Introduction: Residual disease (RD) after autologous transplantation as well as following induction therapy in multiple myeloma (MM) patients ineligible for transplant is associated with inferior ...survival. The significance of RD quantified by multiparameter flow cytometry (MFC) in the setting of allogeneic hematopoietic stem cell transplantation (HCT) for MM has not been reported. Using MFC we assessed the likelihood of RD clearance after HCT and assess whether RD status before HCT and at 1 and 3 months after HCT was associated with survival.
Methods:We include 51 consecutive patients who underwent HCT for high-risk relapsed MM at our center between January 2014 and October 2016. All received CD34+ selected peripheral blood stem cell grafts. Donors included matched related (n=15), matched unrelated (n=20) and HLA 9/10 mismatched unrelated (n=16). The preparative regimen included busulfan (0.8mg/kg x 10 doses), melphalan (70mg/m2 x 2days), fludarabine (25mg/m2 x5days) and rabbit ATG (2.5mg/kg x 2 days).
RD was assessed using MFC at 3 time points (TP) including TP0: median of 28 days (14-64) before transplantation (n=51), TP1: median of 28 days (range 26-55 days) after HSCT (n=48) and TP2: median 97 days (range 90-180days) after HSCT (n=43). MFC RD analysis was performed on marrow aspirate samples using 8-color flow analysis with sensitivity of 0.01% of white cells in 2013-till December 2015 and 10-color flow analysis with sensitivity of 0.0005% subsequently.
Standard criteria were used to define categorical MM disease response. Overall survival (OS) was assessed using the Kaplan-Meier method and groups were compared using the log rank test. A landmark analysis was performed to assess the significance of MRD status at TP1 and TP2, with patients who relapsed or progressed within 30 days of the respective TP excluded from the landmark analysis.
Results:Themedian age was 55 years (range 35-67). All patients had undergone prior autograft. Twelve experienced disease progression or relapse and 21 died, including 7 deaths due to relapsed MM and 14 due to transplant related mortality. The median follow-up amongst survivors (n=30) was 524 days (97-1089 days). Categorical disease status at HCT included: CR (n=9), VGPR (n=12), PR (n=21) and SD/PD (n=9) and this was associated with RD status. Detected RD was noted in 2/9 (22%), 8/12 (67%), 18/21 (86%) and 6/9 (67%) patients in CR, VGPR, PR and SD/PD, respectively (p=0.01).
At TP0 34/51 had RD including all 13 with ≥5% marrow plasma cells. At TP1 31/48 were RD- (3 did not undergo RD assessment at TP1 due to TRM 49, 50 and 122 days after HCT). Of the 31 who were RD+ at TP0 and had assessment at TP1, 15 became RD- (48%). Sixteen of 17 who were RD- at TP0 remained RD- at TP1 and only 1 became RD+. Between TP1 and TP2 the concordance of MRD status among 43 patients who had assessment at both time points was 81% (RD+ at TP1 and TP2 n= 12, RD- at TP1 and TP2 n=23). Two became RD- at TP2 and 6 (14%) became MRD+, 4 of whom died due to MM.
Categorical disease status before HCT was associated with RD status at TP1 and TP2. At TP1, 3/20 (15%) evaluable patients who were in CR or VGPR before HCT were RD+, compared to 14/28 (50%) who were in PR/SD or PD (p=0.016). At TP2, 3/19 (16%) evaluable patients who were in CR/VGPR prior to HCT were RD+ compared to 15/24 (63%) who were in PR/SD or PD (p=0.004). (Table 1)
Conclusions: HCT resulted in the clearance of RD at TP1 in 48% of patients. Unlike autologous transplantation and pharmacologic therapy, HCT benefited MM patients irrespective of pre HCT RD status. Recurrence of RD by MFC was identified in 14% of patients between TP1 and TP2 suggesting this may be an optimal time to intervene with post transplant maintenance strategies. Improved RD sensitivity may be needed to better assess progression risk of MM post HCT.
