Morten Orebo Holmström

The CALR exon 9 mutations are shared neoantigens in patients with CALR mutant chronic myeloproliferative neoplasms

The CALR exon 9 mutations are shared neoantigens in patients with CALR mutant chronic myeloproliferative neoplasms

The JAK2V617F mutation is a target for specific T cells in the JAK2V617F-positive myeloproliferative neoplasms

The JAK2 V617F mutation is a target for specific T cells in the JAK2 V617F-positive myeloproliferative neoplasms

Causes of early death in multiple myeloma patients who are ineligible for high-dose therapy with hematopoietic stem cell support: A study based on the nationwide Danish Myeloma Database

To the Editor: Hodgkin lymphoma (HL) is a B-cell derived lymphoid malignancy that accounts for about 10% of all lymphomas. Despite most of patients being cured by modern regimens of chemotherapy and radiotherapy (RT), nearly 20% show primary refractoriness or relapse after initial remission. In these cases second-line chemotherapy followed by autologous stem cell transplantation (ASCT) consolidation leads in nearly 50% of patients to a long lasting remission. For patients with HL relapsed/refractory (R/R) to more than two lines of therapy, there is no standard approach and prognosis is generally dismal. Therapeutic options include palliative chemotherapy, radiotherapy, and transplant procedures. More recently, Brentuximab Vedotin (BV), an anti-CD30 monoclonal antibody conjugated with Auristatin, showed therapeutic activity in 75% of patients with HL R/R to ASCT, with 35% complete response (CR) and median progression-free survival (PFS) of nearly 6 months [1]. Limited data are available regarding the combination of BV with chemotherapeutic agents while, the combination of BV with RT has not been reported so far. A 45-year-old male, with no significant comorbidities, was referred at our Centre on August 2013 for onset of multiple lympho-adenopaties (size varying from 2 to 7 cm and involving bilateral the cervical area and the right axillary) associated with fever, night sweats, fatigue, mild cough, and mild skin itching. Total white blood cell count was 39 3 10/L (90% neutrophils, 4% lymphocytes), while hemoglobin and platelet count were 98 g/L and 635 3 10/L, respectively; erythrocyte sedimentation rate was 91 mm/hr. After lateral cervical lymphonode biopsy and standard staging, the patient was diagnosed to have a sclero-nodular, classic HL, stage IIIs (spleen) B. The patient was started on standard ABVD chemotherapy program (Dacarbazine, Bleomycin, Vinblastine, and Doxorubicin) with rapid resolution of systemic symptoms and lymphonodes disappearance. A CT-PET evaluation after two cycles showed a picture of response with FDG uptake lower than liver (Deauville Score 3). After the fourth planned ABVD course, the patient had evidence of supradiaphragmatic progression with recurrence of right supraclavicular, axilla, and mediastinal involvement. A lymphonode biopsy confirmed the initial diagnosis of scleronodular classic HL. The patient was treated in December 2013 and January 2014 with one course of IGEV (Vinorelbine, Ifosfamide, Metilprednisolone and Gemcitabine) and one course of DHAP chemotherapy (Dexamethasone, Cisplatin, Cytosine Arabinoside) each, with no response and further clinical and radiological evidence of rapid progression with reappearance of fever, itching, and lymphoadenopaties in all supradiaphragmatic areas with bulky right axillary involvement (12 cm 3 10 cm). Based on the disease’s status of chemoresistance, a haploidentical stem cell transplant (SCT) with the patient’s sister was considered. To induce a pre-transplant condition of response, and because of the high level of aggressiveness of the disease with rapid lymphnodes enlargement, a combination treatment with BV and extended field (EF) RT was started. From February to April 2014 the patient received four administrations of BV (1.8 mg/kg) every 21 days with concomitant classical mantle field RT at a dose of 36 Gy in 20 fractions. Hematological toxicity experienced during the therapy was mild, with Grade 2 anemia only after course 1 and 2, and no neutropenia or thrombocytopenia. There were no infective complication or any other major adverse effects to BV or RT, and, in particular, no clinical or functional signs of pulmonary toxicity. The patient showed rapid resolution of the clinical symptoms and progressive and gradual decrease of the size of’ the right axillary lymphoadenopathy. Pretransplant restaging documented a partial response status (according to Cheson 2007) due to the persistence of a residual single right axillary lymphoadenopathy of 3 cm in size. This status of improvement allowed, in May 2014, to proceed with haplo-identical SCT with no major complications. At present, 6 months after the end of BV plus EF-RT and 5 months after SCT, the patient is in good clinical conditions and in a complete response status. Patients with R/R HL have a poor prognosis and no standard treatment has been established so far. Allogeneic SCT seems to be a suitable treatment option for patients with a pre-SCT response condition, with nearly 30–40% PFS. Due to the good safety profile, BV is frequently associated with other systemic therapies. In our patient, the association of BV with EF RT allowed the patient to receive subsequent consolidation treatment with haplo-identical SCT. Further studies investigating the combination of RT with BV in HL are warranted.

