Transcriptomic Microarray Profile Analysis between Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) and TET2-Mutated Acute Myeloid Leukemia (AML)

Abstract Background: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic neoplasm involving skin lesions and disseminated disease into bone marrow, peripheral blood, and lymph nodes, characterized by poor clinical outcomes and no standard therapeutic approaches. BPDCN is characterized by the malignant proliferation of precursor plasmacytoid dendritic cells (pDCs). It is now classified by WHO 2016 as a separate entity under myeloid malignancies owing to its unique clinico-pathologic nature, greater understanding of its distinct clinical course, but with some noted clinical, morphologic, and molecular similarities to AML and myelodysplastic syndrome (MDS). One of the most common molecular mutations observed by next-generation sequencing in the vast majority of patients with BPDCN has been the presence of TET2 mutations and variants. Notably, somatic missense and truncating mutations in TET2 have been reported in patients with both BPDCN and AML, yet their differential responses to similar therapeutic regimens in clinical trial testing indicates that there are likely key underlying etiologies that are yet to be determined. Aims: We sought to investigate and identify critical differences between patients with BPDCN and AML at the molecular level, utilizing a series of advanced analyses including transcriptome microarray, serum multiplex immunoassays and cytokine analysis. Methods: In order to discern these differences, we profiled bone marrow, peripheral blood and serum samples from primary patients samples with BPDCN (N = 16) and TET2-mutated AML (AMLTET2m) (N = 9) using 3 different assays. We first ascertained somatic point mutations and copy number alterations of 300 genes in our BPDCN specimens using an in-house hematologic malignancy panel ("T300" panel). Next, we confirmed the prevalence of compound truncating TET2 mutations in patients with BPDCN and few copy number alterations in the genes profiled. We then used the transcriptome microarray (ThermoFisher Scientific ClariomTM D Pico Assay, and serum multiplex immunoassays (Cytokine/Chemokine/Growth Factor 45-Plex Human ProcartaPlex™ Panel 1 (ThermoFisher Scientific, formerly Affymetrix) with the addition of IL-3 Human ProcartaPlex™ Simplex Kit, formerly Affymetrix) to compare BPDCN specimens against those from TET2-mutated AML patients. Results: With the microarray analysis, we found 920 genes to be up-regulated and 791 genes down-regulated in BPDCN specimens as compared to AMLTET2m. We corroborated known differentially expressed marker genes: higher levels of IL3Ra and TCL1A and lower levels of MPO in BPDCN as compared to AMLTET2m specimens. Genes specific to dendritic cells (PTPRS, LTK, LAMP5) were highly expressed in BPDCN than in AMLTET2m specimens. Of interest, two of these genes, PTPRS and LTK, provide possible links to the skin lesions as PTPRS is implicated in the progression of melanoma and LTK is involved in pigmentation of melanocytes. The serum cytokine profile analysis showed significantly elevated levels of eotaxin and RANTES in the BPDCN cohort as compared to the AMLTET2m cohort (Figure 1a,b). Both of these are implicated in allergic and autoimmune reactions by behaving as eosinophil chemo-attractants. Along with the higher levels of PTPRS and dendritic nature of the tumor cells, these findings suggest a possible autoimmune background which exists in the context of disease. Conclusions: In this novel analysis, we observed elevated levels of eotaxin and RANTES in patients with BPDCN as compared to AMLTET2m. These findings may represent an important aspect of pDC functioning even outside of BPDCN, as pDCs may contribute to the pathogenesis of systemic lupus erythematosus (SLE), an autoimmune disorder with hallmark cutaneous lesions. Moreover, autoimmune pathologies have been hypothesized to damage the bone marrow and induce destruction of myeloid precursor cells. This may incorporate some of the dendritic cell nature since in its natural context, as pDCs serve to recognize foreign particles such as viruses and synthetic oligonucleotides through Toll-like Receptors TLR7/9. These findings suggest that further study into these markers are warranted in patients with BPDCN. Figure 1. Differential serum cytokine levels between BPDCN and AMLTET2m (a) Eotaxin (pg/mL), Wilcox rank test P < 0.01 (b) RANTES (pg/mL), Wilcox rank test P < 0.05. Disclosures Konopleva: Stemline Therapeutics: Research Funding. Pemmaraju:stemline: Consultancy, Honoraria, Research Funding; plexxikon: Research Funding; SagerStrong Foundation: Research Funding; daiichi sankyo: Research Funding; celgene: Consultancy, Honoraria; Affymetrix: Research Funding; samus: Research Funding; cellectis: Research Funding; abbvie: Research Funding; novartis: Research Funding.