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Koehne:Atara: Consultancy, Patents & Royalties.
Highlights • Approximately 80% of MDS patients below the age of 75 are eligible to undergo transplant. • Only one third of all MDS patients referred to an academic center undergo transplant • Death ...due to MDS and disease progression are the major barriers to transplant. • Patients aged over 65 were less likely to be referred for transplant evaluation and were less likely to undergo transplant.
Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell malignancy with features of both a myeloproliferative neoplasm and a myelodysplastic syndrome. We present a case of ...72‐year‐old man with CMML who presented with generalized hemorrhagic papules and plaques which on histopathology showed a peculiar infiltrate of atypical mature histiocytes. The immunohistochemical markers for Langerhans cells, indeterminate dendritic cells, and plasmacytoid dendritic cells were negative. Next generation sequencing performed on the paraffin block of the leg biopsy specimen revealed identical ASXL1, SRSF2, and KRAS mutations as seen in the CMML clone of the peripheral blood. Along with recent literature, this case illustrates the spectrum of histiocytic and dendritic cell proliferations in CMML, many of which may be clonally related to the hematopoietic malignancy.
•Mixed phenotype acute leukemia had a predominance of acute lymphoid leukemia–type mutations and cytogenetic abnormalities•Remission induction rates were high with both acute lymphoid leukemia–type ...and acute myeloid leukemia–type induction regimens•Survival was high after allogeneic transplantation with ablative conditioning•Mixed phenotype acute leukemia with MLL rearrangement has an unfavorable prognosis
Mixed phenotype acute leukemia (MPAL) represents a poorly characterized group of acute leukemias that lack an accepted therapeutic approach and are typically associated with poor outcomes. We present our experience of genomic profiling, pretransplantation therapy, and transplantation outcomes for 36 well-characterized pediatric and adult patients with MPAL, defined according to the 2016 World Health Organization leukemia update. A predominance of acute lymphoid leukemia (ALL)–associated mutations and cytogenetic abnormalities was noted. Remission rates after induction appeared comparable among adults (20 of 23) and children (11 of 13) and among those who received ALL (10 of 11) or acute myeloid leukemia–type (21 of 25) induction. Adults underwent transplantation in first remission while children underwent transplantation in the setting of relapse or MLL rearrangement. The median follow-up among the 25 patients who underwent transplantation was 39.6 months and median overall survival was not reached. Relapse after transplantation was associated with MLL rearrangement (P = .022), reduced-intensity conditioning (P < .001), and higher WBC at diagnosis (P = .034). These data highlight differing therapeutic approaches between adult and pediatric MPAL and demonstrate favorable survival of adult MPAL patients consolidated with allogeneic hematopoietic cell transplantation.
Few studies have compared treatment outcomes and disease complications between classical and variant hairy cell leukemia (HCL).
We reviewed records of patients (pts) with HCL treated at Memorial ...Sloan Kettering Cancer Center between 1983 and 2013 and identified 331 pts. To reduce bias we limited analysis to the 183 pts who were reviewed and treated at MSKCC within 3 months of diagnosis (table 1).
The median follow-up was 46.8 months. Median overall survival (OS) for the entire cohort was not reached and 5 and 10 year OS was 94% and 83% respectively. Median OS for classical and variant HCL was not reached in either group (Fig 1) while 5 and 10 year OS appeared equal. The time to next treatment (TNT) following initial therapy was longer for classical HCL (Fig 2). Pts with classical HCL were also more likely to achieve remission with first therapy and required fewer individual lines of therapy (Table 1). Cladribine was used first line in 122 pts and resulted in a median TNT of 138 months (97.1-NA), pentostatin was used in 9 pts and resulted in similar remission duration as cladribine with TNT of 81 months (80.5-NA) (p=0.82). 5 pts had abnormal cytogenetics at diagnosis and this did not influence OS when compared to the 62 pts who had a normal karyotype with estimated 5 year OS of 100% and 97%, respectively.
