First-hit SETBP1 mutations cause a myeloproliferative disorder with bone marrow fibrosis.

ABSTRACT: SETBP1 mutations are found in various clonal myeloid disorders. However, it is unclear whether they can initiate leukemia, because SETBP1 mutations typically appear as later events during oncogenesis. To answer this question, we generated a mouse model expressing mutated SETBP1 in hematopoietic tissue: this model showed profound alterations in the differentiation program of hematopoietic progenitors and developed a myeloid neoplasm with megakaryocytic dysplasia, splenomegaly, and bone marrow fibrosis, prompting us to investigate SETBP1 mutations in a cohort of 36 triple-negative primary myelofibrosis (TN-PMF) cases. We identified 2 distinct subgroups, one carrying SETBP1 mutations and the other completely devoid of somatic variants. Clinically, a striking difference in disease aggressiveness was noted, with patients with SETBP1 mutation showing a much worse clinical course. In contrast to myelodysplastic/myeloproliferative neoplasms, in which SETBP1 mutations are mostly found as a late clonal event, single-cell clonal hierarchy reconstruction in 3 patients with TN-PMF from our cohort revealed SETBP1 to be a very early event, suggesting that the phenotype of the different SETBP1+ disorders may be shaped by the opposite hierarchy of the same clonal SETBP1 variants.

ALK peptide vaccination restores the immunogenicity of ALK-rearranged non-small cell lung cancer.

Anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) is treated with ALK tyrosine kinase inhibitors (TKIs), but the lack of activity of immune checkpoint inhibitors (ICIs) is poorly understood. Here, we identified immunogenic ALK peptides to show that ICIs induced rejection of ALK+ tumors in the flank but not in the lung. A single-peptide vaccination restored priming of ALK-specific CD8+ T cells, eradicated lung tumors in combination with ALK TKIs and prevented metastatic dissemination of tumors to the brain. The poor response of ALK+ NSCLC to ICIs was due to ineffective CD8+ T cell priming against ALK antigens and is circumvented through specific vaccination. Finally, we identified human ALK peptides displayed by HLA-A*02:01 and HLA-B*07:02 molecules. These peptides were immunogenic in HLA-transgenic mice and were recognized by CD8+ T cells from individuals with NSCLC, paving the way for the development of a clinical vaccine to treat ALK+ NSCLC.

Targeting CCR7-PI3Kγ overcomes resistance to tyrosine kinase inhibitors in ALK-rearranged lymphoma.

Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) show potent efficacy in several ALK-driven tumors, but the development of resistance limits their long-term clinical impact. Although resistance mechanisms have been studied extensively in ALK-driven non-small cell lung cancer, they are poorly understood in ALK-driven anaplastic large cell lymphoma (ALCL). Here, we identify a survival pathway supported by the tumor microenvironment that activates phosphatidylinositol 3-kinase γ (PI3K-γ) signaling through the C-C motif chemokine receptor 7 (CCR7). We found increased PI3K signaling in patients and ALCL cell lines resistant to ALK TKIs. PI3Kγ expression was predictive of a lack of response to ALK TKI in patients with ALCL. Expression of CCR7, PI3Kγ, and PI3Kδ were up-regulated during ALK or STAT3 inhibition or degradation and a constitutively active PI3Kγ isoform cooperated with oncogenic ALK to accelerate lymphomagenesis in mice. In a three-dimensional microfluidic chip, endothelial cells that produce the CCR7 ligands CCL19/CCL21 protected ALCL cells from apoptosis induced by crizotinib. The PI3Kγ/δ inhibitor duvelisib potentiated crizotinib activity against ALCL lines and patient-derived xenografts. Furthermore, genetic deletion of CCR7 blocked the central nervous system dissemination and perivascular growth of ALCL in mice treated with crizotinib. Thus, blockade of PI3Kγ or CCR7 signaling together with ALK TKI treatment reduces primary resistance and the survival of persister lymphoma cells in ALCL.

Treatment in patients with acute myeloid leukemia/high-risk myelodysplastic syndrome with hypomethylating agents: Day-hospital management compared to home care setting.

