Biology of MDS/MPN overlap syndromes (except CMML) Andreas Reiter Haematology and Oncology University Medical Center Mannheim Ruprecht-Karls-University Heidelberg Germany

WHO 2008: Myeloid Neoplasms AML MDS Myeloid neoplasms MDS/MPN MPN MLN-eo aCML CML PMF CEL PDGFRA MDS/MPNu PV CNL MCD PDGFRB ( RARS-T ) ET MPNu FGFR1 CMML JMML

Diagnostic algorithm of MDS/MPN WBC >13x109/l or platelets >450x109/l At least one cytopenia: Hb <13/<12g/dl (m/f) Platelets <140x109/l WBC <1.8x109/l Dysplasia >10% in at least one lineage MDS/MPN Platelets >450x109/l Anemia and >15% ring sideroblasts WBC >13x109/l Dysplastic granulopoiesis >10% Myeloid precursors >10% RARS-T Atypical CML Monocytosis >1x109/l (and >10%) Dysplasia in at least one lineage or Cytogenetic or molecular aberration CMML

Median survival (months) Survival in MDS/MPN Median survival (months) aCML 25 (22-77) RARS-T 46 (39-82) MDS/MPNu <5% blasts >5% blasts 20 31 8 CMML CMML-1 CMML-2 14 (10-32) 19 13 Orazi A and Germing U, Leukemia, 2008 Breccia et al, Haematologica, 2006 Sekeres M, ASCO Annual Meeting, 2013

AML-free and overall survival in atypical CML and MDS/MPNu  Wang et al, Blood, in press

MDS/MPN-U: natural history and clinical outcome by treatment strategy MDS/MPN-U without RARS-T (n=85) Median age 70 years (22-90), 90% >60 years JAK2 V617F positive (17/56, 30%) No treatment regimen significantly improved response Hypomethylating agents (n=36, 42%) Immunomodulatory drugs (n=13, 15%) Allogeneic stem cell transplant (n=5, 6%) Median OS 12.4 months (0.3–138.7) MDS-IPSS and MDA global score provided statistical significance in univariate analysis, only thrombocytosis (52.5 vs. 11.9 months, p<0.001) was prognostic in multivariate analysis Ongoing clinical trial incorporating the combination of ruxolitinib and azacitidine DiNardo et al., Leukemia 28, 961-4, 2014

Mutations and prognosis in RARS/RARS-T JAK2 V617F mutation ~60% SF3B1 mutation >80% MPL W515 mutation ~ 5% High-risk: Age >80 years SF3B1 wt JAK2 wt Broséus et al, Leukemia 2013

Molecular genetics of RARS/RARS-T Somatic mutation SF3B1 (60-80%): mitochondrial iron overload, ineffective erythropoiesis, anemia Somatic mutation in JAK2 or MPL (70-80%): thrombocytosis Hematopoietic stem cell Ring sideroblasts and ineffective erythropoiesis (myelodysplastic features of RARS) Ring sideroblasts and thrombocytosis (myelodysplastic & myeloproliferative features of RARS-T) Cazzola et al. Blood 121, 260-9, 2013 8

Molecular genetics of atypical CML SETBP1 mutations in ≈25% of aCML SETBP1 Piazza R et al, Nat Genetics, 2013 Makishima H et al, Nat Genetics, 2013

SETBP1 mutation in atypical CML WBC (p=0.008) Hb (p=0.44) Platelets (p=0.16) SETBP1- = 77 months SETBP1+ = 22 months p=0.01, HR=2,27 Piazza et al, Nat Genetics, 2013