Download Full-text

Features of non-activation dendritic state and immune deficiency in blastic plasmacytoid dendritic cell neoplasm (BPDCN)

Blood Cancer Journal ◽

10.1038/s41408-019-0262-0 ◽

2019 ◽

Vol 9 (12) ◽

Cited By ~ 3

Author(s):

Hannah C. Beird ◽

Maliha Khan ◽

Feng Wang ◽

Mansour Alfayez ◽

Tianyu Cai ◽

...

Keyword(s):

Bone Marrow ◽

Dendritic Cell ◽

Peripheral Blood ◽

Profile Analysis ◽

Hematologic Malignancy ◽

Plasmacytoid Dendritic Cell ◽

Serum Samples ◽

Molecular Features ◽

Cell Neoplasm ◽

Poor Outcomes

AbstractBlastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, male-predominant hematologic malignancy with poor outcomes and with just one recently approved agent (tagraxofusp). It is characterized by the abnormal proliferation of precursor plasmacytoid dendritic cells (pDCs) with morphologic and molecular similarities to acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)/chronic myelomonocytic leukemia (CMML) in its presentation within the bone marrow and peripheral blood. To identify disease-specific molecular features of BPDCN, we profiled the bone marrow, peripheral blood, and serum samples from primary patient samples using an in-house hematologic malignancy panel (“T300” panel), transcriptome microarray, and serum multiplex immunoassays. TET2 mutations (5/8, 63%) were the most prevalent in our cohort. Using the transcriptome microarray, genes specific to pDCs (LAMP5, CCDC50) were more highly expressed in BPDCN than in AML specimens. Finally, the serum cytokine profile analysis showed significantly elevated levels of eosinophil chemoattractants eotaxin and RANTES in BPDCN as compared with AML. Along with the high levels of PTPRS and dendritic nature of the tumor cells, these findings suggest a possible pre-inflammatory context of this disease, in which BPDCN features nonactivated pDCs.

Download Full-text

The diagnostics of blastic plasmocytoid dendritic cell neoplasm: report of five cases

Pediatric Hematology/Oncology and Immunopathology ◽

10.24287/1726-1708-2021-20-3-60-67 ◽

2021 ◽

Vol 20 (3) ◽

pp. 60-67

Author(s):

I. A. Demina ◽

S. A. Kashpor ◽

O. I. Illarionova ◽

M. E. Dubrovina ◽

A. A. Dudorova ◽

...

Keyword(s):

Bone Marrow ◽

Flow Cytometry ◽

Dendritic Cell ◽

Plasmacytoid Dendritic Cell ◽

Skin Lesions ◽

Flow Cytometry Data ◽

Hematological Disorders ◽

Pediatric Hematology ◽

National Medical ◽

Cell Neoplasm

The diagnosis of rare hematological disorders requires a comprehensive clinical and laboratory investigation with careful interpretation of all test results. Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is one of such rare entities. We have performed a retrospective analysis of the results of immunophenotyping, cytomorphology and cytogenetics of bone marrow tumor cells from 5 patients with BPDCN aged from 8 to 51 years. The study was approved by the Independent Ethics Committee of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. No specific characteristics of blasts were found. No correlation with the treatment and outcomes was noted as well: 3 patients died of progression or relapse (2 and 1, respectively). Bone marrow immunophenotyping is probably the most valuable laboratory test which allows physicians to establish the proper diagnosis in the absence of skin lesions. Flow cytometry immunophenotyping is the only technique used to determine the antigen profile that enables us to distinguish normal plasmacytoid dendritic cells from tumor ones by the presence (or absence) of the expression of CD2, CD7, CD38, CD56, CD303 etc. In the present paper, we provide a detailed description of five cases of BPDCN and main methods for flow cytometry data analysis. The parents of the patients agreed to use the information, including photos of children, in scientific research and publications.