OBJECTIVES: Aim of the study was to evaluate the role of a Domiciliary Hematologic Care Unit (DHCU) compared to standard DH setting in the active frontline treatment with hypomethylating agents (HMAs) +/- venetoclax of frail patients with acute myelogenous leukemia/high-risk myelodysplastic syndromes (AML/HR-MDS). METHODS: All patients with newly diagnosed AML/HR-MDS unfit for intensive care and treated frontline with HMAs from January 2010 to April 2021 were retrospectively included. RESULTS: Among 112 patients (62 AML/50 HR-MDS), 69 (61.6%) were treated in a standard DH setting and 43 (38.4%) were followed by DHCU, allocated to DH or DHCU by responsible physician. Overall response rate was 29/69 (42.0%) in DH versus 19/43 (44.1%) in DHCU (p = .797). Median response duration was 8.7 months (95%CI 7.0-10.3) in DH versus 13.0 months (95%CI 8.3-17.6) in DHCU (p = .460). Infections were also equally reported. Median overall survival of patients treated in DH was 13.7 months (95%CI 9.9-17.4) compared to 13.0 months (95%CI 6.7-19.3) of patients managed by DHCU (p = .753). CONCLUSIONS: Home care management of HMA is feasible and effective, with results similar to standard DH setting: this approach is thus adequate to offer active therapies in frail patients with AML/HR-MDS considered up to now ineligible.

Validation of a new NGS-based myeloid panel in acute myeloid leukemia: A single-center experience.

Acute myeloid leukemia (AML) identifies a heterogeneous group of clonal disorders, both clinically and genetically. A large number of mutations have been described in AML, although only a few are currently employed in clinical practice. Next generation sequencing (NGS) allows for better understanding of the complex genetic background in AML and may direct individualized therapies. In this study, we aim to identify molecular aberrations that are not routinely investigated in AML using an NGS-based panel encompassing 101 genes and to evaluate how their oncogenic potential correlates with survival. Forty consecutive patients with newly diagnosed AML were enrolled between January 2018 and April 2020. We performed targeted NGS and detected 96 mutations in 36 patients (90%), while 14 fusion genes were detected in 13 patients (32%). Each mutation was weighed using OncoScore, a text-mining tool ranking genes according to their oncogenic potential. An OncoScore ≥ 100 was associated with shorter PFS among our patients (p = 0.05). In 11 patients with no available MRD markers at diagnosis, we were able to perform NGS-based MRD monitoring using targeted deep sequencing. Overall, our study shows that NGS is a powerful tool in AML and should be employed both in routine diagnostic workup and follow up.

Synergistic Drug Combinations Prevent Resistance in ALK+ Anaplastic Large Cell Lymphoma.

Anaplastic lymphoma kinase-positive (ALK+) anaplastic large-cell lymphoma (ALCL) is a subtype of non-Hodgkin lymphoma characterized by expression of the oncogenic NPM/ALK fusion protein. When resistant or relapsed to front-line chemotherapy, ALK+ ALCL prognosis is very poor. In these patients, the ALK inhibitor crizotinib achieves high response rates, however 30-40% of them develop further resistance to crizotinib monotherapy, indicating that new therapeutic approaches are needed in this population. We here investigated the efficacy of upfront rational drug combinations to prevent the rise of resistant ALCL, in vitro and in vivo. Different combinations of crizotinib with CHOP chemotherapy, decitabine and trametinib, or with second-generation ALK inhibitors, were investigated. We found that in most cases combined treatments completely suppressed the emergence of resistant cells and were more effective than single drugs in the long-term control of lymphoma cells expansion, by inducing deeper inhibition of oncogenic signaling and higher rates of apoptosis. Combinations showed strong synergism in different ALK-dependent cell lines and better tumor growth inhibition in mice. We propose that drug combinations that include an ALK inhibitor should be considered for first-line treatments in ALK+ ALCL.

Integrated Genomic, Functional, and Prognostic Characterization of Atypical Chronic Myeloid Leukemia.

Atypical chronic myeloid leukemia (aCML) is a BCR-ABL1-negative clonal disorder, which belongs to the myelodysplastic/myeloproliferative group. This disease is characterized by recurrent somatic mutations in SETBP1, ASXL1 and ETNK1 genes, as well as high genetic heterogeneity, thus posing a great therapeutic challenge. To provide a comprehensive genomic characterization of aCML we applied a high-throughput sequencing strategy to 43 aCML samples, including both whole-exome and RNA-sequencing data. Our dataset identifies ASXL1, SETBP1, and ETNK1 as the most frequently mutated genes with a total of 43.2%, 29.7 and 16.2%, respectively. We characterized the clonal architecture of 7 aCML patients by means of colony assays and targeted resequencing. The results indicate that ETNK1 variants occur early in the clonal evolution history of aCML, while SETBP1 mutations often represent a late event. The presence of actionable mutations conferred both ex vivo and in vivo sensitivity to specific inhibitors with evidence of strong in vitro synergism in case of multiple targeting. In one patient, a clinical response was obtained. Stratification based on RNA-sequencing identified two different populations in terms of overall survival, and differential gene expression analysis identified 38 significantly overexpressed genes in the worse outcome group. Three genes correctly classified patients for overall survival.

