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In recent years there has been a great improvement in molecular characterization of acute myeloid leukemia (AML) allowing the stratification of patients in different rate of risk. Patients with FLT3 mutated AML have poor prognosis because of resistance to induction chemotherapy or early relapse. Several first and second generation molecules, able to inhibit FLT3 signaling have been developed and many single agent or combination studies are ongoing. Of these, quizartinib seems to have the best clinical activity. Unfortunately, resistance to FLT3 inhibitors has been observed and many scientists are currently investigating new strategy to restore sensitivity to FLT3 inhibitors.

Background Although imatinib is the standard treatment for chronic myeloid leukaemia, not all patients reach complete cytogenetic remission (CCR) and most maintain detectable disease at the molecular level. We investigated whether a vaccine targeting the BCR-ABL-derived p210 fusion protein was an active and specific immunotherapy.Methods We recruited 16 patients who had chronic myeloid leukaemia (with the b3a2 fusion point of p210), stable residual disease, a minimum treatment of 12 months of imatinib or 24 months of interferon alfa, and no further reduction of residual disease for at least 6 months preceding enrolment. They were given six vaccinations with a peptide vaccine derived from the sequence p210-b3a2 plus molgramostim and QS-21 as adjuvants (CMLVAX100) before assessment of immunological and disease response, which included detecting amounts of b3a2 transcripts by standardised quantitative real-time reverse-transcriptase PCR.Results Of ten patients on imatinib, nine started CMLVAX100 having had a median of 10 months’ stable cytogenetic disease (median 10% Philadelphia-chromosome-positive metaphases), whereas one started in stable CCR. All patients’ cytogenetic responses improved after six vaccinations, with five reaching CCR. Notably, three of these five patients also had undetectable amounts of b3a2 transcript (BCR-ABL:β2 microglobulin ratio <0·00001). Six patients on interferon alfa treatment with a median of 17 months’ stable residual disease (median 13% Philadelphia-chromosome-positive cells) were also vaccinated. All but one had improved cytogenetic responses, and two reached CCR. Overall, we recorded peptide-specific delayed-type hypersensitivity (in 11 of 16 patients), CD4 cell proliferation (13 of 14 assessed), and interferon γ production (five of five assessed).Interpretation Addition of CMLVAX100 to conventional treatment in patients with chronic myeloid leukaemia might favour further reduction of residual disease and increase the number of patients reaching a molecular response.

Chronic myelogenous leukemia (CML) presents a unique opportunity to develop therapeutic strategies using vaccination against a truly tumor-specific antigen that is also the oncogenic protein required for neoplasia. CML is characterized by the t(9;22) that results in the bcr-abl fusion oncogene and in the expression of a chimeric protein product p210. Previously we have shown that peptides derived from amino acid sequences crossing the b3a2 fusion breakpoint in p210 elicit class I restricted cytotoxic T lymphocytes and class II responses, respectively, in vitro. Such sequences may thus comprise absolutely tumor-specific antigens in a peptide-based vaccine. We evaluated the safety and immunogenicity of a multidose, bcr-abl breakpoint peptide vaccine in 12 adults with chronic-phase CML. Cohorts of 3 patients each received either 50 μg, 150 μg, 500 μg, or 1500 μg total peptide mixed with 100 μg QS-21 as an immunological adjuvant. Delayed-type hypersensitivity (DTH), humoral responses, and unprimed ex vivo autologous proliferation (3H-thymidine incorporation) and cytotoxicity (chromium-51 release) responses were measured. All 68 vaccinations were well tolerated without significant adverse effects. In 3 of the 6 patients treated at the 2 highest dose levels of vaccine, peptide-specific, T-cell proliferative responses (n = 3) and/or DTH responses (n = 2) were generated that lasted up to 5 months after vaccination. Cytotoxic T lymphocytes have not been identified. In conclusion, a tumor-specific, bcr-abl derived peptide vaccine can be safely administered to patients with chronic-phase CML and can elicit a bcr-abl peptide-specific immune response despite the presence of active disease in these patients and approximately 1012 leukemia cells.