Download Full-text

A rare case of blastic plasmacytoid dendritic cell neoplasm with deletion 7q.31, in the setting of heavy pre-treatment with alkylating chemotherapy

Journal of Oncology Pharmacy Practice ◽

10.1177/1078155216665245 ◽

2016 ◽

Vol 23 (7) ◽

pp. 552-556 ◽

Cited By ~ 2

Author(s):

Varinder Kaur ◽

Arjun Swami ◽

Atrash Shebli ◽

Sara Shalin ◽

Muthu Veeraputhiran ◽

...

Keyword(s):

Bone Marrow ◽

Dendritic Cell ◽

Rare Case ◽

De Novo ◽

Plasmacytoid Dendritic Cell ◽

Initial Response ◽

Skin Lesions ◽

Lymph Node Involvement ◽

Lymphoid Leukemia ◽

Cell Neoplasm

Blastic plasmacytoid dendritic cell neoplasm is rare myeloid malignancy clinically characterized by non-pruritic, violaceous and papulo-nodular skin lesions, together with bone marrow and lymph node involvement. Histologically, there is infiltration of dermis by neoplastic mono-nuclear CD4, CD56, CD123 co-expressing cells with epidermal sparing. Most commonly blastic plasmacytoid dendritic cell neoplasm presents as a de-novo condition, and treatment-related blastic plasmacytoid dendritic cell neoplasm is a rare phenomenon. Due to rarity of the disease, there is no established standard of care treatment. Both acute myeloid leukemia and acute lymphoid leukemia type induction regimens have been used for treatment of blastic plasmacytoid dendritic cell neoplasm, with initial response rate of 50%–80%. We present a rare case of therapy-associated blastic plasmacytoid dendritic cell neoplasm in a patient with remote history alkylating agent systemic therapy. A lag period of five to seven years and presence of deletion 7q.31 seen in bone marrow biopsy specimen in our patient are consistent with a likely therapy-associated etiology of his blastic plasmacytoid dendritic cell neoplasm.

Download Full-text

Blastic Plasmacytoid Dendritic Cell Neoplasm: Report of Three Cases.

Blood ◽

10.1182/blood.v114.22.4703.4703 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4703-4703

Author(s):

Paola Carluccio ◽

Mario Delia ◽

Anna Mestice ◽

Domenico Pastore ◽

Alessandra Ricco ◽

...

Keyword(s):