Wiskott-Aldrich syndrome protein (WASP) is a tumor suppressor in T cell lymphoma.

In T lymphocytes, the Wiskott-Aldrich Syndrome protein (WASP) and WASP-interacting-protein (WIP) regulate T cell antigen receptor (TCR) signaling, but their role in lymphoma is largely unknown. Here we show that the expression of WASP and WIP is frequently low or absent in anaplastic large cell lymphoma (ALCL) compared to other T cell lymphomas. In anaplastic lymphoma kinase-positive (ALK+) ALCL, WASP and WIP expression is regulated by ALK oncogenic activity via its downstream mediators STAT3 and C/EBP-ß. ALK+ lymphomas were accelerated in WASP- and WIP-deficient mice. In the absence of WASP, active GTP-bound CDC42 was increased and the genetic deletion of one CDC42 allele was sufficient to impair lymphoma growth. WASP-deficient lymphoma showed increased mitogen-activated protein kinase (MAPK) pathway activation that could be exploited as a therapeutic vulnerability. Our findings demonstrate that WASP and WIP are tumor suppressors in T cell lymphoma and suggest that MAP-kinase kinase (MEK) inhibitors combined with ALK inhibitors could achieve a more potent therapeutic effect in ALK+ ALCL.

Lorlatinib Treatment Elicits Multiple On- and Off-Target Mechanisms of Resistance in ALK-Driven Cancer.

: Targeted therapy changed the standard of care in ALK-dependent tumors. However, resistance remains a major challenge. Lorlatinib is a third-generation ALK inhibitor that inhibits most ALK mutants resistant to current ALK inhibitors. In this study, we utilize lorlatinib-resistant anaplastic large cell lymphoma (ALCL), non-small cell lung cancer (NSCLC), and neuroblastoma cell lines in vitro and in vivo to investigate the acquisition of resistance and its underlying mechanisms. ALCL cells acquired compound ALK mutations G1202R/G1269A and C1156F/L1198F in vitro at high drug concentrations. ALCL xenografts selected in vivo showed recurrent N1178H (5/10 mice) and G1269A (4/10 mice) mutations. Interestingly, intracellular localization of NPM/ALKN1178H skewed toward the cytoplasm in human cells, possibly mimicking overexpression. RNA sequencing of resistant cells showed significant alteration of PI3K/AKT and RAS/MAPK pathways. Functional validation by small-molecule inhibitors confirmed the involvement of these pathways in resistance to lorlatinib. NSCLC cells exposed in vitro to lorlatinib acquired hyperactivation of EGFR, which was blocked by erlotinib to restore sensitivity to lorlatinib. In neuroblastoma, whole-exome sequencing and proteomic profiling of lorlatinib-resistant cells revealed a truncating NF1 mutation and hyperactivation of EGFR and ErbB4. These data provide an extensive characterization of resistance mechanisms that may arise in different ALK-positive cancers following lorlatinib treatment. SIGNIFICANCE: High-throughput genomic, transcriptomic, and proteomic profiling reveals various mechanisms by which multiple tumor types acquire resistance to the third-generation ALK inhibitor lorlatinib.

Epitope mapping of spontaneous autoantibodies to anaplastic lymphoma kinase (ALK) in non-small cell lung cancer.

The anaplastic lymphoma kinase (ALK) is recognized by the immune system as a tumor antigen, and preclinical evidence suggests that ALK-rearranged NSCLCs can also be successfully targeted immunologically using vaccine-based approaches. In contrast to ALK-rearranged lymphomas, the frequency and clinical significance of spontaneous ALK immune responses in patients with ALK-rearranged NSCLCs are largely unknown. We developed an enzyme-linked immunosorbent assay (ELISA) to measure anti-ALK antibody levels and mapped specific peptide epitope sequences within the ALK cytoplasmic domain in patients with non-small cell lung cancer. The ELISA method showed good correlation with ALK antibody titers measured with a standard immunocytochemical approach. Strong anti-ALK antibody responses were detected in 9 of 53 (17.0%) ALK-positive NSCLC patients and in 0 of 38 (0%) ALK-negative NSCLC patients (P<0.01), and the mean antibody levels were significantly higher in ALK-positive than in ALK-negative NSCLC patients (P=0.02). Across individual patients, autoantibodies recognized different epitopes in the ALK cytoplasmic domain, most of which clustered outside the tyrosine kinase domain. Whether the presence of high ALK autoantibody levels confers a more favorable prognosis in this patient population warrants further investigation.

