Dendritic cell (DC) vaccines can induce antitumor immune responses in patients with malignant diseases, while the most suitable DC culture conditions have not been established yet. In this study we ...compared monocyte derived human DC from conventional cultures containing GM-CSF and IL-4/TNF-alpha (IL-4/TNF-DC) with DC generated by the novel protocol using GM-CSF and IFN-alpha (IFN-DC).
To characterise the molecular differences of both DC preparations, gene expression profiling was performed using Affymetrix microarrays. The data were conformed on a protein level by immunophenotyping, and functional tests for T cell stimulation, migration and cytolytic activity were performed.
Both methods resulted in CD11c+ CD86+ HLA-DR+ cells with a typical DC morphology that could efficiently stimulate T cells. But gene expression profiling revealed two distinct DC populations. Whereas IL-4/TNF-DC showed a higher expression of genes envolved in phagocytosis IFN-DC had higher RNA levels for markers of DC maturity and migration to the lymph nodes like DCLAMP, CCR7 and CD49d. This different orientation of both DC populations was confined by a 2.3 fold greater migration in transwell experiments (p = 0.01). Most interestingly, IFN-DC also showed higher RNA levels for markers of NK cells such as TRAIL, granzymes, KLRs and other NK cell receptors. On a protein level, intracytoplasmatic TRAIL and granzyme B were observed in 90% of IFN-DC. This translated into a cytolytic activity against K562 cells with a median specific lysis of 26% at high effector cell numbers as determined by propidium iodide uptake, whereas IL-4/TNF-DC did not induce any tumor cell lysis (p = 0.006). Thus, IFN-DC combined characteristics of mature DC and natural killer cells.
Our results suggest that IFN-DC not only stimulate adaptive but also mediate innate antitumor immune responses. Therefore, IFN-DC should be evaluated in clinical vaccination trials. In particular, this could be relevant for patients with diseases responsive to a treatment with IFN-alpha such as Non-Hodgkin lymphoma or chronic myeloid leukemia.
Abstract We report a case of a patient with multiple myeloma and engraftment failure after high-dose therapy with autologous stem cell transplantation. After rescue treatment with G-CSF and back-up ...reinfusion of autologous stem cells failed, allogeneic umbilical cord blood transplantation resulted in neutrophil engraftment on day +16 and a 57 months lasting complete remission. This case report shows that umbilical cord blood transplantation is a rescue option after engraftment failure of autologous transplantation, which is available for 99% of patients due to the less stringent HLA matching criteria. Moreover, the prompt availability allows transplantation to be performed at an optimal time.
Background: Using real-time quantitative (RQ) PCR we recently (Haematologica 89, 2004) identified a prognostic cut-off level of residual clonotypic cells in the bone marrow of patients with multiple ...myeloma before high-dose therapy (HDT) and autologous peripheral blood stem cell transplantation (PBSCT). In this study we validate this report with a larger number of patients.
Patients and Methods: Bone marrow samples of 68 patients with stage II/III multiple myeloma and heavy chain disease were obtained at the time of diagnosis and after induction therapy and stem cell collection but before single HDT and autologous PBSCT. Sequencing of the patient specific immunoglobulin heavy chain (IgH) locus was successful in 51 patients (75%). For 49 patients (72%) RQ-PCR using allele-specific oligonucleotide (ASO) Taqman probes together with LightCycler technology could be established with a sensitivity of 10−4 to 10−6 and linear amplification conditions. The proportion of clonotypic cells was assessed as IgH / 2 beta-actin ratio in percent. Patients were divided in two prognostic groups by a threshold level of 0.03% clonotypic cells.
Results: The median level of residual tumor cells in bone marrow of all patients at the time before transplantation was 0.05% (range: 0–21%). Time to progression (TTP) from the time of diagnosis of patients in the ¨good¨ prognostic group (n = 21) was 51 months and significantly (p = 0.002) longer in comparison to 20 months of patients with a pre-transplantation minimal residual disease level of more than 0.03% in BM (n = 28). Overall survival (OS) of patients within the ¨good¨ prognostic group was also significantly prolonged (median OS: not reached versus 46 months, p = 0.03). Univariate analysis also revealed kind of maintenance / consolidation therapy (thalidomide, interferon, reduced intensity conditioning (RIC) allogeneic transplant) and cytogenetic banding analysis as prognostic markers for TTP. For OS kind of maintenance therapy, cytogenetic abnormalities, ISS stage, CRP and LDH levels were of prognostic relevance. In multivariat analysis grouping by pre-transplantation MRD level was an independent prognostic factor for either TTP and OS.