Bone Marrow ◽

Dendritic Cells ◽

Dendritic Cell ◽

Disease Progression ◽

Plasmacytoid Dendritic Cell ◽

Skin Lesions ◽

World Health ◽

Cell Neoplasm ◽

Blast Cells

Abstract Abstract 4703 The World Health Organization (WHO) recently published a revised, updated edition of the WHO Classification of Tumours of the Haematopoietic and Lymphoid Tissues, including new criteria for the recognition of some previously described neoplasms as well as clarification and refinement of the defining criteria for others. It also adds entities – some defined mainly by genetic and immunophenotypic features – that have only recently been characterized. Particularly, the diagnosis and classification of acute leukemias of ambiguous lineage is debated; among these: “blastic NK-cell lymphoma” and “agranular CD4+/CD56+ hematodermic neoplasms”. Both of them are now known to be, in virtually all cases, a tumor derived from precursors of a specialized subset of dendritic cells, plasmacytoid dendritic cells, and so are myeloid-related neoplasms defined as blastic plasmacytoid dendritic cell neoplasm (BPDCN). This is a clinically aggressive neoplasm that is usually characterized at onset by solitary or multiple skin lesions, often with associated regional lymphadenopathy, and frequently by involvement of the PB and BM. Leukemic cells show submembranous cytoplasmic vacuoles and pseudopodia-like extensions of agranular cytoplasm. The blasts in such cases do not express myeloperoxidase or nonspecific esterase, and are characterized by the expression of CD4, CD43, CD56, CD123, BDCA-2/CD303, TCL1, and CLA; CD7 and CD33 are not uncommonly expressed as well, and TdT is expressed in about 30% of cases. There is no expression of CD34 or CD117. Here we report three cases with clinical data, cytological and immunophenotypic findings strongly suggesting the diagnosis of BPDCN. Case 1 An 80 year-old-man was admitted to our institution on December 2006. He referred the occurrence of skin lesions since January 2005, when a diagnosis of extranodal B-cell non-Hodgkin lymphoma was made and treatment with conventional chemotherapy was performed, but without achieving any response. At our evaluation he presented leukocytosis (144 × 109/L) associated with purplish, firm nodules on the trunk, arms and face. Peripheral blood and bone marrow aspirate showed the presence of blast cells with a lymphoid appearance, granular periodic acid-Schiff (PAS) positivity and a high expression of CD33, CD4, and CD56. He was treated with AML-like therapy, but died of disease progression. Case 2 A 79-year old woman was admitted in December 2006 with a 2-month history of anemia, splenomegaly, and weight loss of 10 kg in the last year. Laboratory tests were as follows: Hb, 41 g/L; leukocytes, 2.5 × 109/L (with 10% of blast cells); platelets, 43 × 109/L. No lymphadenopathy or skin lesions were present. Bone marrow examination revealed 41% of small to medium-sized blast cells without Auer rods or granula and negative reactivity to myeloperoxidase, esterase and PAS. She was treated with an AML-like protocol; she achieved partial response, but died after three months, of disease progression. Case 3 A 69-year-old man was admitted to our Institution for cytopenia in June 2009. He referred the occurrence of brownish-purple firm nodules on the trunk since April 2009. At our evaluation he presented pancytopenia; bone marrow aspiration was performed and revealed infiltration by 65% of blasts with reticulated chromatin, evident nucleoli, a vacuolated cytoplasm and pseudopodia-like expansions. The blasts were negative for myeloperoxidase, monocyte esterase and PAS staining. Skin biopsy revealed a dermal infiltration by the same blastic-cell BM population. He underwent AML-like therapy and, although the skin lesions disappeared, 30% blastic bone marrow infiltration persisted. Morphological revision of these cases, selected for their peculiar immunophenotype reported in the following Table, revealed the same cytological features and cytochemical reactivity in cases 2 and 3; case 1 had a lymphoblastic-like morphology and showed PAS positivity, but the lack of cCD3 was not consistent with the diagnosis of ALL. All the cases were FLT3-ITD+. We suggest that a correct modern panel of MoAb with a careful morphological examination could help to pose the diagnosis of BPDCN, which typically affects older patients and is characterized by poor prognosis. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Diagnosis of Blastic Plasmacytoid Dendritic Cell Neoplasm By Using 10-Colour Flow Cytometry and Achievement of Remission By Hypercvad Therapy

Blood ◽

10.1182/blood.v124.21.2365.2365 ◽

2014 ◽

Vol 124 (21) ◽

pp. 2365-2365 ◽

Cited By ~ 1

Author(s):

Uday Deotare ◽

Elizabeth Hyjek ◽

Anna Porwit ◽

Rumina Musani ◽

David Barth ◽

...

Keyword(s):

