Abstract P4-13-04: Autologous dendritic cells vaccines combined with neoadjuvant chemotherapy increase total pCR in stages II-III non-overexpressing HER2 breast cancer patients and induce phenotypic changes in peripheral blood

Background Based on the synergistic effect between immuno- and chemotherapy (CT), we have elaborated an autologous vaccine with dendritic cells loaded with patients´ own tumor antigens (lysate), and we have already demonstrated that the addition of the vaccines to a standard neoadjuvant CT schedule has increased total pCR (breast+ axilla) in stages II-III non-overexpressing HER2 breast cancer patients (Santisteban M, SABCS 2012). Both cohorts, the control (C) and the vaccinated (V) were well balanced related to demographic characteristics. Toxicity has been similar in both the C and the V cohorts. Moreover, we have analyzed the phenotypic changes in peripheral blood induced by the vaccine and its correlation with pathologic responses. Indeed, we have studied if the amount of lysate used to load the dendritic cells or the total dendritic cell numbers received by the patients in the first five doses (before surgery) is correlated with pCR Methods Twenty-eight patients with stage II-III HER2 negative breast cancer have started on sequential neoadjuvant CT based on dose dense antracyclines (E 100mg/m2 and C 600 mgr/m2) x4 cycles plus GM-CSF followed by taxanes (DOC 75-100 mgr/m2) x4 cycles plus vaccination. The C historic cohort was composed of thirty patients who received the same treatment except for the absence of the vaccines. Vaccine calendar was started after the 4th EC and alternated with DOC and as maintenance up to a maximum of a 2 year-period. The first 5 vaccines were administered before breast surgery. Changes in different lymphocytes populations were measured in peripheral blood of patients at different points by flow cytometry (absolute cell counts). To date, twenty-one patients have both determinations of lymphocyte subpopulations before the 1st and the 6th vaccine. Paired samples t-tests and Fisher exact were used Results pCR was superior in the V cohort (24% versus 3.3%, p = 0.04). Lymphocyte subpopulations were measured in peripheral blood (cells/uL) and a stimulation of the immune system was found after the 5 vaccines schedule at the time of surgery as follows: NK (p<0.001), T cytotoxic CD8 (p = 0.018), T helper CD4 (p = 0.04), CD19 (p = 0.001), HLADRCD8 (p = 0.007), CD16CD8 (p = 0.003), HLADRCD4 (p<0.001), CD16CD4 (p = 0.008) and T regulators lymphocytes (p = 0.004). We did not find any differences among CD57CD8 (p = 0.17), CD56CD8 (p = 0.11), CD57CD4 (p = 0.45) and CD56CD4 (p = 0.65). We neither see correlation among the amount of lysate to load dendritic cells and the tpCR (p = 0.09) nor the amount of dendritic cells (summatory of 5 vaccines) administered intradermally and the pCR (p = 0.59) Conclusions Immunotherapy added to standard neoadjuvant CT could improve total pCR in stage II-III non-overexpressing HER2 breast cancer patients. After 5 doses of vaccination plus chemotherapy, we can observe phenotypic changes in peripheral blood: some immune system subpopulations increased statistically after the treatment in vaccinated patients. Neither the amount of lysate nor the number of dendritic cells used in the five first vaccines significantly correlated with the pRC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-13-04.

[Idiotype vaccines in the treatment of follicular lymphoma: current status and future perspectives]

Follicular lymphoma is the second most prevalent non-Hodgkin lymphoma, representing 20% of all lymphomas. Follicular lymphoma is an indolent disease with a slow progression in which, although exhibiting a good response to treatment, relapse is very frequent and complete remission is not easy to maintain. Therefore, the disease is regarded as incurable. The search for new therapeutic strategies, together with a better understanding of the immune system, has led to the emergence of a new treatment named immunotherapy. Follicular lymphoma is a malignancy suitable for this kind of treatment given the fact that it is characterized by presenting a unique tumour-specific antigen: the idiotype of the monoclonal immunoglobulin displayed on the membrane of tumour cells. Several studies have been conducted to test immunotherapy as complementary to conventional treatment. In a previous study by our group, a clear benefit was evident is obtained after idiotypic vaccination, when an adequate immunization of the patient is obtained, in comparison to chemotherapy alone. In this sense, analysis is needed of whether idiotypic vaccination can produce not only long-lasting and complete remission, but even cure. It would be of great interest to consider an optimisation of the experimental design of clinical trials, an improvement of vaccine production, and the study of the molecular mechanisms of the tumour cell which modify the target immunoglobulin.

Anti-idiotype antibodies in cancer treatment

As a cancer immunotherapy tool, idiotypes (Ids) have been used in different ways over the last three decades, depending on the actual human tumor cell target. It all started with passive, monoclonal, anti-Id antibody treatment of B-cell lymphoma, a setting in which results were tantalizing, but logistics unsustainable. It then moved toward the development of anti-Id vaccines for the treatment of the same tumors, a setting in which we have recently provided the first formal proof of principle of clinical benefit associated with the use of a human cancer vaccine. Meanwhile, it also expanded in the direction of exploiting the antigenic mimicry of some Ids with Id-unrelated, tumor-associated antigens for the immunotherapy of a number of solid tumors, a setting in which clinical results are still far from being consolidated. All in all, over the years Id-based immunotherapy has paved the way for a number of seminal therapeutic improvements for cancer patients, including the development of most if not all Id-unrelated monoclonal antibodies that have recently revolutionized the field.