Chronic myelogenous leukemia (CML) presents a unique opportunity to develop therapeutic strategies using vaccination against a truly tumor-specific antigen that is also the oncogenic protein required for neoplasia. CML is characterized by the t(9;22) that results in the bcr-abl fusion oncogene and in the expression of a chimeric protein product p210. Previously we have shown that peptides derived from amino acid sequences crossing the b3a2 fusion breakpoint in p210 elicit class I restricted cytotoxic T lymphocytes and class II responses, respectively, in vitro. Such sequences may thus comprise absolutely tumor-specific antigens in a peptide-based vaccine. We evaluated the safety and immunogenicity of a multidose, bcr-abl breakpoint peptide vaccine in 12 adults with chronic-phase CML. Cohorts of 3 patients each received either 50 μg, 150 μg, 500 μg, or 1500 μg total peptide mixed with 100 μg QS-21 as an immunological adjuvant. Delayed-type hypersensitivity (DTH), humoral responses, and unprimed ex vivo autologous proliferation (3H-thymidine incorporation) and cytotoxicity (chromium-51 release) responses were measured. All 68 vaccinations were well tolerated without significant adverse effects. In 3 of the 6 patients treated at the 2 highest dose levels of vaccine, peptide-specific, T-cell proliferative responses (n = 3) and/or DTH responses (n = 2) were generated that lasted up to 5 months after vaccination. Cytotoxic T lymphocytes have not been identified. In conclusion, a tumor-specific, bcr-abl derived peptide vaccine can be safely administered to patients with chronic-phase CML and can elicit a bcr-abl peptide-specific immune response despite the presence of active disease in these patients and approximately 1012leukemia cells.

Chronic myelogenous leukemia (CML) cells are characterized by a t(9;22) translocation, which can encode one of two chimeric P210 bcr-abl fusion proteins, comprising products of either the b2a2 or the b3a2 exon junction. The junctional sequences represent potentially immunogenic tumor-specific antigens. Despite their intracellular location, the fusion proteins might be recognized immunologically by T lymphocytes if peptides, derived from these unique sequences, are capable of presentation by the major histocompatibility complex molecules. We previously found that four peptides, 9 to 11 amino acids long, spanning the b3a2 CML breakpoint bind with high or intermediate affinity to purified HLA class I molecules A3, A11, B8, or both A3 and A11. We tested the ability of these peptides to elicit specific class I restricted cytotoxic T lymphocytes (CTLs) in vitro in HLA-matched healthy donors. In addition, a longer b3a2 CML-breakpoint-derived peptide, 25 aminoacids in length (b3a2–25), was studied for its ability to induce peptide-specific, class II-mediated, T-cell proliferation. In four of four HLA-A3 donors tested, CML-A3/A11-peptide specific CTLs were induced that killed an allogeneic HLA-A3-matched peptide pulsed leukemia cell line. In two of three HLA-A3 donors, the CML-A3/A11 peptide was able to induce killing of autologous and allogeneic HLA- matched peptide-pulsed peripheral blood mononuclear cells (PBMC). CML- A3 peptide induced peptide specific CTLs in one of the four HLA A3 donors tested. No killing was observed in two HLA-B8 and two HLA-A11 donors. PBMC from seven donors were also tested for anti b3a2–25 peptide proliferation in a thymidine incorporation assay. Specific proliferation was detected in three donors, all of the HLA-DR11 haplotype. These data represent the first evidence of a cytolytic human immune response against CML bcr-abl oncogene-derived peptides and provide a rationale for developing peptide-based vaccines for this disease.

