There is growing interest in tissue procurement for cancer research through autopsy. Establishing an autopsy/tissue donation programme for breast cancer research within an academic medical centre in the United States requires consideration, planning, multi-departmental collaboration and labour-intensive maintenance. It is the purpose of this paper to outline the necessary considerations in implementing and maintaining a tissue donation and autopsy programme within a breast cancer centre at a comprehensive cancer centre. Considerations of programme planning include: patient engagement, the recruitment of patients and families into the programme, the role and scope of work of the clinical coordinator, regulatory issues and the coordination with both pathology and the research team at time of death and autopsy/tissue donation. All aspects of the tissue donation/rapid autopsy programme development and implementation are discussed and illustrated through case study. An Autopsy/ Tissue Donation for breast cancer research can be successfully developed and implemented.

Increasing knowledge concerning the biology of hematologic malignancies as well as the role of the immune system in the control of these diseases has led to the development and approval of immunotherapies that are resulting in impressive clinical responses. Therefore, the Society for Immunotherapy of Cancer (SITC) convened a hematologic malignancy Cancer Immunotherapy Guidelines panel consisting of physicians, nurses, patient advocates, and patients to develop consensus recommendations for the clinical application of immunotherapy for patients with multiple myeloma, lymphoma, and acute leukemia. These recommendations were developed following the previously established process based on the Institute of Medicine’s clinical practice guidelines. In doing so, a systematic literature search was performed for high-impact studies from 2004 to 2014 and was supplemented with further literature as identified by the panel. The consensus panel met in December of 2014 with the goal to generate consensus recommendations for the clinical use of immunotherapy in patients with hematologic malignancies. During this meeting, consensus panel voting along with discussion were used to rate and review the strength of the supporting evidence from the literature search. These consensus recommendations focus on issues related to patient selection, toxicity management, clinical endpoints, and the sequencing or combination of therapies. Overall, immunotherapy is rapidly emerging as an effective therapeutic strategy for the management of hematologic malignances. Evidence-based consensus recommendations for its clinical application are provided and will be updated as the field evolves.

BackgroundNatural killer cell cytotoxicity is decreased in patients with acute myeloid leukemia in comparison to that in normal controls.Tumor-derived microvesicles present in patients' sera exert detrimental effects on immune cells and may influence tumor progression. Design and MethodsWe investigated the microvesicle protein level, molecular profile and suppression of natural killer cell activity in patients with newly diagnosed acute myeloid leukemia. ResultsThe patients' sera contained higher levels of microvesicles compared to the levels in controls (P<0.001).Isolated microvesicles had a distinct molecular profile: in addition to conventional microvesicle markers, they contained membrane-associated transforming growth factor-β1, MICA/MICB and myeloid blasts markers, CD34, CD33 and CD117.These microvesicles decreased natural killer cell cytotoxicity (P<0.002) and down-regulated expression of NKG2D in normal natural killer cells (P<0.001).Sera from patients with acute myeloid leukemia contained elevated levels of transforming growth factor-β, and urea-mediated dissociation of microvesicles further increased the levels of this protein.Neutralizing anti-transforming growth factor-β1 antibodies inhibited microvesicle-mediated suppression of natural killer cell activity and NKG2D down-regulation.Interleukin-15 protected natural killer cells from adverse effects of tumor-derived microvesicles. ConclusionsWe provide evidence for the existence in acute myeloid leukemia of a novel mechanism of natural killer cell suppression mediated by tumor-derived microvesicles and for the ability of interleukin-15 to counteract this suppression.

Interleukin-15 (IL-15) has a major role in NK-cell homeostasis. Modulation of the relative frequency and expression intensity of the NK-cell receptors by IL-15 may increase NK cell-mediated cytotoxicity in cancer patients. We investigated the receptor repertoire and measured NK-cell activity in newly diagnosed AML patients and evaluated the ex vivo effects of IL-15. The expression of the activating NK cell receptors was significantly decreased in the AML patients compared to that in NK cells of healthy donors. When NK cells obtained from AML patients were cultured with IL-15, expression of the activating receptors was significantly upregulated compared to pre-culture levels. Concomitantly, cytotoxic activity of NK cells against autologous leukemic blasts increased following IL-15 stimulation. This IL-15 induced increase in activity was blocked by neutralizing antibodies specific for the NK cell activating receptors. These pre-clinical data support the future use of IL-15 for NK cell- based therapies for AML patients.