31 pts required treatment for disease relapse. The median time to 3rd therapy was not reached however 72% and 52% of all pts were estimated to require a 3rd treatment at 5 and 10 years, respectively. Cladribine was used to treat 1st relapse in 18 pts while 5 were treated with the combination of cladribine and rituximab. This resulted in a median TNT of 66.3 (37.2-NA) months in the cladribine group, median TNT was not reached for the combination group. We found that initial treatment of HCL with cladribine appeared to result in a longer disease remission when compared with the second treatment with a median TNT of 138 and 66 months respectively. 22 pts died during follow up, with 2 deaths due to HCL, 6 due to secondary malignancy, the remainder were unknown.
27 Secondary cancers were identified the most common were non-melanoma skin cancer (5), prostate cancer (5), melanoma (4) and other lymphoproliferative disorders (4). The most common reasons for needing retreatment varied depending on disease type with the recurrence of cytopenias accounting for 23/25 pts with classical HCL and only 1 with variant HCL. Symptomatic splenomegaly prompted re-treatment in 4/5 with variant and 3/25 classical HCL. B symptoms were uncommon occurring in 1 pt with classical and 1 with variant disease at relapse. The major complication of 1st therapy was febrile neutropenia necessitating admission for intravenous antibiotics, which occurred in 40/139 pts. There were no mortalities due to bacterial sepsis following 1st therapy.
We conclude that OS of pts with HCL variant is equal to that of classical disease; however patients with classical HCL have a far longer duration of first remission and a greater chance of complete remission. Patients with variant HCL have different clinical features at relapse and appear to require more lines of therapy to maintain disease control. We found that responses to cladribine following first treatment appear longer than for second treatment. The combination of cladribine and rituximab may result in a longer second remission. We did not find a higher incidence of secondary malignancy in patients with variant HCL.
Table 1Comparison of patients with classical and variant HCL.Classical HCL (N=146)Variant HCL (N=10)Median age (range)52 (27-84)67 (39-78)P=0.005Men (%)114 (78%)6 (60%)Median WBC at diagnosis3.7x10^9/L9.7x10^9/LCD25 expression146/1460/10BRAF* (V600E mutated/ assessed)3/61/2Number needing therapy10910Indication for re-treatment255Cytopenia23/251/5splenomegaly3/254/25Median OSNot reachedNot reached5 year OS94%100%10 year OS84%67%TNT following 1st treatment (months)12020P=0.002CR to 1st therapy87/1095/10Median number of therapies (range)1 (0-7)4 (2-7)Splenectomy13Secondary cancers270Deaths151*BRAF mutation was infrequently assessed as we analyzed patients up to 2013.
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Park:Actinium Pharmaceuticals, Inc.: Research Funding; Juno Therapeutics: Consultancy.
Cytogenetic analysis of a large cohort of hairy cell leukemia (HCL) patients (pts) has never been reported. The influence on outcome of cytogenetic abnormalities is unknown.
We retrospectively ...reviewed records of pts with HCL treated at Memorial Sloan Kettering Cancer Center between January 1973 and December 2013. 501 pts were identified and 331 were confirmed to have a diagnosis of HCL by histopathology or immunophenotyping. 170 patients were excluded, either because their final diagnosis was an alternate disease or there was inaccessible clinical data. Descriptive statistics were used to evaluate the cohort.