Many human leukemias are characterized by chromosomal translocations yielding hybrid RNAs capable of encoding fusion chimeric proteins. The unique amino acid sequences found in these oncogenic fusion proteins represent true tumor-specific antigens that are potentially immunogenic. Although these leukemia-specific fusion proteins have an intracellular location, they might be recognized immunologically by T lymphocytes if peptides derived from the unique sequences are capable of presentation by the major histocompatibility complex (MHC) molecules on leukemic cells. The ability of a series of synthetic peptides corresponding to the junctional sequences of chronic myelogenous leukemia (CML)-derived bcr-abl and acute promyelocytic leukemia (APL)-derived PML-RAR alpha fusion proteins to bind to purified class I molecules was studied. A series of 152 peptides 8, 9, 10, and 11 amino acids in length, spanning the b3a2 and b2a2 breakpoints for CML and PML-RAR alpha A and B breakpoints for APL were analyzed for HLA A1, A2.1, A3.2, A11, A24, B7, B8, and B27 binding motifs. Twenty-one CML peptides and 4 APL peptides were predicted to be potential HLA class I binders. The peptides were tested for binding to appropriate purified HLA molecules in a competition radioimmunoassay. Four peptides derived from b3a2 CML breakpoint bound with high (< 50 nmol/L) or intermediate (< or = 500 nmol/L) affinity to HLA A3, A11, and B8. None of the CML b2a2 or PML-RAR alpha A or B junctional peptides showed affinity of this magnitude for the HLA class I molecules tested. This is the first evidence that tumor-specific breakpoint peptides can bind human MHC class I molecules and provides a rationale for developing a therapeutic vaccine strategy.

A prospective randomized study on aggressive non-Hodgkin's lymphomas was conducted by investigators at several Italian institutions with the intent of comparing two third-generation conceptually different regimens: the regimen containing methotrexate with leucovorin rescue, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B), a short-term continuous twelve-week therapy, and F-MACHOP (5-fluorouracil, methotrexate with leucovorin rescue, cytarabine, cyclophosphamide, doxorubicin, vincristine, and prednisone), a monthly intensive cyclic treatment combining prednisone with six active non-cross-resistant cytotoxic drugs. The goals of this study were the response rate, relapse-free survival, and incidence of hematologic and nonhematologic toxicities.Two hundred-eighty-six patients included between 15 and 60 years fulfilled the criteria for entry to the study; 140 patients were treated with MACOP-B and 146 with F-MACHOP. The minimum follow-up was 24 months. Clinical characteristics of all patients were similar and known prognostic factors were equally distributed between the two groups. Complete remission (CR) was achieved by 61% and 67% of the patients treated with MACOP-B and F-MACHOP, respectively; 4% and 6% were primarily resistant, 2% and 5%, respectively, died of causes directly related to therapy. At 50 months, 74% of all CR patients were alive without disease and there were no significant differences in relapse-free survival between the two groups: 75% in the F-MACHOP group and 73% in the MACOP-B group at 50 months. There was a higher incidence of mucositis among patients treated with MACOP-B than among those given F-MACHOP (11% vs 3.5%). Higher incidences of severe cytopenia (51% vs 21%) and of fatal sepsis (5% vs 2%) were recorded among patients treated with F-MACHOP than with MACOP-B.The third-generation regimens, F-MACHOP and MACOP-B, are as effective as other regimens. A prognostic analysis taking into account the principal covariates (age, symptoms, stage, serum lactate dehydrogenase, mediastinum involvement, bulky disease, histology, therapy, and dose intensity) was assessed for their impact on complete response rate incidence and on relapse rate from complete response by multivariate analysis. The linear logistic model showed that symptoms, advanced stage, mediastinum involvement, and bulky disease are prognostic factors that increase the risk of a lower rate of complete response. These data confirm the important role of a pretreatment selection for the poor-risk patients and, on the basis of these parameters, it will probably be possible to consider these patients for high-dose therapy with autologous bone marrow transplantation or autologous hematopoietic stem-cell support.

Thirty-seven patients with stage I-II Hodgkin's disease and massive mediastinal involvement, observed between June 1981 and November 1989, underwent combined modality treatment. This treatment included: 3 cycles of mechlorethamine, vincristine, procarbazine, and prednisone followed by mantle-field irradiation, and subsequently by 3 additional cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine. Thirty-five (95%) patients achieved complete responses and only 2 (5%) had partial responses. All the complete responders are living and relapse-free at a median follow-up of 62 months; no major toxic reactions were recorded. These data suggest, as did those of other studies, that combined modality therapy is superior to either radiotherapy or chemotherapy alone for patients in stage I-II with bulky disease, especially in the mediastinum. In fact, in these particular patients, if adequately treated with a combination of chemotherapy and radiotherapy, the role of massive mediastinal involvement as a poor prognostic factor appears to be less significant.