Bone Marrow ◽

Flow Cytometry ◽

Overall Survival ◽

Dendritic Cell ◽

Research Funding ◽

Plasmacytoid Dendritic Cell ◽

Leukemic Cells ◽

Front Line ◽

Hla Dr ◽

Cell Neoplasm

Abstract Background: Although classified by WHO 2008 as belonging to the category “Acute myeloid leukemia and related precursor neoplasms”, Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) presents as an acute leukemia (AL) only in a minority of cases. There are only few studies describing the comprehensive immunophenotypic pattern of BPDCN in the bone marrow. Furthermore, given the rarity of this hematologic malignancy optimal frontline therapy is unclear. Patients and Methods: This retrospective analysis evaluates the diagnostic flow cytometry pattern and outcome of 9 patients who were diagnosed with BPDCN at the Princess Margaret Cancer Centre between December 2008 and June 2014. A four tube 10-color flow cytometry (FCM) panel has been used to correctly make the diagnosis of BPDCN in 6 patients, whereas a 5-colour panel was used in the remaining patients in conjunction with immunohistochemistry. The following markers were included in the10-color panel: Tube 1: CD65 FITC, CD13 PE, CD14 ECD, CD33 PC5.5, CD34 PC7, CD117 APC, CD7 A700, CD11b A750, CD16 PB, and CD45 KO; Tube 2: CD36 FITC, CD64 PE, CD56 ECD, CD33 PC5.5, CD34 PC7, CD123 APC, CD19 A700, CD38 A750, HLA-DR PB, and CD45 KO; Tube 3: CD71 FITC, CD11c PE, CD4 ECD, CD33 PC5.5, CD34 PC7, CD2 APC, CD10 A700, CD235a A750, CD15 PB, and CD45 KO; Tube 4:nuclear (n) TdT FITC, cytoplasmic (cyt.) MPO PE, CD14 ECD, CD33 PC5.5, CD34 PC7, cyt.CD79a APC, cyt.CD22 A700, CD19 A750, cyt.CD3 PB, and CD45 KO. Results: Median age was 66 years (range, 25 to 91 years); 3 patients were over the age of 70 years. Fifty-six percent were males. All presented with skin lesions and 78% presented each with lymphadenopathy and bone marrow involvement. Cytogenetics were poor-risk in 2 patients, intermediate-risk in 3 and unknown or inconclusive in 4. By 10-color FCM, leukemic cells were in the blast gate (CD45dim/low SSC) and were positive for CD4(bright), CD33(dim), CD56(heterogenous), CD123(bright), CD36, CD38, HLA-DR, CD71, but negative for CD10, CD11b, CD13, CD14, CD15, CD16, CD19, CD34, CD64, CD65, CD235a. Other markers, such as cyt.MPO, cyt.CD3, cyt.CD22 and nTdT were negative, while dim cyt.CD79a was seen in 3 cases. CD7 expression was found in 5 cases, whereas CD2 and CD117 were found in single cases only. BM involvement by BPDCN leukemic cells ranged from 27% to 92% of the marrow cellularity. Skin involvement showed dense infiltrate of cells with blastoid morphology and characteristic grenz zone. Seven patients received front-line induction therapy with HyperCVAD with an overall response rate of 86% (4 complete remissions (CR), 2 unconfirmed CRs). One patient died of multi-organ failure during induction. Three of 6 responders underwent planned allogeneic hematopoietic cell transplantation (HCT); 1 patient has since died of acute graft versus host disease (GVHD), whereas 2 are alive in remission with chronic GVHD, 12 and 14 months post transplant with complete donor chimerism. One transplant ineligible patient relapsed 22 months after achievement of CR1. Median follow-up of all patients was 12 months with a overall survival at 1 year of 59.3% for the entire group. Patients who underwent allogeneic HCT had overall survival at 1 year of 66.7% and for the chemotherapy group was 27.8% at 1 year.(p=0.34). Conclusion: An accurate diagnosis of BPDCN can be made by 10-colour FCM using a 4-tube acute leukemia panel. BPDCN demonstrates a characteristic pattern of antigen expression . Although front-line induction chemotherapy with HyperCVAD can yield high CR rates, allogeneic HCT should be performed in first CR for transplant eligible patients, as this appears to be required for long term durable remissions. For transplant ineligible or relapsed BPDCN patients, there is an unmet need for novel therapeutic agents. Disclosures Porwit: Beckman-Coulter: Speakers Bureau. Gupta:Novartis: Consultancy, Honoraria, Research Funding; Incyte Corporation: Consultancy, Research Funding.

Download Full-text

Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) Is Highly BCL-2 Dependent and Sensitive to Venetoclax

Blood ◽

10.1182/blood.v128.22.4045.4045 ◽

2016 ◽

Vol 128 (22) ◽

pp. 4045-4045 ◽

Cited By ~ 1

Author(s):

Joan Montero ◽

Jason Stephansky ◽

Tianyu Cai ◽

Gabriel K. Griffin ◽

Katsuhiro Togami ◽

...

