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Acute Myelogenous Leukemia and Myelodysplasia- Highlights of ASH 2013. Gary J. Schiller, M.D., F.A.C.P. Professor of Medicine Director Hematological Malignancies / Stem Cell Transplant Program David Geffen School of Medicine at UCLA. A Static Therapeutic Landscape.
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Acute Myelogenous Leukemia and Myelodysplasia- Highlights of ASH 2013 Gary J. Schiller, M.D., F.A.C.P. Professor of Medicine Director Hematological Malignancies / Stem Cell Transplant Program David Geffen School of Medicine at UCLA
A Static Therapeutic Landscape • Statistical hazards in evaluating new interventions • Limitations on the definition of response viz. survival • Limitations in the regulatory pathway toward approval of novel agents
What Defines Risk in Acute Myelogenous Leukemia? • Clinical Variables • Antecedent hematologic disturbance • Advanced age at presentation • Leukocytosis at presentation • Male gender • Elevated LDH at presentation
What Defines Risk in Acute Myelogenous Leukemia? cont’d… • Biologic Variables • Adverse Cytogenetics • Monosomies • Complex (≥ 3) abnormalities • inv(3), t(3;3), t(6;9), t(6;11), t(9;22), 17p • Less-certain adverse cytogenetic features • 11q23
Refinements in Risk Stratification • Recurrent single-gene mutation • Mutations in kit • flt3 ITD • Routine molecular studies • Investigational molecular studies
Routine Evaluation of AML for the Purpose of Risk-Stratification • STANDARD: Morphology Flow Cytometry / Immunohistochemistry F.I.S.H. for common abnormalities: t(8;21) RUNX1-RUNX1T1 inv(16) or t(16;16) CBFβ-MYH11 t(15:17) PML-RARα t(9;11) MLLT3-MLL inv(3) or t(3;3)RPN1-EVI 1 Karyotype Molecular Studies for mutations in flt3, NPM-1, Kit, CEBPα • POTENTIALLY USEFUL: Molecular studies for mutations in DNMT3a, TET2, MLL, IDH1, IDH2 • INVESTIGATIONAL: Molecular studies for mutations in ASXL1, PHF6, BCOR, CEBPε
Cytogenetic and Molecular Findings Characteristic of Newly-Diagnosed High-Risk AML • Cytogenetic Classification • Intermediate Risk • Normal • +8 • Unfavorable Risk • -5/-7 • 11q23 • 20q- • ≥ 3 abnormalities • Favorable-Risk • t(8;21) • inv(16) or t(16;16) • Mutation • flt3 ITD • Mutant TET2, MLL-PTD, DNMT3a, ASXL1, PHF6 • Kit
Distribution of acute myeloid leukemia patients with intermediate-risk cytogenetics with intermediate mutational risk (Patel JP et al. N Engl J Med.2012;366(12):1079-1089)
Further Clinical Features in Risk-Stratification for AML • Impaired performance status • Co-morbid medical conditions • Disease refractory to conventional induction • Disease relapsed after • allogeneic hematopoietic progenitor cell transplant • recent completion of consolidation chemotherapy
Treatment Strategies for the Management of High-Risk AML • Dose-intensified induction chemotherapy
Dose-Intensified Induction Chemotherapy for AML • No significant survival benefit for AML with flt3 ITD or MLL-PTD. • Survival advantage in favor of higher-dose DNR among those with intermediate- and favorable-risk cytogenetics, not among those with unfavorable-risk karyotype in ECOG study • Greatest benefit in the HOVON/AMLSG/SAKK for high-dose DNR achieved in patients age of 60-65, and for patients with CBF leukemias • No benefit was seen in patients with AML characterized by “very unfavorable” karyotype
Other Dose-Intensification Strategies • Cytarabine • Mitoxantrone and Etoposide • Autologous transplantation
Hazards of Interpreting Trials of Dose-Intensification • Enrollment typically not done on the basis of disease-related or clinical variables • analysis of subgroups, and conclusions, are post-hoc • Randomized trials of novel therapy generally do not restrict or define post-remission management • None of the studies attempt to improve outcome based on distinct AML subtypes
When is Investigational Therapy Warranted for AML? • Refractory and “Early” Relapsed AML • Newly diagnosed AML characterized by adverse cytogenetic + molecular high-risk factors • AML in those over age 70 • Potential Options • Cytotoxic, Molecular, Immunotherapeutic Agents
CLASSIC 1 High-dose Cytarabine +Clofarabine Trial in Refractory and Relapsed AML • Eligible patients • Age ≥ 55 • At least 1, but no more than 2, prior inductions • At least 3 months from last HDAC • Recommended, but not prescribed post-remission treatment plan
CLASSIC 1 Trial Results • Response Rate • EFS at 4 mos • Response Duration • Deaths as a result of AE’s • Survival ara C(1g/m2/d) araC + Clo (40 mg/m2/d) 22.9% 46.9% 16.6% 37.7% 3.8m 7.6m 5.2% 14.3% 6.3m 6.6m
Immunotherapeutic Approaches of High-Risk AML • Tumor Antigens • Immunomodulatory Agents • Induction of autologous anti-leukemia reactivity • Allogeneic hematopoietic stem-cell transplantation
Allogeneic Hematopoietic Stem-Cell Transplantation in High-Risk AML
Potential Flaws in the Methodological Design of Studies in High-Risk AML • Heterogeneous population and disease biology • Heterogeneous post-remission therapy • Heterogeneous end-points that define “success” with an over-reliance on survival as a primary endpoint • Notwithstanding design flaws, several classes of agents are being actively studied
IPSS-R: Prognostic Risk Category Clinical Outcomes ***Medians, years ^Median time to 25% AML evolution*Greenberg, Tuechler, Schanz et al, Revised International Prognostic Scoring System (IPSS-R) for Myelodysplastic Syndrome, Blood 120: 2454, 2012.**Schanz J et al, J Clin Oncology 2012; 30:820
Challenges for the Community of Physicians who treat high-risk AML- Summary • Treatment has been developed on the basis of clinical features more often than on biological features • Complete remission has generally been a secondary endpoint of clinical trials • Heterogeneity of post-remission strategies have a significant impact on the use of survival as a primary endpoint • The end-result of clinical-trial strategy has been a static treatment paradigm based on limited drugs