Excess of NPM-ALK oncogenic signaling promotes cellular apoptosis and drug dependency.

Most of the anaplastic large-cell lymphoma (ALCL) cases carry the t(2;5; p23;q35) that produces the fusion protein NPM-ALK (nucleophosmin-anaplastic lymphoma kinase). NPM-ALK-deregulated kinase activity drives several pathways that support malignant transformation of lymphoma cells. We found that in ALK-rearranged ALCL cell lines, NPM-ALK was distributed in equal amounts between the cytoplasm and the nucleus. Only the cytoplasmic portion was catalytically active in both cell lines and primary ALCL, whereas the nuclear portion was inactive because of heterodimerization with NPM1. Thus, about 50% of the NPM-ALK is not active and sequestered as NPM-ALK/NPM1 heterodimers in the nucleus. Overexpression or relocalization of NPM-ALK to the cytoplasm by NPM genetic knockout or knockdown caused ERK1/2 (extracellular signal-regulated protein kinases 1 and 2) increased phosphorylation and cell death through the engagement of an ATM/Chk2- and γH2AX (phosphorylated H2A histone family member X)-mediated DNA-damage response. Remarkably, human NPM-ALK-amplified cell lines resistant to ALK tyrosine kinase inhibitors (TKIs) underwent apoptosis upon drug withdrawal as a consequence of ERK1/2 hyperactivation. Altogether, these findings indicate that an excess of NPM-ALK activation and signaling induces apoptosis via oncogenic stress responses. A 'drug holiday' where the ALK TKI treatment is suspended could represent a therapeutic option in cells that become resistant by NPM-ALK amplification.

Efficacy of a Cancer Vaccine against ALK-Rearranged Lung Tumors.

Non-small cell lung cancer (NSCLC) harboring chromosomal rearrangements of the anaplastic lymphoma kinase (ALK) gene is treated with ALK tyrosine kinase inhibitors (TKI), but the treatment is successful for only a limited amount of time; most patients experience a relapse due to the development of drug resistance. Here, we show that a vaccine against ALK induced a strong and specific immune response that both prophylactically and therapeutically impaired the growth of ALK-positive lung tumors in mouse models. The ALK vaccine was efficacious also in combination with ALK TKI treatment and significantly delayed tumor relapses after TKI suspension. We found that lung tumors containing ALK rearrangements induced an immunosuppressive microenvironment, regulating the expression of PD-L1 on the surface of lung tumor cells. High PD-L1 expression reduced ALK vaccine efficacy, which could be restored by administration of anti-PD-1 immunotherapy. Thus, combinations of ALK vaccine with TKIs and immune checkpoint blockade therapies might represent a powerful strategy for the treatment of ALK-driven NSCLC.

ALK-dependent control of hypoxia-inducible factors mediates tumor growth and metastasis.

Rearrangements involving the anaplastic lymphoma kinase (ALK) gene are defining events in several tumors, including anaplastic large-cell lymphoma (ALCL) and non-small cell lung carcinoma (NSCLC). In such cancers, the oncogenic activity of ALK stimulates signaling pathways that induce cell transformation and promote tumor growth. In search for common pathways activated by oncogenic ALK across different tumors types, we found that hypoxia pathways were significantly enriched in ALK-rearranged ALCL and NSCLC, as compared with other types of T-cell lymphoma or EGFR- and K-RAS-mutated NSCLC, respectively. Consistently, in both ALCL and NSCLC, we found that under hypoxic conditions, ALK directly regulated the abundance of hypoxia-inducible factors (HIF), which are key players of the hypoxia response in normal tissues and cancers. In ALCL, the upregulation of HIF1α and HIF2α in hypoxic conditions required ALK activity and its downstream signaling proteins STAT3 and C/EBPß. In vivo, ALK regulated VEGFA production and tumor angiogenesis in ALCL and NSCLC, and the treatment with the anti-VEGFA antibody bevacizumab strongly impaired ALCL growth in mouse xenografts. Finally, HIF2α, but not HIF1α, was required for ALCL growth in vivo whereas the growth and metastasis potential of ALK-rearranged NSCLC required both HIF1α and HIF2α. In conclusion, we uncovered an ALK-specific regulation of the hypoxia response across different ALK(+) tumor types and propose HIFs as a powerful specific therapeutic target in ALK-rearranged ALCL and NSCLC.