260/331 (79%) were men, overall median age at diagnosis was 53 years (range 20-84 years) and median follow-up was 61 months. 241 had classical HCL and 18 had variant disease based on absent expression of CD25 by immunophenotyping or immunohistochemistry with median diagnostic WBC of 3.2x10^9/L and 8.4x10^9/L respectively. BRAF mutation testing was performed infrequently (<10% pts). In 72 pts we were unable to review immunophenotyping data to confirm disease type. 64 pts never received treatment, 156 received one line and 111 received at least 2 lines of therapy during follow up. The most common initial treatment was cladribine (n=215, 80%). Assessment of bone marrow cytogenetics was available in 105 of 331 patients (32%) at diagnosis with 92 cases of classical HCL, 8 variant HCL and 5 with unconfirmed disease type. Karyotype was normal in 95 patients (90.5%) and abnormal in 10 (9.5%). Abnormal karyotype was more common in patients with variant than classical disease, seen in 3/8 versus 7/92 respectively (p=0.007). 9/10 with abnormal karyotype had multiple clones identified including at least one cytogenetically normal metaphase. Sex chromosome loss was present in 4/10 pts (3 with loss of Y and 1 female with loss of X) while loss of genetic material from chromosome 7 was the most common autosomal abnormality (3/10 patients). The presence of an abnormal karyotype at diagnosis did not worsen survival compared to patients with a normal karyotype with an estimated 5 year OS of 100% and 97%, respectively.
30/111 pts (24 classical and 6 variant HCL) who received two or more lines of therapy had cytogenetics evaluated at some point during disease relapse and 17/30 had cytogenetic abnormalities. 6 of these had cytogenetics at diagnosis and 4/6 were normal. Pts with an abnormal karyotype received more lines of therapy prior to identification of a cytogenetic abnormality than those with normal cytogenetics with a median of 3 and 1 lines respectively (p=0.008). Pts with variant HCL were more likely to have abnormal cytogenetics at relapse (6/6) than those with classical disease (11/24) (p=0.017).
Cytogenetic abnormalities of all evaluable pts with relapsed HCL were reviewed. The most common abnormalities seen at relapse were monosomies or partial chromosome deletions seen in 14/17 cases. The most common abnormalities were loss of material from chromosome 7 (6/17 pts) and chromosomes 13 and 17 (4/17 pts each). Multiple abnormalities were present in 11/17 pts. No abnormality appeared to be specific for classical or variant disease. In particular loss of material from chromosome 7 was seen in both disease types. Only 2 of the 331 pts developed a therapy-related acute myeloid leukemia (t-AML) both had classical HCL. The first developed t-AML with a complex monosomal karyotype after prior treatment with cladribine, pentostatin, fludarabine and rituximab. The second had t-AML with monosomy 7 following 4 treatments with cladribine. There were no cases of myelodysplasia.
In summary we identified cytogenetic abnormalities in 10% of newly diagnosed HCL pts and found that this did not adversely affect survival. Pts with variant HCL are more likely to have abnormal cytogenetics at diagnosis and at disease relapse compared to those with classical disease. Cytogenetic changes appear to be more common in those who received more lines of cytotoxic chemotherapy. Loss of material from chromosome 7 is the most common cytogenetic change seen at diagnosis and at disease progression. The rate of therapy-related myeloid malignancies is low and is not increased in HCL variant. Identification of new molecular mutations arising during disease relapse may be insightful.
Park:Actinium Pharmaceuticals, Inc.: Research Funding; Juno Therapeutics: Consultancy.
Mixed phenotype acute leukemia (MPAL) is a rare form of acute leukemia, and comprises 2% of all acute leukemia diagnoses. With the exception of a small subset harboring BCR/ABL1 or MLL translocations ...(around 15% in combination), the genetic aberrations of MPAL are largely unknown. PHF6 gene is located at Xq26-27 and encodes plant homeodomain finger 6, a zinc finger containing protein. Recurrent somatic PHF6 mutations are frequent in T-ALL (up to 30%) and rarely in AML (~3%). Here we report recurrent PHF6 mutations in approximately 20% of MPAL patients, making PHF6 the most common genetic aberrations identified in MPAL.