Conclusion: Quantitative molecular assessment of pre-transplantation tumor level in the bone marrow is an independent prognostic parameter for TTP and OS of patients with multiple myeloma. This finding has two controversial implications. One conclusion could be, that induction therapy should be continued and intensified e.g. with novel agents until a low MRD level is achieved. An alternative conclusion is, that a low tumor burden after induction therapy may be a surrogate parameter for chemosensitive disease, which makes patients more susceptible for high-dose chemotherapy. Therefore, further MRD studies are needed to answer this important question.
Abstract 2057
Poster Board II-34
Patients with acute myeloid leukemia (AML) and activating mutations in the Fms-like tyrosine-3 (FLT3) gene have an abysmal prognosis. Together with other groups we ...have recently demonstrated the clinical activity of the multikinase and FLT3 inhibitor sorafenib in patients with FLT3+ AML (Safaian et al., 2008; Zhang et al., 2008; Metzelder et al., 2009). We here present clinical results of 8 AML FLT3+ patients treated with sorafenib either prior or after allogeneic stem cell transplantation (allo-SCT) on an off-label basis.
Between February 2007 to August 2009 eight patients with AML (7 female, 1 male, median age: 47 years, range 23-63 years) were treated with sorafenib 800 mg daily (dose range 400-800 mg daily) for a median duration of 37 days (range 5-225 days). Six patients had an internal tandem duplication mutation (ITD), while 2 patients carried a tyrosine kinase domain (TKD) mutation. One patient received sorafenib at diagnosis before remission induction while all other patients had relapsed and/or refractory disease. Response and toxicity were evaluated regularly and defined according to established criteria.
Two of four patients who received sorafenib for refractory relapse after allo-SCT (median time to relapse 78 days, range 59-84 days) achieved complete remission (CR) (1 CR, 1 complete molecular remission (CMR) with disappearance of extramedullary chloromas) and survived 164 and 594 days, respectively. One of these patients died after another systemic relapse, while the other died as result of a CNS-chloroma being still in CMR in bone marrow (BM). In the 2 other patients sorafenib induced a hematological response (HR) and these patients survived 188 and 329 days before they died of progressive disease.
Of the 4 patients treated prior allo-SCT, 2 had relapsed during consolidation after a previous CR, 1 had refractory disease and 1 was treated at diagnosis. Both patients with relapse showed response to sorafenib treatment thereby permitting allo-SCT. While one achieved HR, the other had regression of multiple isolated cutaneous relapse manifestations. Both patients are still alive at day +81 and day +16 in CMR and CR, respectively. The patient, who was primary refractory to double induction and high-dose cytarabine had a reduction of BM-blasts. She discontinued sorafenib because of neurotoxicity after 13 days. This patient reached a CR after allo-SCT, but died on day + 379 of another relapse.
At the time of AML diagnosis the fourth patients had a WBC of 377.000/ul. Despite treatment with hydroxyurea, cytarabine and leukapheresis WBC could not be lowered <100.000/ul within 5 days and the patient developed pulmonary leukostasis syndrome. At this point of time FLT3 TKD mutation was detected and sorafenib was started promptly. Within the next 5 days WBC (peripheral blasts %) declined from 119.700/μl (98%) to 5.300/μl (28%) without tumor lysis syndrome facilitating induction therapy with cytarabine, daunorubicin and etoposide. Sorafenib therapy was continued in parallel and led to a CMR without increased toxicity.
In general, sorafenib treatment was well tolerated. Besides neurotoxicity in one patient extrahematological side effects were almost limited to transient dermatological symptoms in two patients, which resolved after discontinuitation of sorafenib. Four Patients developed neutropenia grade IV and thrombopenia grade IV, which was not exclusively attributable to sorafenib, but also to the underlying AML.
Our results add to the growing evidence that sorafenib is highly active in patients with FLT3+ AML. In view of the clinical course of our patients we suggest that sorafenib can achieve temporary disease control, but should be integrated into induction and consolidation regimens to achieve curative treatment. Recent data on synergistic effects between sorafenib and cytarabine and the CXCR4 inhibitor AMD3100 suggest these combinations for new clinical trials.
Off Label Use: individual treatment approach of patients with refractory FLT3+ AML with multikinase inhibitor sorafenib, which is approved by EMEA + FDA for renal cell carcinoma.
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