Purpose: Regulatory CD4(+)CD25(high)Foxp3(+) T cells (Treg) control peripheral immune tolerance. Patients with cancer, including those with hematologic malignancies, have elevated numbers of Treg in the peripheral circulation and in tumor tissues. However, mechanisms of suppression and clinical significance of Treg, especially in patients with acute myelogenous leukemia (AML), has not been well defined.Experimental Design: We prospectively evaluated the phenotype, function, and mechanisms of suppression used by Treg in newly diagnosed untreated AML patients. The relationship between the frequency of circulating Treg and the disease status as well as treatment outcome was also evaluated.Results: The percentage of circulating Treg was higher (P < 0.0001) and their phenotype was distinct in AML patients relative to normal controls. Suppression mediated by Treg coincubated with proliferating autologous responder cells was also higher (P < 0.001) in AML than that mediated by control Treg. Using Transwell inserts, we showed that interleukin-10 and transforming growth factor-beta 1 production as well as cell-to-cell contact were necessary for Treg-mediated suppression. Also, the pretreatment Treg frequency predicted response to chemotherapy. Unexpectedly, patients who achieved complete remission still had elevated frequency of Treg, which mediated high levels of suppressor activity.Conclusions: Treg accumulating in the peripheral circulation of AML patients mediate vigorous suppression via contact-dependent and contact-independent mechanisms. Patients with lower Treg frequency at diagnosis have a better response to induction chemotherapy. During the post-induction period, the Treg frequency and suppressive activity remain elevated in complete remission, suggesting that Treg are resistant to conventional chemotherapy.

Abstract Abstract 2678 Poster Board II-654 Natural killer (NK) cell cytotoxicity in patients with acute myeloid leukemia (AML) is significantly decreased relative to that in normal controls (NC). However, the mechanisms responsible for low NK cell activity in AML are not known. We considered the possibility that tumor-cell-derived microvesicles (MV) mediate suppression of NK cells. MV originate from the endosomal compartment of activated normal and neoplastic cells. Evidence suggests that tumor-derived MV exert detrimental effects on cells of the immune system and may play a role in tumor progression. To determine their contribution to immune suppression in AML, MV were isolated from sera of patients newly diagnosed with AML prior to any treatment and used to evaluate MV-mediated NK cell suppression. The protein content of MV isolated using exclusion chromatography and ultracentrifugation from sera of 19 AML patients was significantly higher than that of MV isolated from sera of 25 NC (75μg±12/mL vs 1.2μg±0.4/mL, p<0.001 ). MV from AML patients were positive for membrane-associated TGFb-1 and FasL in Western blots, whereas no TGFb-1 or FasL was detected in MV from NC. For functional assays, NK cells sorted from peripheral blood of NC were cultured with MV isolated from sera of the AML patients. A significant decrease in NK cell cytotoxicity was observed after co-incubation with MV (2412 LU before vs 1640 LU after, p<0.002). Concomitantly, a decrease in the expression of the NK cell activating receptor, NKG2D, was observed (57% before vs 38% after, p<0.001). The addition of TGFb1-neutralizing antibody abrogated the effects of MV on the NK cell cytotoxicity and receptor expression. The increased levels in sera of AML patients of MV mediating potent NK cell suppression is likely to compromise anti-tumor immune responses. Therefore, modulation of the levels and functions of MV might provide new immunotherapeutic approaches in AML. Disclosures: No relevant conflicts of interest to declare.