A better immune reaction to Erbb-2 tumors is elicited in mice by DNA vaccines encoding rat/human chimeric proteins.

The Erbb-2 (neu in rat and Her-2 in humans) tyrosine kinase receptor is an oncoantigen (i.e., a tumor-associated molecule directly involved in cancer progression). Because oncoantigens are self-tolerated molecules, to trigger a response circumventing tolerance, we generated two plasmids (RHuT and HuRT) coding for chimeric neu-Her-2 extracellular and transmembrane proteins that are expressed on the cell membrane of the transfected cells and recognized by monoclonal antibodies reacting against neu and Her-2. RHuT encodes a protein in which the 410 NH(2)-terminal residues are from the neu extracellular domain and the remaining residues from Her-2. Almost symmetrically, HuRT encodes for a protein in which the 390 NH(2)-terminal residues are from Her-2 and the remainder from neu. The ability of RHuT and HuRT to elicit a protective response to neu and Her-2 in wild-type mice and in transgenic mice tolerant to neu and Her-2 proteins was compared with that of plasmids coding for the fully rat or fully human extracellular and transmembrane domains of the Erbb-2 receptor. In most cases, RHuT and HuRT elicited a stronger response, although this chimeric benefit is markedly modulated by the location of the heterologous moiety in the protein coded by the plasmid, the immune tolerance of the responding mouse, and the kind of Erbb-2 orthologue on the targeted tumor.

Anaplastic lymphoma kinase: an oncogene for tumor vaccination.

The immune system contributes both to the maintenance of cancer in an equilibrium state and to the elimination of tumor cells. Specific antitumor vaccination could increase the intensity or modulate the quality of this immune response against transformed cells. Antitumor vaccination strategies rely upon the identification of one or multiple antigens that can serve to stimulate the immune system. This review will focus particularly on cancer vaccination strategies based on the use of DNA molecules and on the search for antigens that are required for the growth of tumor cells and that cannot be easily down-regulated by the cancer cells (oncoantigens). In addition, we will summarize some results on clinical trials that are currently exploiting selected antigens against tumors and on the recently identified anaplastic lymphoma kinase as a potential oncoantigen for selected types of human cancers.

DNA vaccines targeting tumor antigens to B7 molecules on antigen-presenting cells induce protective antitumor immunity and delay onset of HER-2/Neu-driven mammary carcinoma.

PURPOSE: Presentation of tumor antigens by professional antigen-presenting cells (APC) is critical for the induction of tumor-specific T-cell responses. To facilitate targeted delivery of tumor antigens to APC, we generated DNA vaccines that encode secreted fusion proteins consisting of the extracellular domain of CTLA-4 for binding to costimulatory B7 molecules on APC, fused to residues 1 to 222 of human ErbB2 (HER-2) or a corresponding 224 residues fragment of its rat homologue Neu. EXPERIMENTAL DESIGN: Induction of humoral and cellular immune responses and antitumoral activity of the DNA vaccines were tested in murine tumor models with transfected renal carcinoma cells expressing the respective antigens and in transgenic BALB-neuT mice developing spontaneous Neu-driven mammary carcinomas. RESULTS: Vaccination of BALB/c mice with CTLA-4-ErbB2(222) plasmid DNA markedly improved tumor-free survival on challenge with ErbB2-expressing Renca cells in comparison with untargeted ErbB2(222), accompanied by induction of stronger ErbB2-specific antibody and CTL responses. Likewise, a CTLA-4 vaccine carrying the unrelated NY-ESO-1 cancer-germline antigen was more effective than untargeted NY-ESO-1 in the protection of mice from challenge with NY-ESO-1-expressing tumor cells. Importantly, antitumoral activity of such a CTLA-4 fusion vaccine could be reproduced in immunotolerant BALB-neuT mice, where a corresponding CTLA-4-Neu(224) DNA vaccine markedly delayed the onset of spontaneous Neu-driven mammary carcinomas. CONCLUSIONS: Our results show that plasmid DNA vaccines for in vivo expression of tumor antigens targeted to APC induce potent immune responses and antitumoral activities, providing a rationale for further development of this approach for specific cancer immunotherapy.