Differential Dynamics of CALR Mutant Allele Burden in Myeloproliferative Neoplasms during Interferon Alfa Treatment

Discovery of somatic mutations in the calreticulin gene (CALR) has identified a subgroup of Philadelphia-negative chronic myeloproliferative neoplasms (MPN) with separate haematological characteristics and prognosis. CALR mutations serve as novel markers both of diagnostic value and as targets for monitoring molecular responses during therapy. Interferon-α (IFN) selectively targets the malignant clone in a subset of MPN patients and can induce both haematological and molecular remissions in CALR mutated essential thrombocythemia (ET) patients. We investigated the response to IFN in a cohort of 21 CALR mutated MPN patients including ET, prefibrotic primary myelofibrosis (pre-PMF), and primary myelofibrosis (PMF) with a median follow-up of 31 months. For evaluation of a molecular response, we developed highly sensitive quantitative PCR (qPCR) assays for monitoring the mutant allele burden of the two most prevalent CALR mutations (type 1 and type 2). Thirteen patients (62%) experienced a decrease in the mutant allele burden with a median decline of 29% from baseline. However, only four patients, including patients with ET, pre-PMF, and PMF diagnosis, achieved molecular responder (MR) status with >50% reduction in mutant allele burden according to European LeukemiaNet (ELN) guidelines. MR patients displayed significant differences in the dynamics of the CALR mutant load with regard to time to response and dynamics in mutant allele burden after discontinuation of IFN treatment. Furthermore, we highlight the prognostic value of the CALR mutant allele burden by showing a close association with leucocyte- and platelet counts, hemoglobin concentration, in addition to plasma lactate dehydrogenase (LDH) irrespective of molecular response and treatment status.

The Danish National Multiple Myeloma Registry

Aim The Danish National Multiple Myeloma Registry (DMMR) is a population-based clinical quality database established in January 2005. The primary aim of the database is to ensure that diagnosis and treatment of plasma cell dyscrasia are of uniform quality throughout the country. Another aim is to support research. Patients are registered with their unique Danish personal identification number, and the combined use of DMMR, other Danish National registries, and the Danish National Cancer Biobank offers a unique platform for population-based translational research. Study population All newly diagnosed patients with multiple myeloma (MM), smoldering MM, solitary plasmacytomas, and plasma cell leukemia in Denmark are registered annually; ~350 patients. Amyloid light-chain amyloidosis, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome), monoclonal gammopathy of undetermined significance and monoclonal gammopathy of undetermined significance with polyneuropathy have been registered since 2014. Main variables The main registered variables at diagnosis are patient demographics, baseline disease characteristics, myeloma-defining events, clinical complications, prognostics, first- and second-line treatments, treatment responses, progression free, and overall survival. Descriptive data Up to June 2015, 2,907 newly diagnosed patients with MM, 485 patients with smoldering MM, 64 patients with plasma cell leukemia, and 191 patients with solitary plasmacytomas were registered. Registration completeness of new patients is ~100%. A data validation study performed in 2013–2014 by the Danish Myeloma Study Group showed >95% data correctness. Conclusion The DMMR is a population-based data validated database eligible for clinical, epidemiological, and translational research.

Frequent adaptive immune responses against arginase-1

ABSTRACT The enzyme arginase-1 reduces the availability of arginine to tumor-infiltrating immune cells, thus reducing T-cell functionality in the tumor milieu. Arginase-1 is expressed by some cancer cells and by immune inhibitory cells, such as myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs), and its expression is associated with poor prognosis. In the present study, we divided the arginase-1 protein sequence into overlapping 20-amino-acid-long peptides, generating a library of 31 peptides covering the whole arginase-1 sequence. Reactivity towards this peptide library was examined in PBMCs from cancer patients and healthy individuals. IFNγ ELISPOT revealed frequent immune responses against multiple arginase-1-derived peptides. We further identified a hot-spot region within the arginase-1 protein sequence containing multiple epitopes recognized by T cells. Next, we examined in vitro-expanded tumor-infiltrating lymphocytes (TILs) isolated from melanoma patients, and detected arginase-1-specific T cells that reacted against epitopes from the hot-spot region. Arginase-1-specific CD4+T cells could be isolated and expanded from peripheral T cell pool of a patient with melanoma, and further demonstrated the specificity and reactivity of these T cells. Overall, we showed that arginase-1-specific T cells were capable of recognizing arginase-1-expressing cells. The activation of arginase-1-specific T cells by vaccination is an attractive approach to target arginase-1-expressing malignant cells and inhibitory immune cells. In the clinical setting, the induction of arginase-1-specific immune responses could induce or increase Th1 inflammation at the sites of tumors that are otherwise excluded due to infiltration with MDSCs and TAMs.