An elevated frequency of CD4+CD25high regulatory T cells (Treg) has been reported in the peripheral blood in patients with various solid tumors and hematologic malignancies. Although the increase in Treg seems to be a characteristic feature of most tumors, the functional role of Treg and the mechanisms of suppression, especially in patients with hematologic malignancies, have been less well defined. We investigated Treg-mediated suppression and the responsible mechanisms in thirty newly diagnosed acute myeloid leukemia (AML) patients prior to any treatment and twenty five healthy donors (NC). The percentage of circulating CD4+ CD25high Treg was higher (p <0.0001) in the AML patients (4.5 ±0.2%, range 1.7–8.2%) compared to NC (1.5 ± 0.08%, range 0.9–3.1 %). To evaluate the suppressive function, CD4+CD25high T cells (S) were co-cultured with sorted, CFSE-labeled autologous CD4+CD25high T cells (R) at different S/R ratios. Suppression mediated by Treg co-incubated with proliferating autologous responders was significantly higher (p<0.001) in AML than that mediated by control Treg. To evaluate the role of cytokines produced by Treg in suppression and a need for cell-to- cell contact, transwell analysis of S/R co-cultures was performed. Co-incubation in the presence of transwell inserts (TRI) resulted in significant reduction of suppression (p<0.05), and the addition of neutralizing antibodies to IL-10 and TGF-β1 in the presence of TRI further decreased suppression mediated by Treg. These data suggest that both immunoinhibitory cytokine production and cell-to-cell contact are necessary for suppression. To explore other potential mechanisms of Treg suppression, we evaluated the expression by Treg of ectonucleotidases CD39 and CD73 and the capability of Treg to produce adenosine. CD4+CD25high T cells of AML patients had higher expression (p<0.01) of CD39 and more efficiently hydrolyzed ATP to adenosine relative to Treg in NC. These data indicate that various mechanisms of suppression may be utilized by Treg in patients with AML. The increase frequency of Treg mediating potent suppression by various mechanisms is likely to play a role in host anti-tumor immune responses. Therefore, modulation of the frequency and functions of Treg might provide new immunotherapeutic approaches in AML.

Interleukin-15 (IL-15) has been demonstrated to play a critical role in the regulation of natural killer (NK) cells. IL-15 induces the differentiation of NK cells from hematopoietic progenitors, stimulates the expansion of peripheral NK cells, and supports their survival. We investigated the role of IL-15 as a homeostatic regulator of NK cells in 29 patients diagnosed with acute myeloid leukemia (AML) and the potential role of IL-15 in enhancing the anti-tumor activity of NK cells in AML patients. The percentage of circulating NK cells was lower (p<0.0001) in the AML patients (6%± 0.7, range 1–17%) compared to the NK cells of healthy donors (12%± 1, range 9–17 %). At diagnosis the mean level of IL-15 in patient plasma was 1.9 pg/ml (range 0.03–8.9) and increased (p <0.02) to 5.2 pg/ml (range 0.06–13.4) after the completion of induction chemotherapy, when the NK levels had been reduced to zero cells/microliter. The mean level of IL-15 subsequently decreased to pre-treatment levels in the AML patients who achieved complete remission (mean 1.6 pg/ml, range 0.4–2.3). To assess effects of IL-15 on the NK cytotoxicity, we sorted NK cells from PBMC obtained from AML patients prior to treatment (at diagnosis) and cultured them in the presence of IL-15. Following IL-15 stimulation, a significant increase in NK-cell cytotoxicity against K562 targets and the patients' autologous leukemic blasts was observed (p<0.05) as was up-regulation in expression of the activating natural cytotoxicity receptors, NKp30 and NKp46 and the C-type lectin receptors NKG2D and NKG2C (p<0.02–0.001). Addition of blocking antibodies to the activating receptors reduced NK-cell cytotoxicity. We determined that IL-15, a homeostatic NK-cell cytokine, increases after severe depletion of NK cells following intensive chemotherapy and this leads to increased NK-cell lytic activity in AML patients. These data suggest that modulation of IL-15 levels in AML could be therapeutically beneficial as IL-15 enhances NK-cell recovery following intensive chemotherapy and increases NK-cell anti-tumor activity.

