on current knowledge, we foresee a development where more cancers may be subject to treatment with drugs or other immunomodulatory agents affecting NK cells, either directly or indirectly. We also envisage a possibility that certain forms of cancers may be subject to treatment with adoptively transferred NK cells, either alone or in combination with other therapeutic interventions.

The second international meeting on allogeneic transplantation in solid tumors

In October 2005, the second international meeting on allogeneic transplantation in solid tumors was convened in Stresa (Italy). The aim of this second meeting was to share clinical experiences of allografting in solid tumors, to discuss preclinical data on the mechanisms of graft-versus-tumor (GVT) effect, and to review methods for more efficacious transplant approaches. On the first day, the most recent results in cancer immunotherapy were reviewed; head-to head comparisons of clinical results achieved by standard therapy and by allografting in renal, breast, and ovarian cancer were presented. On the second day, GVT mechanisms and preclinical models were examined; anecdotal reports of a GVT effect in sarcoma, pancreatic cancer, prostate cancer, colorectal cancer and lung cancer were presented; new strategies for optimizing transplant outcome were discussed, including patient selection, tumor debulking, auto-allo approaches, selective T-cell depletion, targeting with monoclonal antibodies, use of killer cell immunoglobulin-like receptor-ligand mismatched natural killer cells. In conclusion, allografting in solid tumors is feasible with limited toxicities and transplant-related mortality; a GVT effect has been documented in many different solid tumors; targeting of the immune response to the tumor by new strategies and identification of the target antigen(s) of the GVT effect are promising areas of research.