[Past, present and future of anti-idiotype vaccination]

Cancer vaccines are conceived as therapeutic tools, in contrast to the prophylactic vaccines used to fight against infectious diseases. Among the most potent therapeutic vaccines, anti-idiotype vaccination is directed against the tumor idiotype, the only well-characterized tumor antigen displayed in neoplastic B-cells. Anti-idiotype vaccines have demonstrated clinical benefit against follicular lymphoma and are currently being evaluated in two different phase III clinical trials. Additional emerging strategies, which include the use of dendritic cells and the production of vaccines via molecular means will surely allow us to draw important conclusions concerning the treatment of cancer patients.

[Active immunotherapy in the treatment of haematological neoplasias]

The continuous search for therapeutic approaches that improve the conventional treatments of neoplasms, together with an improved understanding of the immune system, has led in recent years to the development of Immunotherapy. Basically, a distinction can be made between two forms of immunotherapy: passive immunotherapy, which consists in the transfer of antibodies or cells previously generated in vitro that are directed against the tumour, and active immunotherapy, which attempts to activate in vivo the immune system and induce it to elaborate a specific response against the tumor antibodies. Hematological neoplasms, specifically some B lymphomas, express in their membrane an immunoglobulin that is considered a specific antigen of the tumour, which is why these diseases have become the ideal target for immunotherapy treatments. There are many alternatives, ranging from protein vaccines, which have already shown clinical benefits, to those of the second generation, which make use of the new techniques of molecular biology to increase the efficacy of the vaccines and obtain their production in a quicker and less costly way, but with which there are not yet definitive clinical results.

Identification of the B-cell tumor-specific molecular fingerprint using non-radiolabelled PCR consensus primers

BACKGROUND

The complementarity determining region 3 (CDR3) of the immunoglobulin (Ig) heavy chain variable region (VH) is the most reliable molecular fingerprint for most if not all human B cells. The nucleotide sequence encoding for any B-cell tumor-specific VH CDR3 is currently identified by PCR sequencing based on procedures involving the usage of either radioactive materials, patient/family-specific primers, or bacterial cloning.

PATIENTS AND METHODS

In six consecutive patients with follicular lymphoma we assessed the feasibility of a method that allows for identification of the tumor-specific VH CDR3 using consensus primers while avoiding both radioactive materials and bacterial cloning procedures.

RESULTS

The tumor-specific VH CDR3 was successfully identified in all six patients in nearly half the time typically required by any other method currently utilized. The feasibility of the proposed method was not significantly affected either by the tumor-specific Ig isotype, or by the tumor infiltration in the original biopsy specimen. In the three patients for whom tumor specimen-derived hybridomas were available, the tumor-specific VH CDR3 was also found in at least 8 of 10 of them.

CONCLUSIONS

The proposed method allows the ability to quickly identify the B-cell tumor-specific VH CDR3 using consensus primers while avoiding radioactive materials and bacterial cloning procedures.

Factors determining the actual received dose intensity in a program of multicyclic dose-intensive alternating chemotherapy with sequential stem cell support

Dose intensity has been related to clinical outcome in several solid tumors. We studied the influence of clinical and cellular parameters on dose intensity received in a series of 53 patients with metastatic breast cancer or advanced ovarian cancer. They received courses of cisplatin 120 mg/m(2) plus etoposide 600 mg/m(2) alternating every 14 days with ifosfamide 8 g/m(2) plus paclitaxel 200--350 mg/m(2). Blood stem cell support was administered after every course except for the first one. Patients with excellent mobilization underwent immunomagnetic selection of CD34+ cells. We found a significant inverse correlation between the CD34+ cell dose infused and the delay for the administration of the next cycle. A CD34+ cell dose between 1.5 and 5 x 10(6)/kg per cycle was found to be feasible and was followed by a median delay of 1 day (not different from doses above 5 x 10(6)/kg). Three factors independently predicted the actually received dose intensity in a multiple regression model (R(2) = 0.4): previous autologous transplantation, eligibility for immunomagnetic selection (excellent response to mobilization) and median CD34+ cell dose received along the treatment.