3076 Background: NK cell cytotoxicity is tightly controlled through a balance of signals from the functionally opposing activating and inhibitory receptors found on each cell. Interleukin-15 (IL-15) has a major role in NK cell homeostasis. IL-15 induces the differentiation of NK cells from hematopoietic progenitors, stimulates the expansion of peripheral NK cells and supports their survival. Modulation of the relative frequency and intensity of expression of the NK cell receptors by IL-15 may increase NK mediated cytotoxicity in cancer patients. Methods: We investigated the receptor repertoire and measured NK cell activity in the peripheral blood of 21 patients with newly diagnosed AML prior to any treatment and 15 normal donors. Ex-vivo effects of IL-15 on the NK cell repertoire and NK cell cytotoxicity were investigated. Results: The expression of the activating natural cytotoxicity (NCR) receptors NKp30 and NKp46 and the C-type lectin receptors NKG2D and NKG2C were significantly decreased in the AML patients compared to the NK cells of healthy donors (p<0.0001–0.03). Furthermore, NK cytotoxicity was significantly lower (p<0.0003) in the AML patients at diagnosis compared to that of healthy donors. When NK cells obtained from AML patients were cultured with IL-15, expression of the activating receptors was significantly increased compared to pre-culture levels: NKp30, 84 vs 20% p<0.001; NKp44, 71 vs 4% p<0.0001; NKp46, 83 vs 32% p<0.0002; NKG2D 87 vs 43% p<0.01; NKG2C, 58 vs 18% p<0.005. Concomitantly, cytotoxic activity of NK cells sorted from AML patients increased following IL-15 stimulation (790 vs 2211 LU, p<0.05). This IL-15 induced increase in the activity was blocked by neutralizing antibodies against the NK cell activating receptors. Conclusions: We determined that IL-15, a homeostatic NK cell cytokine, can upregulate the expression of the NK activating receptors and concomitantly increase the NK lytic activity in patients with AML. These data support the use of IL-15 as a platform for NK- based therapies for AML patients. No significant financial relationships to disclose.

Regulatory CD4+CD25+ T cells (T reg) are critical regulators of immune tolerance. Increasing evidence supports the existence of elevated numbers of regulatory T cells in cancer patients. Although the increase of T cells seems to be a characteristic feature in most tumors the functional role of Treg, especially in patients with hematologic malignancies, has been less well defined. Mutlicolor flow cytomerty was used to investigated the frequency and phenotype of CD4+ CD25high T cells in the peripheral blood of thirty seven newly diagnosed acute myeloid leukemia (AML) patients (prior to any treatment) and thirty one healthy donors. The suppressive function of Treg was evaluated using CFSE-labeled fresh autologous CD4+CD25− T cells activated with an anti-CD3 antibody as responders. The percentage of circulating CD4+ CD25high Treg was higher (p < 0.0001) in the AML patients (2.9 ± 0.3%, range 0.1–7%) compared to healthy donors (0.4 ± 0.02%, range 0.1–1%). Percentages of T reg expressing Foxp3, CTLA-4, CD45 RO, Fas ligand (CD95) and GITR were significantly elevated in the circulation of AML patients compared to healthy donors: Foxp3 60vs32% p<0.001, CTLA-4 47vs21% p<0.01, CD45 RO 81vs53% p<0.002, Fas ligand 23vs4% p<0.001, GITR 65vs25% p<0.001. Suppression mediated by T reg co-incubated with proliferating autologous responders was also significantly higher (p<0.001) in AML than that mediated by control T reg (75 ± 6% vs 12% ± 4%). These results indicate that T reg accumulate in the periphery of patients with AML and mediate vigorous suppression. Modulation of the Treg suppressive activity, especially during the post-induction period, in AML patients may have therapeutic implications.

Natural killer (NK) cells lyse malignant cells without prior antigen-specific priming and play a critical role in the innate immune response. A balance of signals from activating and inhibiting receptors expressed on each NK cell controls its activity. The growth, differentiation and survival of NK cells have been found to be dependent on interleukin-15 (IL-15). Using multicolor flow cytometry we investigated the receptor repertoire and also measured the NK cell activity in twenty three patients with newly diagnosed acute myeloid leukemia (AML) prior to any treatment. Further, we investigated the ex-vivo effect of IL-15 on the NK cell repertoire and NK cell cytotoxicity. The percentage of circulating NK cells was lower (p<0.0001) in the AML patients (6%± 0.7, range 1–17%) compared to the NK cells of healthy donors (12%± 1, range 9–17%). The expression of the activating natural cytotoxicity (NCR) receptors NKp30 and NKp46 and the C-type lectin receptors NKG2D and NKG2C was significantly decreased in the AML patients compared to the NK cells of healthy donors: NKp30 24 vs 51% p<0.0001, NKp46 32 vs 73% p<0.0001, NKG2D 43 vs 83% p<0.0001, NKG2C 17 vs 28% p<0.03. In addition, the receptor expression (mean fluorescence intensity, MFI) was also significantly lower in AML patients compared to healthy donors. No significant differences in the expression of the NCR NKp44 and the NK- cell inhibitory receptors were observed. Furthermore, the NK cytotoxicity in the AML patients at diagnosis was significantly lower (p<0.0003) compared to the NK cytotoxicity of healthy donors (4 vs 75 LU). When NK cells obtained from AML patients were cultured with IL-15, significant increases in the expression of the NK- cell activating receptors (Table 1) were observed. The upregulation of the activating receptors was associated with a concomitant significant increase (p<0.001) of the NK cell cytotoxicity (4 vs 70 LU). The data suggest that IL-15, a homeostatic NK cell cytokine, can upregulate the expression of activating receptors and concomitantly increase the NK lytic activity. The use of IL-15 as a platform for NK- based therapies for AML patients should be considered in the future.