Keyword(s):

Bone Marrow ◽

Dendritic Cell ◽

Cytochrome C ◽

Board Of Directors ◽

Research Funding ◽

Plasmacytoid Dendritic Cell ◽

Cytochrome C Release ◽

Advisory Committees ◽

Cell Neoplasm ◽

Peptide Stimulation

Abstract Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a particularly aggressive hematologic malignancy with median survival of <12 months and no standard therapy. BPDCN involves the skin in nearly all patients, and frequently infiltrates bone marrow and lymph nodes. Its normal counterpart may be the plasmacytoid dendritic cell (pDC), leading to the name BPDCN. Outcomes are poor with cytotoxic chemotherapy. An interleukin 3-diphtheria toxin fusion (SL-401) has activity in BPDCN (Frankel, Blood 2014), but additional novel agents are urgently needed. BPDCN over-expresses the anti-apoptotic protein BCL-2 compared to normal pDCs (Sapienza, Leukemia 2014). We confirmed this by RNA-sequencing 12 BPDCNs and pDCs from 4 normal donors (reads/kb mapped [RPKM] 22.7 vs 1.33, P=0.0005). BPDCN shares some genetic characteristics with myeloid malignancies, and some acute myeloid leukemias (AMLs) are dependent on BCL-2. We performed RNA-seq on 6 BPDCN and 16 AML patient-derived xenografts (PDXs) and found higher BCL-2 expression in BPDCN (RPKM 48.2 vs 11.5, P=0.0005). We analyzed BCL-2 expression by immunohistochemistry in patient skin and bone marrow biopsies and found that all BPDCNs had BCL-2 staining that was equivalent to or stronger than that of any AMLs. We next tested BPDCN cell lines, primary patient samples, and patient-derived xenografts (PDXs) for BCL-2 dependence and sensitivity to the BCL-2 inhibitor venetoclax (previously ABT-199). Using BH3 profiling, we found that BPDCN is markedly dependent on BCL-2 to prevent mitochondrial cytochrome c release in response to apoptotic stimuli. In comparison to AML, BPDCN had significantly more cytochrome c release after BAD peptide stimulation (81.1% vs 11.8%, P<0.0001), suggesting greater dependency on BCL-2 and/or BCL-XL. BPDCN was uniformly sensitive to treatment with venetoclax in vitro, in cell lines and primary cells, as measured by direct cytotoxicity and Annexin V apoptosis assays. We used dynamic BH3 profiling (Montero, Cell 2015) in primary BPDCNs and PDXs (n=7) to measure early apoptotic signals after 4-hr exposure to venetoclax, avoiding the need for prolonged culture. BPDCNs were more likely than AMLs to undergo cytochrome c release in response to BIM peptide stimulation after 4 hours of venetoclax (increase in apoptotic potential, or "delta priming" 63.4% vs 14.5%, P<0.0001). Targeted sequencing of the BPDCNs found various combinations of mutations in TP53, FLT3, JAK2, SRSF2, TET2, ASXL1, IDH2, GNB1, NRAS and/or ZRSR2. All responded equally to venetoclax, suggesting the response was independent of genotype. Next we treated two BPDCN PDXs in vivo in NSG mice with oral venetoclax (100 mg/kg/day x 28 days). PDX genetics were, PDX1: ASXL1 G646fs*, NRAS G13D, JAK2 V617F, TET2 D1017fs*, and TET2 Q1687fs*; PDX2: IDH2 R140Q, TP53 S241F, TP53 C176Y, and ZRSR2 S188*. Venetoclax caused significant reductions in BPDCN burden in peripheral blood, spleen, and bone marrow after 21 days of therapy in both models. Overall survival was improved in venetoclax compared to vehicle treated animals in a leukemia-watch cohort (57 vs 36 days, P=0.0025). On the basis of these findings, we treated a relapsed BPDCN patient with venetoclax. He is an 80 year-old male who had received 3 prior lines of therapy. He had extensive skin disease with multiple cutaneous tumors, lymph node involvement, and >80% bone marrow blasts. His BPDCN carried the mutations ASXL1 Y581fs*, ASXL1 E553fs*, GNB1 K57E, IDH2 R140W, and NRAS G12D, and expressed high levels of BCL-2 protein in bone marrow and skin. BH3 profiling of a skin tumor biopsy revealed marked BCL-2 dependence and dynamic BH3 response to venetoclax (4 hr delta priming 55.6%). We treated him using a regimen recently FDA-approved for chronic lymphocytic leukemia (CLL) consisting of weekly dose escalation (20 -> 50 -> 100 -> 200 mg), to a target dose of 400 mg daily. At the time of this writing, he had reached 200 mg without significant toxicity, including no evidence of tumor lysis syndrome. His skin disease has responded remarkably (Figure), with the first response evident within 10 days. Our data suggests that BPDCN is highly sensitive to BCL-2 inhibition, which could provide an urgently needed new treatment for patients with this disease. We propose that BCL-2 inhibition should undergo expedited clinical evaluation in BPDCN. In addition, this case offers an example of precision cancer medicine by functional rather than genetic means. Figure Figure. Disclosures Davids: Infinity: Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Gilead: Honoraria; Janssen: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria, Research Funding; TG Therapeutics: Honoraria, Research Funding; Abbvie: Consultancy, Honoraria. Stone:ONO: Consultancy; Novartis: Consultancy; Amgen: Consultancy; Seattle Genetics: Consultancy; Roche: Consultancy; Celator: Consultancy; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy; Jansen: Consultancy; Pfizer: Consultancy; Juno Therapeutics: Consultancy; Merck: Consultancy; Sunesis Pharmaceuticals: Consultancy; Xenetic Biosciences: Consultancy. Konopleva:Reata Pharmaceuticals: Equity Ownership; Abbvie: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Stemline: Consultancy, Research Funding; Eli Lilly: Research Funding; Cellectis: Research Funding; Calithera: Research Funding. Letai:AbbVie: Consultancy, Research Funding; Astra-Zeneca: Consultancy, Research Funding; Tetralogic: Consultancy, Research Funding. Lane:N-of-1: Consultancy; Stemline Therapeutics: Research Funding.