ErbB2 transgenic mice: a tool for investigation of the immune prevention and treatment of mammary carcinomas.

The epidermal growth factor receptor belongs to a superfamily of receptor tyrosine kinases (RTK) that includes ErbB2. ErbB2 is involved in normal physiological processes, such as embryogenesis, cell proliferation, differentiation, adhesion motility, and apoptosis, while its malfunction or overexpression is responsible for development defects, diabetes, and cancer. The human ortholog of ErbB2 is referred as Her-2 (human ErbB2) while the rat ortholog is referred as neu (rat ErbB2). As ErbB2 is directly involved in carcinogenesis, mice transgenic for the rat neu oncogene allow straightforward assessment of the ability of drugs and vaccines to inhibit the progression of neu-driven cancer. Information from this model may provide indications on the efficacy of similar treatments in patients. This commentary provides key information regarding the use of these transgenic mouse models for evaluation of the efficacy of anti-tumor strategies.

Intramammary application of non-methylated-CpG oligodeoxynucleotides (CpG) inhibits both local and systemic mammary carcinogenesis in female BALB/c Her-2/neu transgenic mice.

CpG are powerful drugs activating the innate immune system. In this study, the ability of their intramammary administration in impeding the devastating progression of carcinogenesis in all the mammary glands of female BALB/c mice transgenic for the rat neu transforming oncogene was assessed. Starting when in situ carcinomas were scattered over all their mammary glands (week 10), mice received CpG injections in the stroma of the fourth left gland. Local neoplastic progression was inhibited by six monthly administrations. CpG not only delayed the onset of carcinomas in the injected gland, but also hampered their progression. Extended latency was observed for tumors in glands both close to and far from the injection site. When the experiment ended (week 45), no tumors were palpable in 67% of the injected glands and a markedly impaired tumor growth was evident in the others. An impressive local infiltrate of CD11b(+) cells with the morphologic features of macrophages, plasma cells, B220(+) B cells, and CD4(+) and CD8(+) T cells was quickly recruited to the CpG-treated glands. High quantities of IFN-gamma producing cells were only present in the ipsilateral axillary draining lymph nodes of the treated glands. Enhanced natural killer (NK) lytic activity was also detected in the spleens. Inhibition of progression was weaker when only four injections were given, and abolished by in vivo depletion of NK cells. CpG monotherapy is thus effective in an aggressive model of autochthonous cancer. The results strongly support the administration of CpG as a local monotherapy of multiple invasive microscopic lesions.

The anaplastic lymphoma kinase is an effective oncoantigen for lymphoma vaccination.

An ideal vaccination strategy against tumors relies on specific antigens that are required for tumor maintenance. For lymphoma, vaccination with subject-specific immunoglobulin idiotypes has had the most promising results. Here we show that DNA vaccination with plasmids encoding portions of the cytoplasmic domain of anaplastic lymphoma kinase (ALK), which has been translocated in different fusion proteins necessary for the growth of anaplastic large cell lymphoma (ALCL), protects mice from local and systemic lymphoma growth. The protection is potent and long lasting and elicits ALK-specific interferon-gamma responses and CD8+ T cell-mediated cytotoxicity. A combination of chemotherapy and vaccination significantly enhanced the survival of mice challenged with ALK+ lymphomas. These findings indicate that ALK represents an ideal tumor antigen for vaccination-based therapies of ALCL and possibly other ALK+ human tumors.

The adjuvant activity of BAT antibody enables DNA vaccination to inhibit the progression of established autochthonous Her-2/neu carcinomas in BALB/c mice.

Over the course of 33 weeks from birth, the mammary glands of virgin female BALB/c mice transgenic for the transforming rat Her-2/neu oncogene progress from atypical hyperplasia to invasive carcinoma. By week 12, all their mammary glands display many foci of in situ carcinoma. DNA vaccination at weeks 12 and 14 through in vivo electroporation of a plasmid encoding for the extracellular and transmembrane domain of the protein product of rat Her-2/neu oncogene kept 33% of mice tumor-free until week 35, when the experiment ended. To improve its efficacy the vaccine was combined with a T cell stimulatory monoclonal antibody (BAT). When each plasmid electroporation was followed by intravenous administration of 10 microg of BAT monoclonal antibody at weeks 13 and 15, 55% of mice remained tumor free (p < 0.0001) and stronger T cell and antibody-mediated immune responses were elicited. These data suggest that costimulation by BAT monoclonal antibody enables DNA vaccination to establish an effective protection against incipient carcinomas.