Spontaneous T-cell responses against the immune check point programmed-death-ligand 1 (PD-L1) in patients with chronic myeloproliferative neoplasms correlate with disease stage and clinical response

ABSTRACT The Chronic Myeloproliferative Neoplasms (MPN) are cancers characterized by hyperinflammation and immune deregulation. Concurrently, the expression of the immune check point programmed death ligand 1 (PD-L1) is induced by inflammation. In this study we report on the occurrence of spontaneous T cell responses against a PD-L1 derived epitope in patients with MPN. We show that 71% of patients display a significant immune response against PD-L1, and patients with advanced MPN have significantly fewer and weaker PD-L1 specific immune responses compared to patients with non-advanced MPN. The PD-L1 specific T cell responses are CD4+ T cell responses, and by gene expression analysis we show that expression of PD-L1 is enhanced in patients with MPN. This could imply that the tumor specific immune response in MPN could be enhanced by vaccination with PD-L1 derived epitopes by boosting the anti-regulatory immune response hereby allowing tumor specific T cell to exert anti-tumor immunity.

Spontaneous T-cell responses against Arginase-1 in the chronic myeloproliferative neoplasms relative to disease stage and type of driver mutation

ABSTRACT Compelling evidence supports the existence of a profound immune dysregulation in patients with chronic myeloproliferative neoplasms (MPN). Increased Arginase-1 expression has been described in MPN patients and in solid cancers. This increase contributes to an immunosuppressive tumor microenvironment in MPN patients because of L-arginine depletion by Arginase-1-expressing regulatory cells and cancer cells, which subsequently limits the activation of circulating effector cells. In the present study, we demonstrate that Arginase-1-derived peptides are recognized by T cells among peripheral mononuclear blood cells from MPN patients. We characterized the Arginase-1-specific T cells as being CD4+ and found that the magnitude of response to the Arginase-1 peptides depends on disease stage. Activation of Arginase-1-specific T cells by vaccination could be an attractive novel immunotherapeutic approach to targeting malignant and suppressive cells in MPN patients in combination with other immunotherapeutics.

The inhibitory checkpoint, PD-L2, is a target for effector T cells: Novel possibilities for immune therapy

ABSTRACT Cell surface molecules of the B7/CD28 family play an important role in T-cell activation and tolerance. The relevance of the PD-1/PD-L1 pathway in cancer has been extensively studied whereas PD-L2 has received less attention. However, recently the expression of PD-L2 was described to be independently associated with clinical response in anti-PD1-treated cancer patients. Here, we investigated whether PD-L2 might represent a natural target that induces specific T cells. We identified spontaneous specific T-cell reactivity against two epitopes located in the signal peptide of PD-L2 from samples from patients with cancer as well as healthy individuals ex vivo. We characterized both CD8+ and CD4+ PD-L2-specific T cells. Interestingly, the epitope in PD-L2 that elicited the strongest response was equivalent to a potent HLA-A2-restricted epitope in PD-L1. Importantly, PD-L1-specific and PD-L2-specific T cells did not cross-react; therefore, they represent different T-cell antigens. Moreover, PD-L2-specific T cells reacted to autologous target cells depending on PD-L2 expression. These results suggested that activating PD-L2 specific T cells (e.g., by vaccination) might be an attractive strategy for anti-cancer immunotherapy. Accordingly, PD-L2 specific T cells can directly support anti-cancer immunity by killing of target cells, as well as, indirectly, by releasing pro-inflammatory cytokines at the microenvironment in response to PD-L2-expressing immune supressive cells.

The JAK2V617F and CALR exon 9 mutations are shared immunogenic neoantigens in hematological malignancy

ABSTRACT Approximately 90% of patients with the hematological malignancies termed the chronic myeloproliferative neoplasms harbor either the JAK2V617F-mutation or CALR exon 9 mutation. Both of these are recognized by T-cells, which make the mutations ideal targets for cancer immune therapy as they are shared antigens.