Download Full-text

Pre-Clinical Studies of Anti-CD123 CAR-T Cells for the Treatment of Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN)

Blood ◽

10.1182/blood.v128.22.4039.4039 ◽

2016 ◽

Vol 128 (22) ◽

pp. 4039-4039 ◽

Cited By ~ 12

Author(s):

Tianyu Cai ◽

Roman Galetto ◽

Agnès Gouble ◽

Julianne Smith ◽

Antonio Cavazos ◽

...

Keyword(s):

Bone Marrow ◽

T Cells ◽

Dendritic Cell ◽

Research Funding ◽

Plasmacytoid Dendritic Cell ◽

Newly Diagnosed ◽

Car T Cells ◽

Car T ◽

Cell Neoplasm

Abstract Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive hematologic malignancy which originates from the precursors of plasmacytoid dendritic cells. Data on the biology of BPDCN are limited, patient outcomes have historically been poor and there remains no established standard of care. CD123/IL3Rα is overexpressed in nearly 100% of patients with BPDCN. Considering the urgent unmet medical need for patients with BPDCN, targeting CD123 emerged as an attractive therapeutic target given its accessibility (cell surface) and differential expression (markedly over-expressed on BDPCN blasts as compared to normal hematopoietic stem cell compartment). UCART123 (CD123CAR/RQR8+_TCRαβ-_T-cells) are genetically modified allogeneic T-cells (obtained from healthy volunteer donors by leukapheresis) containing (i) an anti-CD123 CAR (CD123 scFv-41BB-CD3z) and (ii) an RQR8 depletion ligand that confers susceptibility to rituximab. The cell surface expression of the T cell receptor (TCR) is depleted through the inactivation of the TCRa constant (TRAC) gene using Cellectis' TALEN® technology. In this study, we examined efficacy of this first allogenic anti-CD123 CAR-T cells in pre-clinical models of BPDCN. We first analysed the level of expression of CD123 in the bone marrow of 8 patients with newly diagnosed BPDCN, and compared with CD123 expression on blasts of 28 newly diagnosed AML patients. CD123 expression levels were significantly higher in BPDCN (mean fluorescence intensity (MFI) range 3,484-17,937) compared to AML (MFI range 360-5,073) (p<0.01). In vitro cytotoxic activity of UCART123 cells was evaluated by co-culturing UCART123 cells with primary human BPDCN, at a 10:1 effector to target ratio, using flow cytometry. The results show significant cytotoxic activity of UCART123 cells against BPDCN samples compared to cells co-cultured with non-transduced TCRab- T-cells (NTD) (Fig. 1A). We next evaluated antigen-specific UCART123 cell degranulation by staining of CD107α, a lysosomal associated membrane protein residing in cytolytic granule membranes. The results indicated that specific degranulation of UCART123 cells is observed upon co-culture with CD123 (+) target cells. The capacity of UCART123 cells to secrete cytokines, in particular IFNγ, in response to specific stimulation with CD123 (+) BPDCN cells was examined using a BioLegend's LEGENDplexTM assay. UCART123 cells stimulated by CD123 (+) BPDCN cells, but not NTD cells, secreted high levels of IFNγ in