ABSTRACTMucormycosis is a rare complication in cancer patients. This report presents the case of a acute myeloblastic leukemia patient who developed an ascending paralysis due to disseminated mucormycosis. The presentation was unusual because the early symptoms were fever and pain, and the disease was misdiagnosed because of a concomitant infection by Enterococcus faecium.

Immunoglobulin (Ig) gene analysis delineates critical features of the clonal history of a B-cell tumor. After antigen interaction, mature B-cells undergo somatic mutation of the V-genes and isotype switch recombination, generally in the germinal center (GC). Receptor revision by secondary recombination of the V-genes with re-expression of recombination activating gene (RAG) enzymes rarely occurs at this stage. From a small series, we have reported that most hairy cell leukemias (HCL) carry mutated VH genes, with low levels of intraclonal heterogeneity, while a minor subset have unmutated VH genes. Both subsets commonly have ongoing Ig isotype switch events and express activation induced cytidine deaminase (AID). However HCL lack the GC markers CD27 and CD38, and CD23, a chemokine essential for lymph node entry. In order to probe more fully the differentiation status of the cell of origin, both VH and VL tumor-derived genes were evaluated in an expanded series of 38 HCL. From analysis of VH, the VH3 family usage was most common (24/38, 63%), with significant preference of the VH3-30 member in 10/38 cases (26%, p=0,00001), and JH4b segment utilised in 50% of cases. Most HCL (35/38) carried variable tiers of mutations (87–98.6% homology to germline), with low level of intraclonal heterogeneity also in cases with <2% deviation from germline, while 3/38 (8%) displayed completely unmutated VH genes. Analysis of VL genes provided novel insights, when 21/38 HCL were evaluated. The λ light chain was most fequently used (13/21, 62%), to indicate preferential secondary rearrangement to λ chain. All λ cases used Jγ3 segment. Nineteen of 21 cases carried mutated VL genes (94,75%–99.6%) with low levels of intraclonal heterogeneity, while 2 cases carried completely unmutated VL genes, reflecting the status of the VH gene. Strikingly, in-frame functional secondary VL chain rearrangements were observed in the tumor cells of 2 of these cases (Vκ 1 and Vκ 2 in case R1, Vκ 1 and Vκ 2 in R2). Primary and secondary rearrangements showed mutations (98.1 and 99.6% homology in R1, 97.6 and 99.6% homology in R2). In both cases, RAG1 re-induction was identified by RT-PCR and sequence verification. Both cases expressed AID transcripts and displayed intraclonal mutations in the VH and/or the VL genes. These data suggest a dynamic, on-going modification of the B-cell receptor in tumor cells, including receptor revision, which occurs most likely in response to antigenic stimuli. N-glycosylation sites, commonly introduced in the V regions of tumors of the GC by somatic mutation, were not observed in the VH or in the VL functional genes, to support the concept that tumor events occur outside the GC. These data confirm heterogeneity in the cell of origin in terms of mutational status, with a minor subset with unmutated V-genes. Restricted V-gene segment usage, low levels of ongoing mutations with AID activated, and the new observation of receptor revision with re-expression of RAG enzymes indicate that selection by antigen could be a promoting factor in HCL development. Lack of novel glycosylation sites is in favour of interaction with antigenic stimuli occurring at extrafollicular sites.

Immunoglobulin (Ig) gene analysis delineates critical features of the clonal history of a B-cell tumor. After antigen interaction, mature B-cells undergo somatic mutation of the V-genes and isotype switch recombination, generally in the germinal center (GC). Receptor revision by secondary recombination of the V-genes with re-expression of recombination activating gene (RAG) enzymes rarely occurs at this stage. From a small series, we have reported that most hairy cell leukemias (HCL) carry mutated VHgenes, with low levels of intraclonal heterogeneity, while a minor subset have unmutated VHgenes. Both subsets commonly have ongoing Ig isotype switch events and express activation induced cytidine deaminase (AID). However HCL lack the GC markers CD27 and CD38, and CD23, a chemokine essential for lymph node entry.