From 2013 to 2016, a total of 1329 patients with myeloid neoplasms were sequenced at the MSKCC with a targeted next generation sequencing panel containing 30 genes that are frequently mutated in acute leukemia. We identified 38 PHF6 mutations with predicted pathologic significance in 33 patients (2.5%) spanning the whole coding sequence: 10 frameshift, 11 nonsense, 1 splicing site, and 16 missense (Figure 1). The most common co-mutant gene observed in cases with PHF6 mutations was RUNX1 (30%, 11/37). No TP53 mutations are detected within the PHF6-mutant cohort(Figure 2). The 33 patients with PHF6 mutations included patients with a diagnosis of MPAL (n=5), AML (n=19), MDS (n=5), and MPN (n=4).
The disproportional distribution of PHF6 mutations in MPAL prompted us to further analyze these patients. During the same period of time, 24 MPAL patients were identified and confirmed based on WHO 2016 classification (excluding AML-MRC and t-AML). Within this cohort, 3 (12%) had BCR-ABL1 (p190) fusion, and 1 (4%) had MLL translocation, two distinct genetically defined subgroups. Importantly, 5 (21%) harbored PHF6 mutations, these mutations were mutually exclusive with BCR-ABL1 or MLL. Four of the 5 patients showed T-cell lineage differentiation, in contrast to MPAL with BCR-ABL1 or MLL translocations which were characterized by B/myeloid differentiation. The 2-year overall survival for the PHF6 mutation positive MPAL was markedly reduced compared to non-mutated cases (40% vs. 100% in PHF6 unmutated cases (p=0.005)).
In the larger subset of AML cases, PHF6 mutations were nearly exclusively present in secondary AML (11 AML-MRC, 6 t-AML and only 1 de novo AML). In contrast to their rarity in de novo AML, PHF6 mutations were identified in 11% (11/88) of AML-MRC and 7.1% (6/84) of t-AML. Interestingly, T-cell markers (cytoplasmic CD3, CD2, CD5, CD7) were often expressed on the blasts of secondary AML cases regardless of PHF6 mutational status (56%, 9/16 vs. unmutated 51%, 36/70). In comparison to unmutated cases, the blasts were often negative for CD33 (69%, 11/16, vs 28%, 20/70, p=0.004 by Fisher's exact test) and CD38 (44%, 7/16, vs. 17%, 12/70, p=0.04 by Fisher's exact test) in PHF6 mutated AML, suggestive of a stemness phenotype with aberrant T-cell differentiation.
In conclusion, PHF6 mutations are the most common somatic alteration identified in MPAL and define a subgroup of MPAL with altered T-cell differentiation and inferior outcome. Amongst AML, PHF6 mutations are almost exclusively seen in secondary AML and are also associated with T-cell antigen expression and a more primitive stem/progenitor immunophenotype. PHF6 mutations co-exist with RUNX1 mutations but are mutually exclusive to TP53 mutations. Notably, PHF6 mutations may provide a genetic and functional link between MPALs with poor outcome and secondary AML and provide insights into shared mechanisms of transformation. RNA sequencing studies on the sorted blast population are ongoing and will be presented at the ASH meeting.
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Arcila:Invivoscribe: Honoraria; Archer: Honoraria; Raindance Tecnologies: Honoraria. Levine:Celgene: Research Funding; Roche: Research Funding; Qiagen: Equity Ownership; Roche: Research Funding; Celgene: Research Funding; Qiagen: Equity Ownership.
Introduction: MF is a Philadelphia-negative myeloproliferative neoplasm (Ph-negative MPN) with an heterogeneous outcome. In 2009, Cervantes et al. published the International Prognostic Score System ...(IPSS) to better determine outcomes in this disease. In the last decade, several recurrently mutated genes have been described in MF, some of them associated with prognostic impact in survival. We propose a novel prognostic score that incorporates molecular and cytogenetic data in patients with MF.