the culture supernatants (Fig. 1B). To evaluate in vivo anti-tumor activity of UCART123 cells, we established patient-derived xenograft (PDX) from a patient with relapsed BPDCN in NSG-SGM3 mice. Upon engraftment, mice were randomized into 4 groups (9 mice/group). Mice received either a single tail vein injection of vehicle, 10×106 NTD T-cells, and 3×106 or 10×106 UCART123 cells. All mice in vehicle-treated group and in the group that received 10×106 NTD cells died by day 53, with high tumor burden of BPDCN detected in peripheral blood, spleen and bone marrow. Both cell doses of UCART123 significantly extended mice survival (Fig. 1C) and reduced or eliminated circulating BPDCN cells. 57 days after UCART123 cells injection, one mouse from UCART123 10×106 group was sacrificed. UCART123 cells were detected in spleen (16.4% CAR+ cells) and bone marrow (1.1% CAR+ cells) using human CD5 antibody or CD123-Fc protein. In summary, UCART123 causes specific killing of BPDCN cells, associated with antigen-specific T-cell degranulation and robust levels of IFNg production. Our preliminary data indicate persistence of UCART123 cells in vivo in an NSG-S model of primary BPDCN. Most importantly, UCART123 therapy results in BPDCN eradication and long-term disease-free survival in primary BPDCN PDX mice. Additional PDX studies are ongoing and will be presented. These results demonstrate pre-clinical proof-of principle of high anti-BPDCN activity of UCART123 allogeneic CAR T-cells, and warrant further clinical testing of this approach in human clinical trials in BPDCN. Disclosures Galetto: Cellectis SA: Employment. Gouble:Cellectis: Employment. Smith:Cellectis SA: Employment. Lane:Stemline Therapeutics: Research Funding; N-of-1: Consultancy. Guzman:Cellectis: Research Funding. Konopleva:Cellectis: Research Funding; Calithera: Research Funding.

Download Full-text

A very rare case of FLT3-D835 positive blastic plasmacytoid dendritic cell neoplasm

Archive of Clinical Cases ◽

10.22551/2020.29.0704.10174 ◽

2020 ◽

Vol 7 (4) ◽

pp. 57-62

Author(s):

Vlad Andrei Cianga ◽

Cătălin Doru Dănăilă ◽

Ion Antohe

Keyword(s):

Dendritic Cell ◽

Rare Case ◽

Elderly Population ◽

Hematological Malignancies ◽

Plasmacytoid Dendritic Cell ◽

The Elderly ◽

Skin Lesions ◽

Response To Treatment ◽

Cell Neoplasm ◽

Immuno Histochemistry

Blastic plasmacytoid dendritic cell neoplasms (BPDCNs) are extremely rare and aggressive hematological malignancies that derive from precursors of plasmacytoid dendritic cells (pDC) and frequently involve skin lesions and bone marrow infiltration. They mostly affect the elderly population and the prognosis is poor with the therapeutic choices currently available. Diagnosis is made with the help of tools such as immuno-histochemistry and flow cytometry. Here, we present a particular case of BPDCN with a positive FLT3-D835 mutation and we discuss the possible impact this may have on the evolution of the disease and response to treatment.

Download Full-text