The increase of IFN-gamma production through aging correlates with the expanded CD8(+high)CD28(-)CD57(+) subpopulation

The use of flow cytometry to detect intracellular cytokines at the single cell level has the potential to quantify cytokine production together with the possibility of phenotypic identification of the cell population concerned. The unbalanced presence of intracellular cytokines produced by T cells has been recognized in some pathological conditions. To better address this issue, we studied the production of IFN-gamma and IL-4 in CD4(+) and CD8(+high) T cells in healthy donors of a broad range of age (17-62 years). Given that an increase of IFN-gamma and IL-4 with aging had been reported by some authors in healthy controls, we have performed a multivariate analysis to assess the intrinsic role of aging or of other external factors, such as chronic antigenic exposures (i.e., viruses), over the cytokine production of phenotypically characterized T cells. In this respect we show that, mainly in CD8(+high) T cells, the production of IFN-gamma is directly correlated with age. Besides, the cytokine production correlates with the CD8(+high)CD28(-)CD57(+) T-cell population, which we have recently reported elevated in aged individuals. Perhaps this T-cell subpopulation plays a regulatory role as a Tc1 response in aging individuals.

Clinico-pathologic, immunohistochemical, and TUNEL study in early cardiac allograft failure

Early cardiac allograft failure (ECAF) was defined as acute allograft failure in the early transplant period. The aim of this study is to elucidate the clinicopathological and immunohistochemical characteristics and the role of apoptosis in ECAF in nine patients. We reviewed preoperative clinical data and morphological data at the time of autopsy or retransplantation. We also performed TUNEL assay and immunohistochemistry to study fibronectin and tubulin beta-II. The average recipient and donor age was 48 +/- 10.3 and 28 +/- 7.11 respectively. Seven patients died at a mean time of 26 hours. The remaining two patients underwent retransplantation and are alive. The mean cold ischemic time was 124. 1 +/- 44.5 minutes. No patient had a panel reactive antibody >15% and lymphocytic crossmatch was positive in one case. All cases had grade 2-3 of coagulative necrosis, which correlated positively with fibonectin accumulation in myocyte cytoplasm, and cytoplasmic tubulin loss (p < 0.05). TUNEL technique showed in all cases some degree of DNA strand breaks in cardiomyocytes. Endothelium DNA strand breaks were seen in seven cases. Patients transplanted because of idiopathic dilated cardiomyopathy had a significantly higher degree of DNA strand breaks in cardiomyocytes and endothelial cells (p = 0.03 and p = 0.02) than those transplanted because of ischemic cardiomyopathy. These results indicate that ECAF may be caused by ischemic-reperfusion damage to the donor heart assessed by myocyte coagulative necrosis, fibronectin accumulation in myocytes, tubulin loss, and DNA strand breaks of cardiomyocytes and endothelium. The use of a combination of these techniques might be appropriate in the diagnosis of ECAF in endomyocardial biopsies when it is suspected clinically.

Cytokine flow cytometry differentiates the clinical status of multiple sclerosis (MS) patients

In this study we have examined intracellular cytokines in peripheral blood mononuclear cells (PBMC) of MS patients by flow cytometry (cytokine flow cytometry). MS progressive patients showed an increased number of cells producing interferon-gamma (IFN-gamma) after activation with phorbol 12-myristate 13-acetate and ionomycin, compared with patients with clinically inactive forms (P < 0001) and with healthy controls (P = 0001). These cells belonged to the CD4+ and CD8+ subsets in similar proportions. Clinically inactive patients showed a lower level of cells producing IL-2 than controls (P = 0.03) and active MS patients (P = 0.03). Most IL-2-producing cells were CD4+ lymphocytes, although a small part of the IL-2 was also produced by CD8+ cells. The percentage of cells producing simultaneously IL-2 and IFN-gamma was increased in active MS and they were mainly CD4+ lymphocytes. No differences in the production of IL-4 were observed between groups. However, we found an increased IL-10 production in clinically active MS patients (P = 0.03). Treatment with IFN-beta of active MS patients showed lower levels of cytokines when compared with untreated MS patients. This methodological approach could help in the follow up and therapeutic monitoring of MS patients.

Progressive decrease of CD8high+ CD28+ CD57- cells with ageing

An age-dependent decrease in T cell responsiveness to CD28 costimulation has been described. In order to test the hypothesis that an age-related decrease in CD28 expression by CD8+ T lymphocytes might be involved, we analysed 67 healthy donors ranging in age from 15 to 69 years for their CD8+ T cell expression of CD28 and CD57. We found a statistically significant decrease of CD28 expression through ageing and a significant increase of CD57 expression, both markers being mutually exclusive. Given that cytomegalovirus (CMV) is reported to induce CD57 expression, and since the carrier status for this ubiquitous virus increases with age in the general population, it seemed essential to evaluate whether the phenotypic age-related changes described in CD8high+ cells were not influenced by the CMV carrier status of the individuals. Accordingly, we performed a multivariate analysis to assess the independent association of age and CMV carrier status with CD28 and CD57 expression in CD8high+ cells. Results showed that the progressive decrease in CD8high+ CD28+ CD57- cells was associated only with age, while the expansion of the CD8high+ CD28- CD57+ subset depended both on age and CMV, although mainly on age. We conclude that ageing is accompanied by a progressive loss of CD28 expression in CD8+ T cells and a reciprocal enhancement of CD57 expression, both facts being probably related to the repeated antigenic stimulation occurring throughout life.