Methods: We analyzed clinical, cytogenetic and molecular data from 623 patients with a diagnosis of primary MF (N=445), post-PV MF (N=109) and post-ET MF (N=69). Data was extracted from medical records at time of sample collection for analysis. Mutation data was obtained by next-generation sequencing analysis, performed with either paired tumor-normal whole exome sequencing (N=46) or selected gene panel for genes associated with myeloid malignancies (N=577). The following 16 genes were analyzed in all 623 patients and were considered as the common denominator for analysis: ASXL1, CALR, DNMT3A, EZH2, FLT3, IDH1, IDH2, JAK2, KIT, KRAS, MPL, NRAS, RUNX1, TET2, TP53, WT1. RAS mutations were considered as oncogenic mutations in NRAS and/or KRAS. Molecular high risk (MHR) mutations were considered as mutations in any one of the 4 genes: ASXL1, EZH2, IDH1, IDH2 (SRSF2 mutations were not included since they were not evaluated in all cases). Cytogenetic data was stratified into 4 risk categories (based on Tam et al, Blood 2009): (1) Diploid; (2) Del(13q)/Del(20q)/Trisomy 9; (3) Abnormalities of chromosomes 5, 7, 17 and complex karyotype; (4) Other abnormalities. To develop the model, the data was split into a training dataset (N=434) and a test dataset (N=189). Variables initially included in the initial training model were those with a p-value<0.05 in the univariate analysis; subsequently, this initial model was internally validated with a bootstrap procedure for stepwise backwards selection and determination of variables to be included the final model. Score points were assigned based on the value of the hazard ratio (HR). The final model was externally validated in the test dataset. Akaike information criterion (AIC) was calculated on the final model and on the Dynamic IPSS (DIPSS) model on the full dataset, and the best model was considered the one with the lowest AIC value and the highest AIC weight.
Results: In the training cohort, after a median follow-up of 30.8 months, there were 176 deaths (40.5%). The initial variables included in the multivariate Cox model were: age (>65 years), hemoglobin (<10 g/dL), white blood cell count (WBC; >25x109/L), peripheral blood blasts (>1%), presence of constitutional symptoms, sex (male vs female), platelet count (<100x109/L), type of JAK-STAT driver mutation (CALR vs JAK2 vs MPL vs Triple-negative), karyotype risk category, presence of MHR mutations and presence of RAS mutations. After bootstrapping, variables sex, peripheral blood blasts and WBC were excluded, and the final model with associated HRs is presented on table 1. Since most HRs were near 1, 1-point was given to each variable, with the exception of Triple-negative molecular status and RAS mutations (2 points each). We grouped patients based on similarity of HR into three risk categories: low (0-2 points; N=243), intermediate (3-4 points, N=141) and high (5+ points, N=50). These 3 groups were associated with significantly different survival outcomes (Figure 1): 3-years OS was 71% (95% CI 64-78%), 38% (95% CI 29-50%) and 18% (95% CI 9-37%) for low, intermediate and high risk groups (P=1.33e-13). Validating the model on the test dataset revealed significantly differences in OS among the 3 risk categories (Figure 2): 74% (95% CI 63-86%), 50% (95% CI 36-68%) and 16% (95% CI 6-39%) (P=1.42e-11). Analyzing the full dataset, the novel score model had a lower AIC than the DIPSS model (2713 vs 2722) and a higher AIC weight (0.99 vs. 0.01).
Conclusion: Incorporating molecular data, including MHR mutations, karyotype and RAS mutations leads to the development of an improved prognostic model. Further validation of this model in other cohorts is necessary. The impact of novel therapies should be evaluated among the different risk categories.
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Rampal:Stemline: Research Funding; Celgene: Honoraria; Constellation: Research Funding; Incyte: Honoraria, Research Funding; Jazz: Consultancy, Honoraria. Verstovsek:Celgene: Membership on an entity's Board of Directors or advisory committees; Italfarmaco: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Consultancy.
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