7054 Background: Regulatory CD4+CD25+ T cells (T reg) are critical regulators of immune tolerance. However, the functional role of T reg in human tumor immunity has been less well studied. The frequency of circulating Treg is increased in patients with solid malignancies. We evaluated the frequency, phenotype and suppressive function of T reg in patients with acute myeloid leukemia (AML). Methods: The frequency and phenotype of CD4+ CD25high T cells were investigated in the peripheral blood of fifteen newly diagnosed AML patients prior to any treatment and fifteen healthy donors by multiparameter flow cytometry. The suppressive function of Treg was evaluated using CFSE-labeled fresh autologous CD4+CD25- T cells activated with an anti-CD3 antibody. Results: The percentage of circulating CD4+ CD25high Treg was higher (p <0.001) in the AML patients (5.2 ± 1.3%, range 0.4 −7%) compared to healthy donors (1.1 ± 0.2%, range 0.8–1.5%). T reg expressing Foxp3, CTLA-4, CD45 RO, CCR4 and Fas receptor (CD95) were significantly elevated in the circulation of AML patients, but GITR expression on Treg was low. Suppression mediated by T reg co-incubated with proliferating autologous responders was also significantly higher (p<0.001) in AML than that mediated by control T reg (75 ± 6% vs 12%± 4%). Conclusions: These results indicate that T reg accumulate in the periphery of patients with AML and have vigorous suppressive functions. This high suppressive activity may impair the host anti-tumor responses and promote leukemogenesis. No significant financial relationships to disclose.

The most effective reinduction regimen for acute myeloid leukemia (AML) patients who do not achieve complete remission (CR) after one cycle of cytarabine combined with an anthracycline is not well established. In an effort to search for new synergistic and non-cross resistant antileukemic regimens different chemotherapeutic combinations have been investigated in refractory AML patients. Multiple regimens including high dose cytarabine, anthracyclines, fludarabine and etoposide have been used with CR rates up to 40%. Mitoxantrone and etoposide have activity in AML as induction agents but their role in reinduction in patients not responding to first line therapy has not been fully established. In the current retrospective study we evaluated the efficacy and toxicity of mitoxantrone and etoposide in AML patients treated at our institution who did not respond to first induction therapy with cytarabine and an anthracycline. A total of fifty seven AML patients were treated with mitoxantrone and etoposide (mean age 55 years, range 18–75 years). Twenty four patients were treated with mitoxantrone 10 mg/m2/d and etoposide 100 mg/m2/d both administered intravenously, days 1 to 5 (regimen 5+5) and thirty three patients were treated with mitoxantrone 10 mg/m2/d administered intravenously days 1 to 3 and etoposide 100 mg/m2/d administered intravenously, days 1 to 5 (regimen 3+5). Twenty six of fifty seven patients (46%) achieved CR. CR was achieved in 38% of patients (9/24) treated with the 5+5 regimen and 52% of patients (17/33) treated with the 3+5 regimen. Mean blast percentage before treatment with mitoxantrone and etoposide was 25% in patients who achieved CR vs 40% in patients who did not achieve CR (p < 0.03). Grade 3/4 hepatic toxicities were seen in 5% (3/57) of patients and there were no grade 3 or 4 renal toxicities. The median duration of neutropenia in patients achieving CR was 29 days after reinduction. 10% (6/57) of the patients died from infectious complications. Cytogenetic analyses were performed prior to first-line therapy in all patients. Patients with favorable cytogenetics treated with etoposide and mitoxantorne had 100% CR (3/3), patients with standard cytogenetics had 58% CR (19/33) and patients with unfavorable cytogenetics had 19% CR (4/21). Overall CR was achieved in 61% (22/36) of patients with favorable and standard cytogenetics. Our data suggest that the combination of etoposide and mitoxantorne is an active and well tolerated regimen, especially in patients with favorable and standard cytogenetics, and warrants further studies in prospective trials.