Diagnostic algorithm of MDS/MPN WBC >13x109/l or platelets >450x109/l At least one cytopenia: Hb <13/<12g/dl (m/f) Platelets <140x109/l WBC <1.8x109/l Dysplasia >10% in at least one lineage WBC >25x109/l Mature neutrophils and bands Leukocytes appear toxic No precursors No dysgranulopoiesis MDS/MPN CNL Platelets >450x109/l Anemia and >15% ring sideroblasts WBC >13x109/l Dysplastic granulopoiesis >10% Myeloid precursors >10% RARS-T Atypical CML Monocytosis >1x109/l (and >10%) Dysplasia in at least one lineage or Cytogenetic or molecular aberration CMML

aCML vs. CNL aCML CNL

Molecular characteristics of aCML and CNL CSF3R SETBP1 Reference CNL aCML Maxson et al, NEJM, 2013; Gotlib et al, Blood, 2013 8/9 (89%) 8/20 (40%) 5/9 (56%) 3/20 (15%) Pardanani et al, Leukemia, 2013 10/12 (83%) 0/19 (0%) 4/12 (33%) Meggendorfer et al, ASH 2013 7/20 (35%) 2/60 (3%) 2/19 (11%) 19/60 (32%) Piazza et al, ASH 2013 N/A 8/65 (12%) 18/65 (28%) Piazza et al, Nature Genetics, 2013 17/70 (24%) Courtesy of J. Gotlib

Molecular characteristics of aCML and CNL ASXL1 SETBP1 CSF3R SRSF2 aCML 64% 32% 3% 40% CNL 73% 11% 35% 21% CMML 44% 5% 1% 48% Meggendorfer et al., Abstract 105, ASH 2013

MDS/MPN with CBL mutations % Myeloproliferative features Leukocytosis (>10x109/l) 11/13 85% Myeloid precursors >10% 12/13 92% Increased BM cellularity 11/12 BM fibrosis (no grade III) 10/13 77% Splenomegaly Myelodysplastic features Anemia (<13g/dl) 13/13 100% Thrombocytopenia (<150x109/l) 8/13 62% Monocytosis (>1x109/l) Dysplasia in BM and PB 10/12 83% Prior diagnosis (n=13) CMML (n=6) MDS/MPNu (n=4) aCML (n=2) PMF (n=1) 5 patients positive for mutations in EZH2 (n=3) and TET2 (n=2) Allogeneic SCT (n=2) Three-year survival rate was 27% Schwaab et al., Annals of Haematology 91; 2012: 1713

No abnormality defines specific disease entities except BCR-ABL Classes of somatically acquired driver mutation in MPN, MDS/MPN and MDS SIGNAL-LING EPIGE-NETIC mRNA SPLICING TRAN-SCRIPTION COHESIN CYTO TK fusions JAK2 MPL CBL NF1 NRAS KRAS CSF3R RIT1 PTPN11 FLT3 KIT SETBP1 CALR TET2 DNMT3A IDH1/2 EZH2 ASXL1 PHF6 CREBP EP300 SF3B1 SRSF2 U2AF1 ZRSR2 LUC7L2 PPRF8 RUNX1 TP53 ETV6 BCOR CUX1 STAG2 SMC1A SMC3 RAD21 5q- -7/7q +8 +19 i(17q) del(11q) del(12p) del(20q) inv(3q) t(3;3) No abnormality defines specific disease entities except BCR-ABL

Molecular heterogeneity in MDS/MPN and MPN Molecular aberrations initiating modifying transforming cooperating no functional role RAS RUNX1 TP53 ... Genetic predisposition Genotype in mice Familial MPN Haplotype 46/1 JAK2 V617F JAK2 exon 12 CALR MPL KIT D816V Phenotype Progression SF3B1 SETBP1 SRSF2 ASXL1 CSF3R TET2 EZH2 ...

Biology of MDS/MPN: conclusion Diagnosis Challenging Overlap of morphologic findings Pathogenesis Mutations in various genes Molecular heterogeneity Some of them rather disease-specific Prognostic relevance Prognosis Poor Thrombocytosis is a favourable risk factor Increasing importance of the mutational profile Treatment No targeted treatment Allogeneic SCT is rarely performed Current strategies do not affect progression or survival